Oral History Transcript — Dr. Gordon Newkirk
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Gordon Newkirk; June 1, 1983
ABSTRACT: Discusses his youth and early interest in astronomy; his education; undergraduate years at Harvard; interest in solar work; fellowship at Agassiz Station; his interest in rocket astronomy; Whipple and interest in rocket astronomy; graduate work at University of Michigan; solar space astronomy and V-2s; Leo Goldberg and infrared spectroscopy; Army career and assignment to the Signal Corps Engineering Labs; Coronagraph work; development of the sky photometer and Jack Evans; interest in balloon astronomy; Schwarzschild and Stratoscope; first flight in Minneapolis of Coronascope; improving the photometer; Tousey; light scattering problems.
DeVorkin: Dr. Newkirk, I know you were born in Orange, New Jersey on the 12th of June, 1928. But I know nothing else about your family, your early home life. Could you give me a review?
Newkirk: Until I went to college, I lived in West Orange. My Father was an engineer with the Public Service Electric and Gas Company. His name was Gordon Allen Newkirk as well. My Motherís name was Mildred Newkirk.
DeVorkin: Her maiden name?
Newkirk: Her maiden name was Fleming. My Motherís parents had come over to this country in the middle part of the 1800s. My grandfather started out as a carpenter and then sort of made good in the New World, and became a builder and developer.
My Fatherís ancestors had been in the New World since the founding of New Amsterdam, and one can trace through the very early 1700s, various and sundry Newkirks; although it was originally van Nieukirk.
DeVorkin: What was their primary trade?
Newkirk: They seemed to have been doctors and businessmen, such things as that. They Anglicized the name when the British took over.
DeVorkin: That makes sense. You say your Father was an engineer.
Newkirk: He was an electrical engineer.
DeVorkin: Are you the oldest?
Newkirk: I was the only child.
DeVorkin: How would you describe your economic status when you were born, and your early home life?
Newkirk: You could describe it as comfortable middle class. We lived in a mixed residential area. We had enough resources that in the summertime we would go up camping in the Adirondack Mountains every year.
DeVorkin: Was there any effect of the depression on your Fatherís work?
Newkirk: Yes. He never lost his job, but I can remember my parents rather gloomily anticipating another salary cut. So it was middle income, comfortable middle income means.
DeVorkin: Yes. Did you go to private or public schools?
Newkirk: No, I went to public schools for the whole time.
DeVorkin: Is there anything particularly in your public school training that you feel is important in understanding your further career?
Newkirk: Yes, there were several influences. One was perhaps just being in West Orange, because that was the home of the Edison Laboratories. That was the big thing in town, the Edison Factory. Even though Edison died when I was still a very small child, there was still the image of the great inventor hanging over the town. Where we lived was immediately adjacent to what was then, and still is, called Llewellyn Park. This was a very large private residential park, which we were forbidden to go into, but of course that meant that we went into it. And we used to go ice skating on Mrs. Edisonís duck pond. But the fact that the Edison Laboratories were there meant the great inventor picture had his influence.
There were several teachers who had a great influence. One was a 6th grade teacher who had the uncanny ability to bring out the special characteristics of everybody in the class. It was a very amazing thing. I was a curious kid and always interested in science and rocks and ants and insects, everything that 6th grade kids are interested in. She really fostered this.
DeVorkin: Yes. So you were interested in the natural world.
Newkirk: Yes, but she really fostered this. And so far as astronomy, well, that was just one of those things at that stage.
DeVorkin: But it was nothing special.
Newkirk: It was nothing special at that stage. I think of the various things I was interested in, such as the natural world, as well as aircraft and things like that.
DeVorkin: Fostered by the same teacher or things you were interested in yourself?
Newkirk: Also things that I was interested in myself. This was during the war, and lots of kids were interested in airplanes, making model airplanes, and all sorts of activities such as that.
I guess it was when I was a sophomore in high school that the interest in astronomy became more intense, not particularly because of any stimulation by a particular teacher, although I did have a physics teacher at that time who really stimulated my interest in physics as such. And thatís when I decided that I really wanted to get more seriously interested in astronomy, and did the thing that most kids do at that age. I built myself a telescope.
DeVorkin: So it was the physics teacher who got you interested in astronomy?
Newkirk: No. I was becoming more seriously interested in it on my own, but the accumulated effect of his being very supportive and stimulating my interest in physics accelerated the interest in astronomy. I decided, well, I really wanted to do something more serious in this way.
DeVorkin: Do you recall if he had talked about how physics and astronomy were related or becoming related?
Newkirk: I canít remember that, no.
DeVorkin: Okay, so nothing on that. Letís see, this was just a few years after the atomic synthesis of Hans Betheís work on the energy source of the sun.
Newkirk: I canít remember that at all. That was the stage when I started voraciously reading, for example, the books of George Gamow, making my own telescope, reading textbooks on astronomy, that sort of thing.
DeVorkin: Yes. What kind of telescope did you make?
Newkirk: I made a 6-inch mirror telescope. I still have the mirrors as a matter of fact, speaking of historical relics (laughs).
DeVorkin: Did you make it from a book? Or did you have friends, or mentors who guided you?
Newkirk: No, I made it from a book.
DeVorkin: Which book was that?
Newkirk: It was the AAVSO book, AMATEUR TELESCOPE MAKING, by Albert Ingalls.
DeVorkin: Did you join any clubs?
Newkirk: No. I wasnít aware of any clubs available. We were right outside of New York City, and going to the Hayden Planetarium was the sort of thing that I thought of as a big excursion.
DeVorkin: So that was nothing you could do on your own.
Newkirk: No, not until I was older and no longer interested in going to the Hayden Planetarium. During high school I was fairly socially awkward. So I concentrated a tremendous amount of energy, not necessarily in school work, but in doing these amateur science activities.
DeVorkin: This was on your own, rather than in a club.
Newkirk: This was on my own, rather than in a club, and the telescope led then to building a spectrograph, and building spark gaps and all sorts of things like that. I tried to build a spectroheliograph but could never make it work.
DeVorkin: This was in high school?
Newkirk: This was in high school.
DeVorkin: Did you build these at home?
Newkirk: Yes, I built them in the basement.
DeVorkin: Where did you get your optics and equipment?
Newkirk: The mirror I ground, but then all the subsidiary optics, such as flat mirrors and things like that, I obtained in New York City — I canít remember the name of it — from an amateur astronomy warehouse, which had a catalog where you could send off and buy a prism, or a very small grating, or such pieces as that. Most of the mechanical parts, I just had to make myself. So things were very much ďcludgedĒ together.
DeVorkin: Yes. Did your spectrograph work?
Newkirk: Oh yes, sure.
DeVorkin: How faint did you get?
Newkirk: Well, I used it on the sun.
DeVorkin: I see, so you didnít try for stellar spectra.
Newkirk: I didnít try for stellar spectra at all.
DeVorkin: When you used it on the sun, what did you do with the spectra? Did you identify the lines at all?
Newkirk: I identified some spectral lines and also tried to determine the rotation of the sun, but that was unsuccessful. The spectroheliograph, I think, probably would have worked; but I could never, using just plywood, make a smooth enough motion for a spectroheliograph to work.
DeVorkin: So your substance of choice or necessity was plywood?
Newkirk: Necessity. I didnít have any metal working facility at all.
DeVorkin: That was before the age of teflon.
Newkirk: Yes, right. I remember I also made a device to try to measure the brightness of variable stars. It basically was a gadget which produced an artificial star in the field of the telescope. I could vary the brightness of the artificial star with a rheostat. I thought I could use that to have a controlled comparison star immediately in front of my eyes. There was a failing and that was that as I changed the brightness with the rheostat that changed the color as well. It was another experiment of doubtful utility (laughs).
DeVorkin: Yes, but you clearly were becoming familiar with problems in experimental work and in observational astronomy — instrumentation problems.
DeVorkin: Was it the instrumentation that interested you most at that time?
Newkirk: Well, I donít think so. It was the making of gadgets to for example, make photographs of the sun, of the moon, of the planets. Straightforward star field photographs I somehow never got into. I didnít have any real guidance device on the telescope, so that was a practical limitation.
DeVorkin: What was your goal in making all of this? Was it to make the devices, or was it to use the devices?
Newkirk: No, to use the devices, and as I say, I tried to determine the rotational speed of the sun, and tried to identify lines on the sun by getting comparison sources. I was able to borrow some equipment from the physics and chemistry laboratory in high school. Then I could make a comparison with the hydrogen tube in the solar spectrum, and doing sodium is very easy. You just drop salt in a candle. These were still at very primitive levels.
DeVorkin: Yes, they seem to work. Did you read about spectra in any particular books that you recall?
Newkirk: Not that I can recollect. I canít remember any particular book.
DeVorkin: Can you recall seeing by that time the Russell, Dugan and Stewart two-volume book, or Menzelís book, OUR SUN, or something like that?
Newkirk: I remember that I did have one general astronomy text which was Duncanís book. That was just about the time that the Harvard books in astronomy were coming out, and so I was a great aficionado of those.
DeVorkin: That was while you were still in high school.
Newkirk: Thatís when I was still in high school.
DeVorkin: Did that affect your decision to go to Harvard at all?
Newkirk: Well, I became serious about this when I was a junior in high school. I really wanted to do astronomy.
DeVorkin: About what year was that?
Newkirk: 1944-45. And I am not actually sure how I even came across the name, but I remember writing a letter to Bart Bok at Harvard, inquiring about the profession of astronomy in general. As is probably fairly common in cases like that, my Father was convinced that going into astronomy was an invitation to starvation
DeVorkin: Oh really.
Newkirk: He felt that this was really a little bit too esoteric a thing to go into.
DeVorkin: Did he question that you should go into college; did he want something else for you?
Newkirk: There was no question that, if I wanted to, I was going to, got to college. But he just felt that astronomy was really rather a far-out sort of thing to go into.
DeVorkin: Had he encouraged you in the past to build these different pieces of equipment?
Newkirk: Yes. But he didnít help build them, except sometimes I would have something that was so big and awkward and heavy I would then ask him to help me. But it wasnít a case of his doing these projects and my standing aside to watch.
But I wrote Bok and asked him about the overall profession of astronomy. Bok wrote back and said that it was a very satisfying career. One couldnít look forward to getting rich, but one could have a very comfortable life and it was very exciting. And at the same time I was thinking, okay, Iíve got to go to college. What colleges do I go to? I think this correspondence went back and forth with Bok, because I suddenly found I had a source of information, which solved one of my real problems.
DeVorkin: So you hadnít been reading SKY AND TELESCOPE, or anything like that at the time?
Newkirk: Yes, but that didnít really tell you how to become as astronomer! (laughs).
DeVorkin: Yes, okay.
Newkirk: I asked Bok what schools one might go to for astronomy. At that time it was Harvard, Princeton, Yale, and Caltech. About the same time our physics teacher pointed out to me the Westinghouse Science Talent Searches. He suggested that I might be interested in that, and I really grabbed a hold of that as a possible challenge and opportunity with great enthusiasm. It must have been late in my junior year that I really decided, okay, I was going to participate in that contest, and really began to think what would I do for the project. And then I remembered that in November or December, they as an examination. I took the examination and also had to write an essay on what I had done in science, basically a science project. The essay was basically a description of the various things I had done in astronomy, really not a specific project. It was just a series of somewhat smaller things on observational astronomy. Some of this was observational or experimental physics, too. I remember I decided that I had read somewhere about cosmic rays, and that cosmic rays were influenced by the sun. And so I had made an expansion cloud chamber.
DeVorkin: Oh, you did!
Newkirk: So I could see cosmic ray tracks. I never saw any cosmic rays. The only tracks I ever saw were from the luminous dial of a watch. The luminous dial of a watch lets you see alpha decay particles in the cloud chamber. The cloud chamber was made out of a Silex coffee top. That was the expansion chamber. Again, it was a design which was brought on by necessity due to the crude techniques that I had available. I wanted to make an expansion chamber, and yet, I didnít know how to machine a cylinder, which would allow me to make the chamber. I decided all right, I wanted a high-humidity atmosphere in my expansion chamber, and so I used a Silex coffee top. One thing I had finally learned how to do is work glass, which was an exotic thing. Most kids at that age know how to work wood and metal, but not glass. And so I ground the top rim down until it was flat and could cement a piece of plate glass on the top. I would partially fill the thing with water, with ink in it, so that it gave a black background to look down on, and float my cast-off watch dial on a little piece of cork. And then you just squeeze on the stem of the Silex rubber bulb and let go. The expansion would then occur and you could see the particle tracks. So it worked.
DeVorkin: Fantastic, yes.
Newkirk: (laughs) I never did see cosmic rays.
DeVorkin: Did you design that completely yourself, or is that something you ready about, say in SCIENTIFIC AMERICAN, or anything?
Newkirk: I didnít get SCIENTIFIC AMERICAN. I didnít even know it existed.
DeVorkin: Or POPULAR SCIENCE?
Newkirk: No, it was in Gamowís book that I learned about cloud chambers. But I canít remember reading any recipe, or any article about how to make one, except that Gamow said that you had to have a super-saturated atmosphere. My recollection was that alcohol was the vapor of choice for condensation. So, perhaps, I had seen a description of a do-it-yourself cloud chamber after all.
DeVorkin: Thatís quite fascinating. What happened with the Science Talent Search?
Newkirk: Oh yes, that was very, very exciting, and in the early spring of 1946 I got a notice that I was one of the 40 winners. What they did at that time was to invite the 40 winners down here to Washington for a week, showed them around Washington, took them around to the various laboratories around here, attended lectures, etc. You know, it was a nice thing. Then out of those 40 they picked some small number. I canít remember what that was so would given second prize. And I remember the amount. It was $400 but $400 went a long way. It could pay part of your tuition in college in those days!
And some of the people whom I met at that time I am still in contact with. One of them is Hal (Harold) Zirin of Caltech. He and I were both interested in astronomy.
DeVorkin: Yes. Who else?
Newkirk: Oh, who is the fellow at NRL?
Newkirk: No, no, no. Iíll think of it later.
DeVorkin: Is he working in astrophysics section?
Newkirk: No, the man Iím thinking of is my age.
DeVorkin: I your tours, did you go to NRL?
Newkirk: No, that was just at the end of the war, so NRL was probably still really buttoned up security-wise. I remember one laboratory we went to was to DTM, and saw the first cyclotron I have ever seen. I wonder if they are still running that there? It must be a real period piece. Is it in the Smithsonian?
DeVorkin: Itís in the Smithsonian, yes. Itís across the Mall. Had you known by this time the work of Tousey and the V-2 spectrograph, and the use of the V-2s for science?
Newkirk: That really hadnít started yet, I donít think.
DeVorkin: It started in 1946, April to June to October.
Newkirk: Okay, but this was March.
DeVorkin: Okay, still too early.
Newkirk: This was March. Now, by that time I was an avid reader of SKY AND TELESCOPE, so that I became aware of the rocket spectrographs and all sorts of things like that, as they came out in SKY AND TELESCOPE.
DeVorkin: Letís finish with the Westinghouse thing. Did you make second prize, or first prize?
Newkirk: No the first prize was really a lot of money. That was, I remember, $2,000 apiece, which would take you through all four years of tuition, and then some, amazingly enough. No, it was $400 that we are talking about. Hal Zirin, as a matter of fact, got the same thing. Those who didnít get a second prize got a recommendation or pat on the back. But it was a recommendation that was really worthwhile, because you got attention. That was just about the time one would apply to college. People now apply to college in the previous fall, but then it was in the spring. And sort of heady with the trump of this, I decided I wanted to go to Harvard; and applied. And I didnít apply anywhere else. Looking back, you know that was really (laughs) a foolhardy thing to do.
DeVorkin: Could your family have supported you at Harvard?
Newkirk: Well, they did; but I did have some financial help both from Westinghouse and from Harvard. It did stretch my familyís finances to do this, even so. I got a tuition scholarship at Harvard which was in a certain sense nice, because as Harvard escalated its tuition through those immediate postwar years, they also escalated the tuition scholarships. The $400 was money I could use for room and board and books. So I could guess that my parents had to pay for perhaps half the financial burden.
DeVorkin: And they were willing to do this?
Newkirk: Oh yes, oh, yes.
DeVorkin: Was it because of Bart Bok and his correspondence with you then, that you chose Harvard, would you say?
Newkirk: I think that was very influential, although I canít remember his saying, ďwhy donít you come to Harvard?Ē
DeVorkin: Can you describe arriving at Harvard, and what contacts you had as an undergraduate with astronomy there, especially your first contact with Menzel, letís say.
Newkirk: Well, I remember that summer after school, 1946, taking the suggestion of one of the men who was in public service with my father, who had gone to Harvard. He said, what you should do is go up there during the summer, just for a couple of days, look things over, meet people, anybody you can get hold of. Then you will feel much better about it when you go in the fall. So thatís what I did.
DeVorkin: Good advice.
Newkirk: So I wandered around the Harvard yard and actually visited Bok. I had first met him, as a matter of fact, at the Westinghouse meeting here in Washington. Westinghouse brought in, I guess, half a dozen nationally-renowned scientists for us to meet and to give a lecture to this group of winners. Bok was one. That was my first contact with him; and then I went back there in the fall.
The Astronomy Department at that time was quite small. The professors consisted of Bok, Shapley, Whipple, Menzel and Gaposchkin. That was it. And so it was not hard to get to know people. Being a small department, they also kept very close communication, even with the undergraduates.
DeVorkin: I was going to ask about that.
Newkirk: Much closer contact, even with the undergraduates, than I think most graduate students now enjoy in the much larger departments that are common now.
DeVorkin: You were coming in just at the time when the war was winding down, and there may not have been too many students. Is that possible?
Newkirk: No, this was 1946, so there was this tremendous pulse of veterans at Harvard. They were a great stimulation to everybody academically at Harvard. I can remember our joking among ourselves that if any of us should drop by the wayside in their academic work, there were 10 other guys waiting to step into our place (laughs). The pressure was really on.
But particularly under Bokís stimulation, the undergraduates got observing experience at the Agassiz Station, which is out at Harvard, Massachusetts, fairly early. Maybe once or twice during the winter that they would pair up, one of the undergraduates with one of the graduate students who was going out to the Agassiz Station to observe. We obtained early hands-on experience.
DeVorkin: Who was your graduate partner, and what did you do?
Newkirk: The only one I remember was Jim Warwick. Heís still in Colorado. And another one was Ivan King, who was president of the AAS for awhile. And another one was Arthur Hoag, whom you probably also know.
DeVorkin: Sure. So they took you out to Agassiz. This was all for night sky work?
Newkirk: This was nighttime sky work. There was no solar work there at that time. You would go out Friday night, work Friday night and Saturday night and come back Sunday.
DeVorkin: Did you work on one of their programs, and did you do something special that you had planned?
Newkirk: No, we would do whatever routine observing there was to do.
DeVorkin: Work on the catalog cameras?
Newkirk: Work on those cameras, or the meteor cameras which were going at that time. Just learning how to run a telescope, learning how to point the telescope at the correct right ascension and declination, and how to convert to sidereal time. All sorts of things like that.
DeVorkin: Yes. So there was no practical work on campus. This was all done at Agassiz?
Newkirk: There were some teaching telescopes on campus, which were up north of the Law School. Meridian circles and such things as that. I remember there were a couple of telescopes that were available for undergraduates to use whenever they wanted. I had a roommate, Francis Chen. Heís no longer in astronomy. Heís in plasma physics, but heís a fairly outstanding plasma physicist. He was also interested in astronomy, so sometimes when it was nice in the evening we could go up and use the telescope on the campus just for the heck of it.
DeVorkin: Were you getting interested in any particular type of astronomy at this time?
Newkirk: No. The curriculum at that time, and probably now, was that if you were an undergraduate student in astronomy, you would take the elementary astronomy course, which was taken by hundreds or maybe 50 undergraduates, and then concentrate mostly on math and physics, and perhaps not run into another astronomy course until you were a sophomore, or even a junior. Only then would one run into oneís first introductory quantitative astronomy course. As a senior, youíd take a course in modern astrophysics, and one or two quantitative courses. I remember Ivan King was the person who, in fact, taught the basic quantitative astronomy at that time. He was a member of the Society of Fellows, and as such, had no formal requirements; but he decided he wanted to teach this advanced undergraduate course in astronomy for his own education, I presume.
DeVorkin: Yes. What recollections do you have — because I have heard here and there recollections — of Whippleís lecturing, or of others lecturing where they would make side comments about rocket astronomy at the time? Do you remember anything from that time about Whippleís regard for doing astronomy from rockets, or Menzelís, or Bokís or your own?
Newkirk: Of that group, I think Menzel was the only one who had any great enthusiasm for it. I can remember his describing in a seminar the early attempts of Rense to photograph Lyman alpha. I remember his describing the guiding system which was being developed at that time out at the University of Colorado. Also his describing the early rocket spectra that Tousey had gotten. By that time, about 1949-50, I was probably a senior, and I remember I knew enough about spectroscopy to know that there was speculation on the idea of what the Lyman alpha spectrum of the sun would look like. And as yet, no Lyman alpha spectrum had been produced. Things just hadnít been pushed down in the ultraviolet that far. But there was this speculation. Menzel was the one interested in it. I got the impression that the others somewhat regarded rocket astronomy as a slightly suspicious venture.
DeVorkin: I would really love it if you could expand on that a bit.
Newkirk: You mean this whole question of what peopleís attitudes were towards rocket astronomy. Of course, there was no satellite astronomy.
DeVorkin: No, this is merely with the V-2s or in the case of Rense with the Aerobees.
Newkirk: The Aerobees. I really donít remember what their attitude was. I think many felt that rockets were rather expensive. The early attempts to do astronomy were all solar astronomy, because that was the only object bright enough for the guiding systems to find. Rockets were regarded as rather expensive and not likely to produce a great deal for the money expended.
I do remember, though, at that time being aware that the Lyman alpha line had been detected. I think it was first detected by Rense.
DeVorkin: What was Menzelís reason for wanting to get to Lyman alpha? What did he hope to find?
Newkirk: Well, this is the fundamental line of the hydrogen spectrum, and for understanding the structure of the chromospheres, itís probably one of the most crucial lines. You can only do so much in the way of real analysis with just the Balmer hydrogen spectrum. The Lyman alpha and the Lyman continuum are the major sources of opacity to the radiation percolating through the chromosphere. If you are going to really understand the structure of the chromospheres, you have to have all the major lines. This was a factor that Menzel well appreciated from its basic physics. He had been involved in some of the early chromospheric eclipse spectroscopy interpretation, so it was a very, very natural outgrowth of his earlier scientific interests. Dick (R.N.) Thomas was here as a graduate student at that time, and was very heavily pushing on the inadequacies of the accepted theoretical interpretation, not just of the sun, but of other stellar spectra. Prior to that, the standard assumption that had been made in the interpretation of spectra was that all the spectral lines, all the level populations were in local thermodynamic equilibrium; that is the populations of levels could be described by one number, a temperature. Dick Thomas was, Iíd say, one of the avenging angels of nonLTE (laughs). This larger perspective didnít just come from rocket astronomy. It was a very important factor in the correct interpretation of the chromospheres of the sun.
DeVorkin: Understood. Okay, thatís good.
Newkirk: And you see, Dick Thomasí line of influence came out to the West very early in the game, because he was in Utah for quite awhile; and one of the first staff members at High Altitude Observatory was Grant Athay, after they came down from Climax. And Grant and Dick Thomas were influential in getting HAOís 1952 Eclipse Expedition off the ground. I canít really say that it was THE first modern chromospheric eclipse spectroscopy, but it was pretty close to it. Menzel had, while at Lick Observatory, made, I think, really the first quantitative chromospheric eclipse spectra.
DeVorkin: In the Ď20s?
Newkirk: In the late Ď20s, í28-29, something like that. Very little [(???)tation of those spectra were done after Menzel. Then of course came along. Dick Thomas and Don Menzel were very influential aging HAO to carry out that Khartoum Eclipse Expedition was involved in that as well.(???)]
(The text immediately above between [???] is partially missing in the original)
DeVorkin: Was Jack Evans at Harvard at the time, or at the High Altitude Observatory?
Newkirk: He was HAO at the time. I remember his coming back sometime during that period for a visit. Roberts was there for a whole semester and taught a course. So again, it was a very small group and within not too very long a time everybody knew everybody else.
DeVorkin: Yes, during your undergraduate years at Harvard.
Newkirk: Yes, during my undergraduate I knew these two people also.
DeVorkin: Were your interests moving more towards solar work? Who did you find yourself working with most when you were a senior?
Newkirk: My interest was in fact moving more toward solar work? As an undergraduate summer fellowships at the Agassiz Observatory, and so I guess it was when I was a sophomore that I first went out there. You worked the summer out there observing, and you got a small stipend to do that, so that you could keep body and soul together.
DeVorkin: What faculty member did you report to?
DeVorkin: Menzel directly?
Newkirk: Well, no, the first year Bok was the faculty member in charge of all the graduate and undergraduate students who were out at Agassiz Station. It was in a certain sense a rather freewheeling situation. There were eight or ten of us there altogether, either graduate students or undergraduates. Bok would come out once or twice a week, and the rest of the time, all these students were on their own! (laughs).
DeVorkin: Kind of nice.
Newkirk: Yes, it really was.
DeVorkin: So you organized your own observing schedules, who was to observe on various instruments?
Newkirk: I canít remember that we did that. Everybody had their own projects that they had to carry out. The first year that I was there the project was to learn how to run every telescope that was there.
DeVorkin: Including the 61-inch?
Newkirk: No, they didnít let the undergraduates loose on that. They were afraid theyíd kill themselves, or the machine would fall apart.
DeVorkin: Right, one or the other.
Newkirk: Instrumentation was not Harvardís strong point at that time. It had the reputation that if you could observe there, you could observe anywhere, because the equipment was in, letís say, such poor state of maintenance.
DeVorkin: Were you interested in fixing the equipment, or in making better equipment while you were there as an undergraduate?
Newkirk: No. But the second year I was assigned with Art Hoag, who was working with Donald Menzel, on building a photospheric camera -Ė a camera for photographing the photosphere in high resolution. I got involved in that.
DeVorkin: This was definitely ground-based.
Newkirk: This was definitely ground-based and the part that I had was the responsibility for making the guider. It was to be a guider which was a replica of the automatic guider which had been built for the Climax system.
DeVorkin: This an automatic guider, then?
Newkirk: Yes. It was one of the first of the automatic guiders to use a series of photocells. That was my part of the job, to build the guider; and Hoag was to build the rest of the thing. The project never really came to very much, however. The guider worked. The telescope worked. But the whole thing was rather frustrated by the fact that the daytime seeing at that site was abysmal. Scientifically it never came to much.
DeVorkin: I understand Menzel during this time, I recall from one of the articles that you wrote, had a coronagraph that he had based upon Jack Evansí external occulting disc design.
Newkirk: There was the climax coronagraph, which was of the Lyot design. Menzel was the pioneer who put a coronagraph in the United States. That started in the late 1930s, 1938-39. In 1940, he assigned Walt (Walter Orr) Roberts, who was then a graduate student at Harvard, to do the coronagraph and its initial observations for his thesis. And in 1940, Walt brought the coronagraph out to the Climax Station and set it up. It must have probably been the spring of 1940. By the following September they had the first coronal spectra. So that was the beginning, at least in this hemisphere, of the classical Lyot coronagraph. That instrument operated all during the war.
DeVorkin: Primarily by Walter Roberts.
Newkirk: Walt Roberts operated it. Sometime, Iím not sure whether it was 1946, 1947, right after the end of the war, Jack Evans joined Walt at Climax. In late 1948 they came down to boulder.
DeVorkin: Did they bring the observing instruments to Boulder?
Newkirk: No, they left the observing instruments up at Climax but their base of operation was moved down to Boulder.
DeVorkin: Yes. Do you know why?
Newkirk: Ah, largely just because of the difficulty of doing things up at 11,300 feet. The snow is on the ground from October through June. Just hard living, thatís all.
DeVorkin: Yes. Did they maintain an observer up there?
Newkirk: They maintained an observing staff up there, although they would sometimes go up.
DeVorkin: Were they associated with the University of Colorado?
Newkirk: At the time that they moved down, it became a joint operation between the University of Colorado and Harvard and Climax remained as a joint operation until about 1954.
DeVorkin: Letís go back to your own development. You are a senior. You are getting interested in the sun. I asked you about recollections you had about the interest of using rockets on solar studies, what other people thought about it. Iíd be very interested to know what you thought about it yourself, if you can recall that. And then Iíd like you discuss how you decided to go to Michigan.
Newkirk: Well, other than an interesting thing that was going on, I canít really remember having any particular well-formed attitude one way or the other. I wasnít saying to myself, gee, thatís something I really want to do.
DeVorkin: Was anybody else saying that?
Newkirk: Well, Menzel was interested in this from the interpretative end of things. But there wasnít at Harvard any vast enthusiasm for making solar observations from rockets at that time.
DeVorkin: Did you have any contact with Whipple on all of this?
Newkirk: Yes, mostly academic, though. He taught many of the basic courses.
DeVorkin: Did he ever talk about rocketry?
Newkirk: I canít remember his talking about it.
DeVorkin: He was on the rocket panel. He was a member.
Newkirk: Yes, thatís right, too. But he never did any experiments himself, that I know.
DeVorkin: Thatís right.
Newkirk: Although I think he perhaps had some stimulating effect on people like Curtis Hemenway and Maurice Dubin and, there was another fellow who was interested in that sort of thing. I canít remember his name
DeVorkin: In what manner did he get them interested?
Newkirk: The whole idea of making rocket samplings of micrometeors in the upper atmosphere. I think that Whipple had been stimulating work in that direction.
DeVorkin: I understand. Hemenway, later went on to do that for quite a long time.
Newkirk: Hemenway did it for quite a long time. There were several other people who were involved; but I think that Whippleís influence probably steered quite a few people into doing that sort of experiment from early rockets.
DeVorkin: Okay. Well, letís move on, if thatís all right.
Newkirk: Yes, why did I go to Michigan? Because, by then I was really very much interested in the sun. Goldberg was there. Aller was there (L. H. Aller). McMath Hulburt Observatory was there. At that time that was the most active solar observatory in the country. I talked to the people at Harvard about it. I remember Cecilia Gaposchkin saying, well, if I had that basic interest, thatís where Iíd go. So I decided Iíd go there (laughs).
DeVorkin: Did anyone try to convince you to go into stellar astronomy instead?
Newkirk: No, I canít remember that. I canít remember any vying for the studentsí attention at Harvard. I know that all through my undergraduate career Bok was a very major influence, the sort of person who always would be interested in how oneís classwork was coming, and how some of these other project were going. The reason I went to Michigan was because of a basic interest in the sun, and that was THE place where that sort of study was going on.
DeVorkin: You got there in 1950, after you graduated from Harvard.
Newkirk: I got there in 1950.
DeVorkin: And Iíd be interested to know what the atmosphere was like there, who you came into contact with.
Newkirk: Well, Aller took the lionís share of the teaching in astronomy. We would still continue with math courses and physics courses. But Aller was the one who was the most energetic, so far as teaching was concerned. Aller had several research interests; one of them was solar physics. He was going (laughs) with his foot down to the floor on the accelerator on solar abundances at that time. He and Leo Goldberg were really working hard on that one. McLaughlin was there. (Dean) McLaughlin was interested in novae. Freeman Miller was interested in galactic work. They just inaugurated the Curtis-Schmidt telescope at Michigan. My first really paying job was as night assistant on that telescope.
DeVorkin: Were you funded at all by scholarship at this time, or were you working your way through?
Newkirk: I was working my way through as a half-time research assistant. Just about everybody had research assistantships. Genuine scholarships where you did not have to work as a teaching assistant, or research assistant, were scarce as henís teeth. So the first year I was an observing assistant. The second year I was a teaching assistant. The third year I was a research assistant, but the research was my own thesis. They were able to be flexible.
DeVorkin: Iím going to ask you now, before we get into specific developments here, more about the space-oriented work.
Goldberg and Menzel, Spitzer and others did try to get involved in solar space astronomy, using V-2 rockets in 1946. They formed an astrophysical study group to obtain the spectra from the rockets. Was there any talk of this group by the time you got to Michigan, because it was centered at Michigan eventually? Now, there was rocket work done at Michigan, not by Goldberg, but by Dow over in the engineering department, Signal Corps stuff. But was there anything that Goldberg ever talked about?
Newkirk: I canít remember it at all.
DeVorkin: So it was really dead by that time, probably.
Newkirk: When was this started?
DeVorkin: It started in 1947. Goldberg had gotten some money from ONR to do all this. And it sort of petered out, is what he recalls. But Iíd be interested to know if anybody talked about it, or had any recollections of it.
Newkirk: I canít remember it at all. I just canít remember any discussion about that at all.
DeVorkin: Goldberg was very interested in the infrared.
Newkirk: Goldberg was very interested in the infrared at that time. This came about because of the development of new infrared technology. Sensitive detectors had just come in. They were made by hand by a man by the name of Cashman.
DeVorkin: Were they lead sulfide?
Newkirk: Yes. Leo got his hands on a couple of these detectors and put one in the large tower at McMath Hulburt Observatory. He was really very excited about the infrared spectroscopy of the sun. Here was a whole new spectroscopic region which was now available with reasonable resolution before. He was really, so far as I could tell, completely immersed in that by the time that I arrived as a graduate student. I think that the rocket business had perhaps turned out to be not very productive, for one reason or another; I donít know why it collapsed.
DeVorkin: The important thing is that during your years there, there was no contact with it.
Newkirk: There was no contact with it, no. He did get involved after I left, very strongly.
DeVorkin: Oh yes. The OSOs and things like that.
Newkirk: Before he went to Harvard, even; but until that time it was quiescent. His interest in the IR was probably what led me to do my own thesis on infrared spectroscopy. A whole new set of IR lines, in this case, molecular lines available. I had a free field. Thatís why I picked it up as a thesis. It was both observational and interpretative work. As a matter of fact, I didnít make the observations actually used for the thesis myself. There were two cells from Cashman. One of the cells was at Lake Angeles, McMath Hulburt Observatory. The other one went out to Mt. Wilson. Leo had made some arrangement whereby the old horizontal Snow telescope at Mt. Wilson, could be used for spectroscopy in a cooperative project with Michigan.
DeVorkin: Using the spectroheliograph, probably?
Newkirk: No, this was the old Snow telescope.
DeVorkin: Yes, the Snow had a spectroheliograph in it.
Newkirk: They converted it into an infrared spectrometer. The summer that I was out at Lake Angeles doing my thesis work I made pilot observations. Then I would tell the professional observer at Mt. Wilson what to do and he would do the observations and send me the observations in Michigan. The reason for making the final observations at Mt. Wilson was that the water vapor content in the atmosphere, in the summer particularly, at Michigan was so high that the spectra were contaminated.
DeVorkin: Yes. Were you working, what, between 6500, 7,000 angstroms, or as far as a micron, or didnít you get that far?
Newkirk: No, these were two and one-half microns.
DeVorkin: The interests then, that you had in studying the far infrared behavior of the sun do not seem to come out in your published record. Did you ever publish your thesis in any way?
Newkirk: Yes, itís in there; isnít it?
DeVorkin: For the record, we are now looking at page 3 of your vita.
Newkirk: I wonder where it is. Oh, there it is.
DeVorkin: Okay, in 1957, ďCarbon Monoxide in the Solar Atmosphere.Ē
Newkirk: Yes. What happened was that I went into the Army and the thesis didnít appear until several years later.
DeVorkin: When did you go into the Army?
Newkirk: In 1953.
DeVorkin: You got your Ph.D. then, and went right into the Army.
DeVorkin: So that was your thesis.
Newkirk: I was being pursued by the Army as I was writing my thesis. As a matter of fact, in July of 1953, I took a job at Sacramento Peak to get me off the hook long enough at least to finish writing the thesis. In the fall of 1953 I came back to Michigan, took my oral exam, then went back to Sacramento Peak for a month, and then went in the Army.
DeVorkin: I see. So the Upper Air Research Observatory was what Sacramento Peak was called in those days. From July to November of 1953 you were at Sacramento Peak.
DeVorkin: Thatís interesting. I was confused by this because there was something at the University of Colorado about that time that had the same name, or a similar name, Upper Air Laboratory.
Newkirk: Well, yes. Iím not sure whether Menzel stimulated the Air Force or stimulated the HAO, but he worked with the Air Force for quite awhile to set up a major solar observatory. That was carried out as a development project by HAO for several years. The original site surveys were carried out by HAO, so that was why there was a project which was called the Upper Air Research Observatory Project. The job was to find where to put this observatory. Roberts will be able to fill you in on more of the intricate details of just exactly what was going on then. I heard about it third-hand from Goldberg. One of the sites they picked rather early in the game was Sacramento Peak. That was in the late 1940ís. Iím not sure exactly when, 1949 perhaps, that the first people went there. Jack Evans didnít arrive until quite a bit later; I would guess 1951 or 1952.
DeVorkin: Yes, that was the origins of it then, and it was very much connected with the HAO.
Newkirk: It was very much connected with HAO and supported by the Air Force. But then I went down there in the summer of 1953, July through November, basically as a shelter to get my thesis done before I went in the Army. I was doing only my thesis.
DeVorkin: Then you got your thesis finished in the fall of 1953?
DeVorkin: And then you went directly into the Army. Now, this was a draft situation?
Newkirk: Yes. I was drafted.
DeVorkin: Okay, but did you have any choice as to what part of the Army, because you went to the Signal Corps.
Newkirk: I had no choice whatsoever. I went in basic training at Fort Bliss, Texas and tromped around in the desert there for eight weeks. There was one contact that was made on my behalf at that time by Robert R. McMath. He had connections with the people who ran the Ordnance Test Activity at Fort Bliss.
DeVorkin: I wonder how he would have had that contact.
Newkirk: I would guess it probably ran back to perhaps the war years. He was actually not an astronomer, but an industrialist. And I would guess he had connections with all variety of defense work during the war.
DeVorkin: He had no contact with Dow or others? There was a big Signal Corps group at the University of Michigan who were doing communications work, ionospheric work.
Newkirk: I havenít the foggiest idea what his contact was.
DeVorkin: You certainly had no contact.
Newkirk: I had no contact there. Of course, the time comes for assignments, and I was told that, if I wanted to, I could get an assignment at Fort Bliss. In fact I was invited, which was a rather unusual circumstance for a recruit, over to see this facility. One of the officers showed me around. It was a rather strange thing for a recruit. They were making optical trajectory measurements of rockets launched at White Sands. At the same time I had an intimation of what my other assignment was going to be, which was in the Signal Corps. I think it probably annoyed Robert R. McMath that I decided, no, I didnít want to measure the positions of rockets (laughs). The other sounded more stimulating. So I took the Signal Corps assignment, and came back here to New Jersey to the SCEL labs, Signal Corps Engineering Labs.
DeVorkin: Could the Signal Corps have possibly been a choice to get you back closer to home?
Newkirk: I didnít know that that was the end of it. I knew it was Signal Corps, and I knew that that was reputedly the place where most of the science in the Army was done at that time.
DeVorkin: I see, yes. And what were your duties and your interests in the Signal Corps? I know that you worked on the solar aureole.
Newkirk: Yes, okay. The group I was assigned to at Fort Monmouth was a meteorological group, and staffed perhaps at a 30% level by immigrant German scientists who had escaped Germany as the Russians moved in.
DeVorkin: Okay, postwar.
Newkirk: Yes. The first duties I had there were really very pedestrian ones, launching the daily balloon and that sort of thing.
DeVorkin: Was that your first contact with a balloon?
Newkirk: I guess so. These were just the standard small met balloons. I also was asked to do other specific problems such as calculations on the wind response of rockets.
DeVorkin: So you were getting back into trajectories, whether you liked it or not.
Newkirk: Yes, it was an inevitable thing in the military. You end up throwing things at each other (laugh). But as I recollect, the problem was that one fires a rocket through an atmosphere with various and sundry wind shears. The response of the rocket depends upon the structure of the winds that the rocket moves through. That was one of the first jobs that I had there. I also had quite a bit of free time to read on my own.
DeVorkin: It was purely free reading?
Newkirk: Yes. They had a liberal attitude towards the G.I. scientists. Now, we also had — you said, what were your duties — your ordinary soldierly duties like standing guard.
DeVorkin: Oh really, so you did all sorts of different things, standard soldiering as well as technical work?
Newkirk: Yes, and we were in great demand, because there werenít very many enlisted men on the base who had high security clearance. So they would have some piece of hardware which they had taken off in the boondocks for testing and it had to be guarded.
DeVorkin: You were just saying you were babysitting highly technical classified pieces of armanent or devices.
Newkirk: Yes, and the only reason they used us was because we were the only ones who had a security clearance and were undergraduates; thatís a slip of the tongue, and were enlisted men.
DeVorkin: Yes. Did you equate undergraduates with enlisted men?
Newkirk: Yes, in a certain sense, itís the same sort of thing (laugh). I canít say that the whole experience was objectionable. It was a way to recover from writing your thesis; you had a period of having absolutely no responsibility whatsoever!
DeVorkin: Was your period of writing and working on the thesis a period that you look back at as a high-pressure period?
Newkirk: Yes, it was very stressful, and it was done under the pressure of the draft board chasing me; and then I also had the added pressure of the break-up of my first marriage. So, all of that was going simultaneously. In a certain sense, being in the Army at that period of my life was not all that bad.
DeVorkin: Were you married to anyone we should talk about in your first marriage?
Newkirk: Well, it was a gal I had met at Harvard, who was also, at least for a period of time, in astronomy. Her maiden name was Joyce Marrison.
DeVorkin: She was in astronomy for awhile.
DeVorkin: When did she leave it?
Newkirk: I think about 1953, 1954.
DeVorkin: About the time of your break-up.
Newkirk: Yes. She was at Michigan, also.
DeVorkin: Did she complete her Ph.D.?
DeVorkin: What did she go into at that point?
Newkirk: I donít know.
DeVorkin: Well, it was obviously a stressful time for you; but now you were in the Signal Corps. And what was the atmosphere like there for doing research? Were people talking about real research interests? If this was the center for Army research, what were they really doing?
Newkirk: Well, the only scientific contact I really had there was with the meteorological group. And they had various scientific interests. Iím not sure whether it was because activity was classified, or whether — looking back on it, it was a civilian group that ran it — the people simply were no longer, or never were the most active scientists. There were a couple of them who were, but many of them were not. Ben Stroud was interested in rocket meteorological work, rocket winds, that sort of thing. But it wasnít the sort of scientific activity with weekly seminars or something else like that. There wasnít that much communication among the scientists.
DeVorkin: Okay. But you were aware of the fact that Ben Stroud was interested in rocket meteorology.
DeVorkin: Did you assist him or work with him at all on that?
Newkirk: No. Partly as a result of the fact that I was able to do my own reading, I got interested in the problem of scattering in the atmosphere of the earth — atmospheric optics. That was the initial contact that finally led to the coronagraph business.
DeVorkin: I see. So thatís where you date the interest from, not necessarily from Menzel or earlier.
Newkirk: Well, Menzel was interested in coronal observations, and there was the classical Lyot coronagraph work, which I knew about. But I had not engaged in any experimental work on the corona at all.
Newkirk: This work with the Signal Corps was straightforward atmospheric optics. What are the scattering properties of the atmosphere? For example, what are the scattering properties of the atmosphere for horizontal visibility? There was interest in that in the Signal Corps! It began to occur to me that the routine observations at, say, Sacramento Peak or at Climax, of measuring the brightness of the sky near the sun might be a rather interesting technique to find out about the atmosphere.
DeVorkin: Is this something you realized all on your own? Nobody was directing your research?
Newkirk: No, I canít remember that anybody directed me. I would ask questions, and they had some scattering experiments for measuring horizontal visibility. I would ask about it; and they would say, maybe you ought to go talk to so-and-so, or read this, so you can find out whatís going on in the whole field. I knew I couldnít do straightforward astronomy there, but I wanted to do something that was interesting. I was encouraged to put something together on my own. It was a place of fairly free inquiry.
And thatís when, given that idea, I began to correspond with Jack Evans and with Walt Roberts.
DeVorkin: People you already knew.
Newkirk: People I already knew. Asking about whether they knew whether anything like this had ever been done, and could one make some interpretation of the scattering properties of the atmosphere. The more I looked at it, the more I talked to people, the more intriguing it became, because we realized that there had been some experiments along these lines done in Germany just before, and during the war, amazingly enough, of exploring the size distribution of particles in the atmosphere and their variation with height, from an aircraft.
DeVorkin: Yes, thatís right.
Newkirk: It was an amazing thing. Just as an aside, they carried those damned experiments out until April, 1945. Itís a wonder they didnít get shot down.
DeVorkin: What military purpose could that have had, other than horizontal visibility?
Newkirk: I canít think of any. I canít think of why they let their people fly around (laughs). They were using good military aircraft for measuring the attenuation of the atmosphere as a function of height. I think the only thing it could have to do with the military is that from an aircraft it isnít just horizontal visibility, it is visibility in every direction. Thatís the solid aspect of the military problem, so far as they were concerned. The instrument which I used was the direct progenitor of the device downstairs, the FDVU or the ATM Coronagraph. It was in fact the externally occulted coronagraph that Jack Evans built back in the late 1940ís as a device to measure the brightness of the sky near the sun as a control for coronagraphic observations.
DeVorkin: Oh really. So that is what youíre calling the sky photometer in your observations.
Newkirk: Thatís it. There were two reasons that they made the sky photometer. At Climax where coronal observations had been going on, by that time for several years, one of the limitations and one of the confusions was the light scattered in the atmosphere of the earth. Thatís the background against which one observes the corona. Itís extremely variable. And for the first few years during which the coronagraph was operated at Climax, they estimated the sky background visually by covering the disc of the sun with a thumb, and just making a guess at how bright the sky was.
DeVorkin: Did they do it qualitatively?
Newkirk: That was long before I was associated with the project.
DeVorkin: Well, do you know how they did it, such as, deep blue, light blue, milky.
Newkirk: Yes, that sort of thing.
DeVorkin: Oh, boy (laughs). Sure, thatís the seat of the pants.
Newkirk: Then Jack Evans came and decided that things could be done better than that. So the occulting disc on the end of a little boom in front of the lens was the first improvement on your thumb stuck up over the sun. They first made one out of plywood and a metal disc stuck on some sort of broomstick-like thing.
About the same time the effort to locate the site for the solar observatory was occurring, and they realized that they wanted to do site-survey work of the sky brightness at different locations. So a fair number — I would guess half a dozen — of a considerably improved engineering version of this visual sky photometer were made. And it was still a visual instrument, but it was quantitative. You could see a standard field, the brightness of which you could vary by pushing a wedge back and forth, and you could see the sky immediately around the sun. You could move the wedge to the point where the two fields balanced, and there was your sky measurement.
DeVorkin: I understand, okay.
Newkirk: About half a dozen of those visual photometers were built with the original intention of passing them out to ranchersí wives and other people who were living off in remote areas. In that way you could get an idea of where the good places were in the Southwest United States. And thatís this device in this picture.
DeVorkin: Oh, okay now. Youíre showing me a small device leaning on a rock, and who is this person?
Newkirk: Thatís Jack Evans.
DeVorkin: Thatís Jack Evans using it. Thatís a historic picture.
DeVorkin: Is there a date on here? Yes, 1948, 20th of March, Death Valley, Augerbury Point. Thatís very nice.
Newkirk: Jack Evans then became interested in the problem of how skylight varied with altitude and location. And so he made some experiments, this one being Death Valley. He went up on a few mountain tops actually. Didnít I send you that one reprint of his where he made observations from an aircraft?
DeVorkin: It does not ring a bell. Michael may still have some of that. The reprint from Jack Evans is on the photometer for measuring the sky brightness near the sun. And I donít recall seeing anything about an aircraft in here. It talks about the HAO photometer. He has a schematic on page 1084.
Newkirk: Yes, thatís it.
DeVorkin: The sky photometer.
Newkirk: Thatís it.
DeVorkin: But nothing about an aircraft.
Newkirk: Maybe itís just referred to in the other one of mine. There was a mimeographed reprint of mine that I sent you, and that was probably just referred to there. I may not have sent you the aircraft one.
DeVorkin: Iím wondering. Iíll put this on hold.
Okay, Iíll indicate we are recording again. This is after lunch, and you are still at the Signal Corps.
Newkirk: I guess there is one misconception which we shouldnít let creep into this. We shouldnít underestimate the value of the development of the Lyot Coronagraph. The whole question of observing the corona outside of eclipse had fascinated people for, well, a hundred years prior to the successful operation of the Lyot Coronagraph. It involved quite a few people, among others, George Ellery Hale, who interestingly enough tried to make a coronagraph. He carried it up the side of Mt. Aetna, and sulfur fumes ruined the surface of his mirrors! There were a variety of different, sometimes ingenious, attempts, to make observations of the corona outside of eclipse.
Then in the late 1920ís Lyot was successful, and it is worthwhile, as a point of background, to see why Lyot was successful. He was very systematic in analyzing what the sources of scattered light were that prevented prior attempts from being successful. Another aspect that I think gave him an advantage which the others didnít have. About that time there were actual quantitative measurements of how bright the corona was. Prior to that, people knew that the corona was much fainter than the disk of the sun; but whether, it was a millionth or one ten-millionth, or one five-hundred-thousandth, or whatever, nobody knew. Since that information had become available, he knew quantitatively the problem he had to overcome. He had to get up high in the atmosphere to reduce the atmospheric scattering, and then he very systematically proceeded to reduce the scattered light in a telescope.
DeVorkin: He used a single-element lens?
Newkirk: He used a single-element lens and an internal occulting disk to block out the image of the sun. The part that really made the difference was a field lens which formed an image of the first objective on an aperture, so that the diffracted light around the aperture of the objective could be reduced.
DeVorkin: Oh, this is a special filter, I take it.
Newkirk: Itís an apodization. If you were a bug sitting just above the occulting disk, looking at the objective lens, what would you see? The brightest thing you would see would be a bright ring of light at the edge of the objective lens which is the diffracted light. It is there simply because the aperture of the objective lens has interrupted the plane parallel wave train and diffracted the light. And what Lyot did was to eliminate that by putting a lens behind the occulting disk, and forming an image of the objective lens on an aperture, smaller than the image of the objective so that at least a major part of that ring of scattered light could be blocked. Behind that he put another lens to finally form an image.
Newkirk: The end result was an instrument which had a scattered light level of the order of one-millionth the brightness of the disk of the sun. Thatís more than adequate for terrestrial observations, because even on the best mountain sites in the visible region of the spectrum, the scattered light from the atmosphere is usually in the range of, oh, maybe six to ten-millionths. So that was perfectly adequate for the inner corona.
Now the observations which were made until, say, the early 1960ís, of the corona, outside of eclipse, were of two types. In one, observations of the emission lines in the corona gain an advantage because the radiation from the corona is concentrated into a single line. The second is the advantage of using the fact that the radiation scattered from the electron corona is highly polarized, while the light near the sun in the sky is weakly polarized, and the polarization angle is much different from that of the corona. The study of the emission line corona allows you to go out only to about a third of a radius above the limb. Using the polarization, you can get out to one and one-half radii, sometimes two radii from the limb. We are still using that technique in Hawaii, because it does give us the bulk of the corona. That one-millionth scattered light level of the Lyot coronagraph is about the average brightness of the low corona in the continuum. If you are going to get the outer corona, and by outer corona, I mean three, four, five, six solar radii, you are dealing with brightnesses which drop to 10-9 to 10-10 of the disk of the sun. So you have to accomplish an improvement in the Lyot coronagraph, a reduction of the scattered light level in the Lyot coronagraph by about four orders of magnitude. Thatís the technical aspect of the problem.
DeVorkin: Right. Now, Jack Evansí externally occulting device, was that designed to begin a stab at reducing the scattered light?
Newkirk: You can ask Jack Evans, but I donít think he really ever considered that device as a progenitor of a whole generation of coronagraphs. He had a very specific problem to solve, which was to make a quantitative measure of the sky brightness.
DeVorkin: The sky brightness, yes. So using these things on spacecraft and rocket sondes and balloons is something he didnít have in mind.
Newkirk: I donít think he had that in mind when he first designed the instrument. As a piece of technical background, we may want to work this in at a later time, the Evans sky photometer scattered light level turns out to be something like 10-7.
DeVorkin: So itís a little better, yes.
Newkirk: Thatís an improvement of about 10 in the Lyot coronagraph. The further improvement which had to be made to finally realize something like the ATM coronagraph was like three orders of magnitude.
DeVorkin: Could we break here and go downstairs?
DeVorkin: They said theyíd be waiting for us. Terribly sorry to break all this up, but we will take a pause now.
Okay, we are recording again. We had just finished in the last taping here, talking about the improvement in reducing scattered light by several orders of magnitude. But you said that the external occulting disk still had three orders of magnitude to go.
DeVorkin: Now, in your work at HAO, is it correct to say that it was devoted toward reducing that degree of scattered light with space in mind?
Newkirk: By the time we got to that stage, yes. I just wanted to fill that in as a technical aside to put in context as to what the technical challenges were in each stage, but we were talking about the chronology of where and how this all got started, with the sky photometers.
Newkirk: Jack Evans made these visual sky photometers for site survey work and for on-site measurements of the sky brightness, to correct the emission line coronal observations which were made at Climax, starting in 1940 and at Sacramento Peak starting, I guess about 1948. Jack had become interested, as you can see from this photograph, and you can keep that, by the way -Ė
DeVorkin: Oh good! Thanks.
Newkirk: You can make a copy of it, because I just dug it out of old stuff we had at HAO.
DeVorkin: Certainly, we will make a copy of it for the record, and it will be a part of your interview.
Newkirk: He became interested in that aspect of the problem, scattered light in the atmosphere, making observations of, still with the idea that this was a principal impediment to, and understanding the corona. An improved version of that hand-held visual sky photometer was made, which used photographic recording. His plan was to fly that instrument in an aircraft, make surveys in different parts of the United States, and make surveys as a function of altitude. One of those instruments was built under an Air Force contract to HAO back in the late 1940ís. However, he then took on the responsibility of Sacramento Peak Observatory. And the project was dropped. In my correspondence with him when I was back at the Signal Corps, he said ďthere are not only the visual sky photometers but thereís also the photographic device. If you are really interested in measuring sky brightness, why donít you find out where that is?Ē Well, we found out where it was. It was squirreled away in some storeroom in HAO. So then I started talking fast back at Signal Corps.
DeVorkin: To whom did you talk?
Newkirk: To the civilian supervisors there.
DeVorkin: And they were scientists themselves?
Newkirk: They were scientists. I had to convince them that this was a good project and that they should put me on detached duty to go out to Colorado to carry it out. I guess they correctly identified this as also a means of getting out of Fort Monmouth (laugh). There was an ulterior motive in it, but it was also scientific curiosity. In the fall of 1954 I went out to Boulder and spent from the fall of 1954 until the spring of 1955, putting that instrument in shape and then making observations at several different levels in the atmosphere.
DeVorkin: Up and down the mountains?
Newkirk: Up and down mountains, starting in Boulder and then moving up. For a Ph.D. corporal this was the greatest of detached duties, because the final place where I took it was at the top of the Arapahoe Basin Ski Lift, and when it was cloudy, why there was nothing to do but ski. So I learned how to ski, also.
It was also scientifically successful, because it did lead to some of the earliest quantitative measurements of the angular distribution of skylight very close to the sun, which is the part which is most easily interpretable in terms of the size distribution of the particles that are scattering the light. Of course, there is the scattered light which is produced by the molecules, the so-called Rayleigh scattering. Thatís very well known. But the scattered light produced by the particles is an entirely different sort of thing. Well, the observational part was carried on from December through February, and the rest of the time that I was back in Fort Monmouth until I was mustered out, I spent in the interpretation of those observations.
DeVorkin: Yes. This led to this paper.
Newkirk: Thatís the Signal Corps report. Yes, that blue thing.
DeVorkin: ďThe Solar AureoleĒ it is called. Is that a standard term?
Newkirk: Yes. It is the same word as the aureole that surrounds saintsí heads in religious photographs.
Well, then I mustered out and prior to that I had been offered a job at HAO, as well as a job at Sacramento Peak.
DeVorkin: By the respective directors?
Newkirk: By Jack Evans at Sac Peak, since I had been there, I could have had my old job back, in a certain sense. And by Walt Roberts at HAO. And I decided that, well, so far as I could see, the scientific opportunities in the two places were about the same, but the personal opportunities in a town like Boulder were entirely different than those on the top of the mountain at Sacramento Peak, which is really very isolated. So that influenced my decision.
DeVorkin: I can understand that.
Before we turn to that, let me just ask you: Why did you publish this particular paper, Photometry of the Solar Aureole in the Journal for the Optical Society of America, and not in, letís say, an astronomical type journal, even the PASP, or something?
Newkirk: Well, thatís a topic for which most astronomical journals wouldnít reach the readership. Such questions as the optical properties of the atmosphere would be published in the Journal of the Optical Society.
DeVorkin: Did you find that you were reading the Journal of the Optical Society of America more than you were the APJ, so to speak?
Newkirk: Oh, I donít think so, but it was just the appropriate place for the article.
So I went out to HAO. I got involved in several projects there, some of which had nothing to do with this general line of work. One project I was involved in was with Gerard Wlerick who was a visiting French astronomer. He undertook most of the effort of the development of a coronagraph, using the fact that the scattered light from the electron corona is polarized to separate out the signal from the corona from that of the sky. And as I say, he took on the lionís share, 99% of the share of the development of the instrument, but then I took on the major part of the observing and interpretation of the observations with that instrument. That was the point that finally got me intensely interested in the corona. I hadnít really paid much attention to problems of the corona prior to that.
DeVorkin: Your first publication on the corona itself is 1957, ďDoppler Motions in the Corona.Ē Was this part of that?
Newkirk: Oh no, that was another side issue of using some of the emission line observations of the corona.
DeVorkin: Okay, yes, you mentioned that.
Newkirk: And that continued.
DeVorkin: All of this was ground based.
Newkirk: All of this was ground based.
DeVorkin: There was no interest at all in balloon work at that time?
Newkirk: No, we still had this photographic sky photometer, however. It didnít seem worthwhile to pursue any further the sort of observations which I carried out in the Army. About that time, about in 1957, I had been at HAO about a year and a half.
Newkirk: And I canít remember exactly what the circumstances were. Well, I do know what the connection was. Some of the research that we were doing was sponsored by ONR. We were introduced to Malcolm Ross who was a Navy captain and interested in ballooning.
DeVorkin: And this was through the ONR?
Newkirk: Yes, and I guess that he had been sent out to visit the contractors in the provinces.
DeVorkin: Who was your major ONR contact?
Newkirk: The contractor monitor at that time was Harold Glaser.
DeVorkin: Harold Glaser. He worked in ONR?
Newkirk: Yes, he worked in ONR. He worked later in NASA, and then NSF.
DeVorkin: I see the connection. Okay, itís a very obvious one.
Newkirk: We began to think that it would be worthwhile to refurbish the effort of measuring sky brightness, determining what the sky brightness variation was with altitude, only instead of an aircraft, use a balloon. We now had Ross interested in the ballooning aspects. The idea sort of lay fallow for a year or so.
DeVorkin: Well after Sputnik then? October 1957?
Newkirk: Yes, through that period. There were informal conversations throughout that whole period, and I canít identify just what happened.
DeVorkin: Can you remember any other people involved?
Newkirk: There was Walt Roberts and Mal Ross. Shirley Silverman was also involved in ONR. In 1958 we received a small amount of money for equipping this photographic sky photometer for operation in a manned balloon.
DeVorkin: This was through your contact with Malcolm Ross?
Newkirk: Through Malcolm Ross and Harold Glaser, and I canít remember just exactly how the thing was financed. It was to equip the instrument so it could be operated from a balloon. There were some financial difficulties at ONR, and they couldnít find money for a balloon. Things dragged on until the summer of 1959. I remember my wife and I were just about to come back here on a vacation when Mal Ross called up and said, ďWe have the money for a flight this summer.Ē There was a mad scramble, and we ended up with the instrument in the Strato Bowl in South Dakota.
DeVorkin: Strato Bowl; what is that?
Newkirk: Itís a large natural bowl in the ground. Itís where the Anderson stratospheric balloon flights in the 1930ís were carried out.
DeVorkin: What did they call them, Explorer 2, Explorer 1?
Newkirk: I canít recall what the names of the flights were. They were big rubber balloons.
DeVorkin: Yes, those are the famous ones.
DeVorkin: Let me turn the tape over.
Newkirk: And so my wife and I, after coming back East and visiting, ended up in the Strato Bowl. They brought the instrument up from Boulder and the gondola from Minneapolis, where it had been constructed. One of the HAO staff members had eagerly requested to be along on the balloon flight as the second crew member. The Navy decided that that was acceptable.
DeVorkin: Was the balloon flight considered that routine that they could send someone up?
Newkirk: I donít know what the official Navy attitude toward manned balloon flights was, but this Bob Cooper had been a crewmember on an aircraft during the war. So he did not have to go through the long period of high-altitude training. He just had to be re-educated. He was a design engineer at HAO.
DeVorkin: Was there any question in your mind as to the efficacy of manned ballooning? Did you think this could be done unmanned?
Newkirk: At that time there was the stratoscope flight that Schwarzschild was doing. But the whole effort to design and construct an unmanned gondola seemed to be a bit beyond our means. Schwarzschild had had only one successful flight at that time. His was considered as a very daring and pioneering venture, and we were just really starting out. I wasnít Martin Schwarzschild and I didnít have the reputation to bring in the money for an automatically guided gondola. I was a young punk just out of the Army.
DeVorkin: I see. So he was not only better established, but his work cost considerably more than yours did, even though yours was manned.
Newkirk: I donít know the overall cost. I think that at that time an unmanned balloon flight with all the engineering you had to put into the initial development of a pointed gondola was far above what was available for a manned balloon flight.
And, well, that flight was carried out to, I guess, 40,000 feet. It was a qualified success, qualified meaning something like 10%. We were beginning to learn the hard way about the advantages of careful environmental testing of your experiment. We had it all prepared and sent it off with the two of them in the balloon, and up it went. Their plan was to go up to 40,000 feet and during the descent to make the observations with the sky photometer.
DeVorkin: This would be a balloon descent?
Newkirk: Balloon descent, yes, a slow descent from 40,000 feet.
DeVorkin: In order to do that, they had to get rid of the gas, right?
Newkirk: Youíve got to valve it off slowly.
DeVorkin: Wouldnít that cause a vaporous cloud?
Newkirk: No, the reason we did it on the descent was because you leave the debris from the balloon behind you, rather than ploughing through it. There are all sorts of junk, mostly talc sloughing off the balloon, and that would be drifting down in front of us on the way up. We had thought that one out. But there was another aspect of it we hadnít thought of. That was that the battery box to run our instrument was put on the shady side of the gondola, and it froze. It had enough charge to run about a dozen exposures through the sky photometer, and then it quit. We had the top heights which were the most valuable, but the rest of it was lost.
DeVorkin: Did your people know it when it quit?
Newkirk: They had a suspicion but they werenít sure.
DeVorkin: I say that must have been a bit of anxiety.
Newkirk: We werenít in radio contact with them. So we didnít know until they got down. Cooper said, ďIím not sure everything came off all right, whether it came through.Ē
So, we picked the gondola up and picked the instrument up and developed the film. We had some good observations. About that same time Schwarzschild decided that he had done all the worthwhile work with the Stratoscope 1. He called up and said, ďdo you want the gondola?Ē
DeVorkin: So he offered it to you unbidden?
Newkirk: He offered it to us unbidden.
DeVorkin: Thatís lovely.
Newkirk: Well, thatís the sort of guy he is (laughs), and we didnít need another invitation, I said yes right then and there. We got back from Rapid City, South Dakota something like the middle of August, and he called us up in September 1959 and sent us the gondola. No, pardon me. Thatís not quite correct. He had decided to offer the automatically guided gondola at the same time we were flying from South Dakota. Thatís right. Thatís what happened. And he called HAO in Boulder, and Walt Roberts called me in South Dakota and said that Schwarzschild had offered the Stratoscope gondola, what should he say? I said, say, yes, and call him back now (chuckles).
DeVorkin: Had Jack Eddy already worked with Schwarzschild yet?
Newkirk: No. I asked Walt how we were going to do this, just finding the manpower? Walt suggested, remember, weíve got this graduate student, Jack Eddy. How about his being involved in it? And I said, that sounds great. Why donít we send Jack Eddy off to Minneapolis to work with Schwarzschild on the last flight? And so, thatís what was done. In August of 1959, I had to come back here to Washington to give a scientific debriefing for ONR on the scientific results of the flight.
DeVorkin: Is this common practice to come to Washington for a debriefing?
Newkirk: It was then, yes. It was the Navy way of doing things, I guess.
DeVorkin: To your recollection, was it transcribed or recorded by a stenographer or tape recorder?
Newkirk: I just canít remember at all.
DeVorkin: Okay. But it was definitely an ONR debriefing. Who was the cognizant person in the debriefing process? It wasnít Glaser, was it?
Newkirk: Yes, I think it might have been, that is, from the ONR end, but from the operational Navy end, I donít remember. It was a combination of ONR and Navy operations, one of those complicated deals. On the way back to Boulder, I went to Minneapolis and stayed several days watching the Schwarzschild operation. Jack Eddy had already been there a couple of weeks. This was in preparation for Schwarzschildís last flight of Stratoscope 1. I saw their preparations, and Jack stayed through the flight. I think we also sent our electronic engineer, who was Robert Lee. I think I remember his going back to work with Schwarzschild on the final flight as well. Schwarzschild was very happy to do this, because it gave them relief from their rather tight manpower situation.
That picture of the tent: I donít know where that tent was, because they had the gondola in a sparrow- infested hangar with bird droppings and all when I visited.
DeVorkin: Thatís right.
For the tape, weíre referring to a picture of a tent housing for the gondola of Stratoscope 1 that is in gallery 111 right now.
Newkirk: In the fall we had the gondola and spent the fall, winter, and spring building up what we regarded as the definitive observational experiment for sky brightness at stratospheric altitudes.
DeVorkin: So it was still the sky photometer you were working on.
Newkirk: It was still the sky photometer. We knew the instrumentally scattered light level to be too high to allow us to detect the corona. But there was still the question of the sky brightness at balloon altitudes and what do you have to do to be able to detect the corona. We were still thinking in terms of balloons.
Newkirk: Well, we made all sorts of calibrations on the photometer itself. We added a device called the periscope which allowed us to see not only the sky within the first three degrees of the sun, but which also allowed us to pick off the sky at 10, 20, 30, 50, 60 degrees from the sun. We made a little spectrograph, which went into the instrument, and allowed us to determine the spectrum of the sky radiation close to the sun. We made another instrument which with high photometric precision made very frequent photoelectric observations sky radiance at some angle. I guess it was about 10 degrees. I canít remember what it was.
DeVorkin: So this was a multi-function instrument.
Newkirk: It was all to understand the skyís radiation.
DeVorkin: Right, but you had many different sensors and many different techniques. Were they all controlled independently from the ground by the TV system that Schwarzschild had used?
Newkirk: We did not take on the TV system. This was all remotely run by what now would be considered a very crude technique, a timing motor with a cam switch, which started various and sundry functions.
DeVorkin: But it still had to be pointed toward the sun.
Newkirk: It still had to be pointed toward the sun. And that was the job of the Schwarzschild gondola.
DeVorkin: The pointing controls on that gondola were Ball Brothers.
Newkirk: The pointing control was Ball Brothers. The original design for that thing was made by Russ Nidey.
DeVorkin: Thatís right, the man I would like very much to talk to.
Newkirk: He is no longer in Tucson. Where the dickens is he now?
DeVorkin: Thatís what I found out, but havenít been able to find him.
Newkirk: Heís somewhere down in Arizona.
DeVorkin: So heís not in Boulder.
Newkirk: No. Thatís probably the most successful balloon gondola design thatís ever been made, because it has a bird cage structure which protects your instrument. There have been several others made and they have not used that design. The instruments get bashed up on landing. Itís always going to land!
DeVorkin: Thatís right.
Newkirk: The idea of this precision photometry was to make observations in a single wavelength at a relatively close angle to the sun, but very, very frequently in time, because we wanted to get as much detail about the height profile of scattering as we could. The photographic observations, particularly the spectroscopic observations, would require 30 seconds or a minute per exposure at those altitudes, we had calculated. We were planning to have a very slow descent on the balloon. But even then the balloon would descend maybe 300 to 1,000 feet during an exposure. We wanted to find out if there was any fine scale stratification. By that time we were taken over by almost unbridled scientific curiosity about the sky radiation scattering itself, and the idea of the coronal problem was somewhere in the back of our minds, and quite subdued. We really had the accelerator to the floor on sky brightness business. We had to learn to use the stratoscope gondola and made some modifications. Then the following summer, 1960, we packed the whole thing off to Minneapolis. General Mills was doing the operations for us. Funding was still from ONR. So they were paying for the balloon and for this experiment contract. I think there was also NASA funding. There was, because I remember coming back here with Walt Roberts, I think, in the spring of 1960, visiting some of the very early people in NASA. They were in a rented house somewhere over on the other side of the Capitol. It was an old apartment house. Thatís where NASA was then. That was it. That was NASA.
DeVorkin: Was it Naugle?
Newkirk: John Naugle.
DeVorkin: Homer Newell, possibly?
Newkirk: Homer, yes. And they were all there. Thatís right. I forgot about it. So there was NASA funding in it, as well.
DeVorkin: Itís about the time that Nancy Roman came in.
Newkirk: She was there, yes. I knew her from before.
DeVorkin: In your work on sky brightness, you were finding that the Navy was interested in such a thing. What was NASAís interest?
Newkirk: I canít remember how we explained it to them (laughs). I just donít know.
DeVorkin: You had various papers here, ďGeophysical Researches with the Stratospheric Laboratory.Ē That was 1959. ďApplications of Manned Stratospheric Laboratories.Ē ďMinutes of Sessions Held at 27th Annual Meeting of Institute of Aeronautical Sciences. That was January, 1959.
DeVorkin: So this was before you actually used Schwarzschildís gondola. So what you are referring to here is your original manned balloon.
Newkirk: Also to the plans for manned experiment, too.
DeVorkin: Yes. Are there any transcripts of these minutes of sessions because we couldnít figure out how to find them.
Newkirk: I just donít remember whether there are or not. We didnít publish any paper. I remember we did take some of the earlier observations — that was before we even had the manned balloon flight — that I had from the mountaintops, take Jack Evansí aircraft observations, and make predictions as to what you might expect at balloon-accessible altitudes.
DeVorkin: You were also publishing papers with Curtis, Watson, Manning and Shelby on the inner solar corona. ďBackscattered Cosmic Rays by the Sunís Ionized Helium Sphere.Ē In all of these, were these ground- based observations?
Newkirk: The one on the corona was. The other one was on backscattering, just an idea that several of us had.
DeVorkin: Okay, so you were working on a good number of fronts at once?
Newkirk: Yes, as a matter of fact, that one was stimulated by Van Allenís coming out to HAO as an expert reviewer of the whole observatory. And he didnít do much formal reviewing. He sat around and talked to people and we chewed the fat and came up with ideas and things to think about.
DeVorkin: Backscattering of cosmic rays. Thatís marvelous. Iíll have to look at that.
Newkirk: Itís probably the most unreferred-to paper Iíve ever written (laughs). I donít think it has ever been referenced.
DeVorkin: Yes, itís an interesting title.
Well, things were developing. You had the Schwarzschild gondola.
Newkirk: We had the gondola. We were in Minneapolis. We spent approximately a month in the summer of 1960 in the detailed preparation for flight. This included tuning up the guider, testing the various timing circuits which, for example, told the gondola to point at the sun, told the coronagraph to unstow itself, told the camera to start — all that sort of thing.
DeVorkin: But those were just timing circuits. You had no control from the ground once it was launched. Why didnít you go with electronic controls?
Newkirk: Because they were considered to be unreliable then.
Telemetry was just not that reliable then. But something that ran like a washing machine timer (laughs), that was something you could really get your hands on.
DeVorkin: Thatís great.
Newkirk: And it was unreliable because if the balloon got further than 150 miles, you lost contact with it, unless you had a very fast mobile system. You had a good chance of losing control.
Well, one of the first movies here is of the first flight which was a disaster. It was launched in a cross wind, and the balloon pulled the gondola and the launch truck over. The gondola ended up on the runway and the batteries fell off. It is a spectacular movie. You would really enjoy it.
DeVorkin: By the way, can you estimate the total length of the movies, so that we know that we are planning correctly? Iíll put it on pause.
Newkirk: Or we could go down a little bit earlier.
DeVorkin: That would be fine. But I want at least to begin talking about the Coronascope.
DeVorkin: The one we are talking about is not Coronascope I, I take it.
Newkirk: Yes, thatís what we christened it then. Coronascope I was this battery of sky radiance measurements.
DeVorkin: Very good.
Newkirk: After that disaster we were very lucky that we retrieved the gondola. Because of the very fine design of the gondola itself, the instrument, the coronagraph itself, and the subsidiary instruments were not harmed at all. There was damage to the battery boxes, and the frame of the gondola, which was a bit twisted up. That was it. That was in the early part or middle of August. Two or three weeks later we were ready to fly a second flight in early September of 1960.
DeVorkin: Did you take that all from Minneapolis back to Boulder to fly?
Newkirk: No, we did it in Minneapolis. Jack Eddy was in on that. We had a successful flight in the middle part of September, and retrieved the gondola. We had another flight the first part of October, and so we had two flights under our belt. We spent the whole next two years plus, analyzing and interpreting the data. The things we found out were first the obvious numbers of what the sky brightness was as a function of altitude and wavelength, which very early convinced us that coronal observation from stratospheric altitudes in the near infrared, the photographic infrared, was perfectly feasible. And there were all sorts of atmospheric science results.
DeVorkin: This whole thing was not, as you said before, envisioned as a feasibility study?
Newkirk: It didnít start out that way, but it evolved that way fairly fast.
DeVorkin: Okay. That saw the astronomer coming back out in you?
Newkirk: Yes. In these minutes that are probably never going to be found, one of the things that was pointed out at the New York Academy of Science sessions was that if our predictions are true, you can in fact observe the corona.
DeVorkin: Yes. So this was the New York Academy of Sciences, this Institute of Aeronautical Sciences 27th Annual Meeting. Iíll bet I could find that.
Newkirk: I bet you could, if they kept it. But that was just one of the things, not just the atmospheric sciences, but the astronomical possibilities as well. There were some atmospheric science that came out of it as well, because we had very detailed observations of the concentration of aerosols in the stratosphere. This was not what you would call a discovery item, but it was certainly a confirmatory item. Junge, the German atmospheric chemist, had been making stratospheric sampling flights and had discovered — or maybe not even say discovered — had confirmed that there was indeed a rather concentrated layer of aerosols in the stratosphere up in the 20 kilometer altitude range. And we saw the same thing. We also saw some things which he had not observed. One was that it was very, very finely striated. The other thing was that the vertical concentration profile could not be interpreted except with the additional assumption that micrometeoritic material was contributing to this by raining down from above. Thatís how we got in contact with the people who were doing micrometeor work.
DeVorkin: Yes, was that Hemenway at that time?
Newkirk: That was Hemenway and several other people whose names I canít remember now.
DeVorkin: I know they had an early program at the Dudley Observatory.
Newkirk: Right, and they flew aircraft and balloons and rockets — the whole bit.
Well, as I say, the analysis of that took us through more than a year. There was a lot of data and a lot of work. About the time that that ended we started saying, okay, it is feasible to make coronal observations from stratospheric altitudes so far as the brightness of the sky is concerned, if you go into the near infrared. But youíve also got to carry out a substantial improvement in the scattered light in the coronagraph by three orders of magnitude.
DeVorkin: Yes, this is a substantial improvement in the sky brightness photometer that you had been using, or are you saying in the overall design of coronagraphs as well?
Newkirk: Well, if you started from the Lyot coronagraph, you had four orders of magnitude to go. If you started from the Evans sky photometer coronagraph, the first of the externally occulted type, you had three orders of magnitude to go.
DeVorkin: Okay, you had three orders of magnitude.
Newkirk: So work went on for, I donít know, a year or more than a year, in which we systematically went through the various sources of scattered light in the coronagraph to try to eliminate them. We started with the body scattering in the objective lens. Given a single objective lens, are there materials that you can make the lens out of which will scatter less light than just an ordinary piece of glass? We investigated all sorts of crystalline lenses and things like that, actually making little coronagraphs in the laboratory and measuring the scattered light from various crystals. It turns out that most crystals are worse than most glasses. Finally, the best material we could find, as a matter of fact, was fused quartz. It also had the desirable characteristic that it was hard. It didnít scratch. The other source — the most serious one — is the diffracted light from the occulting disk itself. The obvious solution to that was you put another occulting disk behind it. When one looks into the optics of this, one recognizes what one is doing is apodizing the occulting disk, making the edge fuzzy or, to put it another way, one is gradually reducing the contribution of the various Fresnel zones surrounding the occulting disk. We tried various experimental techniques with various numbers of occulting disks all the way to something like 50 of them in a line.
At the same time that this was going on the NRL people were beginning to explore this. Koomen and Tousey came up with the idea of the toothed wheel occulting disk.
DeVorkin: Do you know if that was Koomenís idea, or Touseyís idea?
Newkirk: I donít know. Tousey talked about it, but just because Tousey talked about it doesnít say that it was his original idea. He was the boss, and he ran a tight ship.
DeVorkin: Yes, thatís it. Did you know Tousey by that time?
Newkirk: Yes, because he heard of our plans during this period of 1961 to 1963 to really improve the coronagraph per Se. He said, during a visit out there for something else, ďYou know, it would be nice to make a collaborative venture.Ē
DeVorkin: Tousey suggested this?
Newkirk: I was a little bit afraid of that.
DeVorkin: Why so?
Newkirk: I had seen Tousey, letís say, aggressively pushing his own, position (laughs) at the expense of some of the people who worked for him, quite honestly. Again, I was still a very, very junior person, and I didnít want to be under Touseyís shadow. Letís put it that way.
DeVorkin: Did you feel that there was a relative value to the sawtoothed occulting disk as opposed to your multi-disks?
Newkirk: Yes, we argued about it for a short time, because I didnít understand how his idea was in fact going to work. I finally convinced myself by trying one in the laboratory. Then I realized that, so far as the physics were concerned, they were basically equivalent. We actually tried using toothed wheels in the laboratory, and found that, at least with the techniques that we had available, we couldnít make the toothed wheel regular enough and keep it clean enough to reach the equivalent performance of the multiple occulting disk. It was a practical choice. He was at that point racing to make a coronagraph for one of the OSOs.
DeVorkin: Yes, he was doing that, but at the same time they did fly that coronagraph on Aerobees, in 1962, 1963.
Newkirk: They flew that coronagraph on a rocket, too. I think the first Aerobee flight with the coronagraph was the summer of 1963.
DeVorkin: There seemed to be quite a bit of competition, at least, as I sense it, to be the first to get out to x-solar radii.
Newkirk: Yes, there was at this time. There was, indeed. It developed after he had asked, should we make this a cooperative venture, and I had said, no. Tousey flew a rocket in June or July of 1963. We were then in the business of putting our instrument together.
DeVorkin: This is Coronascope II now?
Newkirk: Right. Testing it. In August of that year we took the whole shootiní match down to Kitt Peak where they had a big vacuum tunnel, and set the instrument in the vacuum tunnel to evaluate the scattered light in the coronagraph. By that time Dave Bohlin was involved.
DeVorkin: Was David Bohlin a graduate student?
Newkirk: Yes. Bohlin is now at NASA Headquarters. All through the fall we did preparations on that guiding system. We were trying to squeak 5 seconds of arc guiding out of that old gondola, and it was built for one minute of arc. We were worrying about scattered light off the gondola into the coronagraph, and all sorts of things like that. The following February we left Boulder with the gondola and coronagraph for Palestine, Texas where the scientific balloon facility had been established by NCAR.
DeVorkin: Well, we havenít talked at all about HAO and NCAR, but thatís a different story.
Newkirk: Yes, and Walt Roberts is the person to ask about HAO-NCAR, because he was the founder of both. And interestingly enough, we had not seen any of Touseyís supposed rocket observations.
DeVorkin: What do you mean supposed?
Newkirk: Iíll explain that in a minute (laughs).
DeVorkin: Please do.
Newkirk: The competition was high; and there was the possibility of even greater competition for a coronagraph aboard what was later to become the Advanced Orbiting Solar Observatory.
DeVorkin: The AOSO.
Newkirk: The AOSO was already being talked about, and the opportunity to build a coronagraph on that was beginning to emerge. We were running fast.
DeVorkin: Through whom did you hear about AOSO?
Newkirk: Through the usual channels of requests for proposals. Jack Eddy had come back to HAO to work on the planning for a coronagraph for AOSO.
DeVorkin: This was 1963.
Newkirk: This was, no, January 1964 by this time. I canít remember when Jack Eddy really first came back.
DeVorkin: Sure, we can get that.
Newkirk: We were down in Palestine, Texas and we had transformed the instrument so it was operating in the near infrared. We had convinced ourselves that we had achieved that three orders of magnitude improvement in the scattered light level from our tests in the tunnel at Kitt Peak.
DeVorkin: So this is with the Multiple Occulting Disk?
Newkirk: A multiple disk, near infrared, two-inch aperture coronagraph. It had some real angular resolution so that you could see something in the corona. In March of 1964 we flew it. At the same time the AOSO proposal evaluation process had already started. At that time you proposed and then the principal investigator, or the representative of the principal investigator, went to be interviewed. I remember this very vividly, because it looked like a planned theatrical event, except that it was sheer dumb accident. They had the interviews at Cape Kennedy for the candidate experiments for AOSO. Jack Eddy went off to present our case. This was in March of 1964. And in March of 1964 we were ready for flight. The weather cleared up and we flew.
DeVorkin: Coronascope II.
Newkirk: The first flight of Coronascope II. And we came back with 50 feet of film and 50 feet of the corona on it. So I called Jack Eddy at Cape Kennedy and said we have the corona. There it is, no question. And Jack Eddy announced this at the damned meeting (chuckles). It was the same size as the coronagraph which finally flew in the ATM but on a balloon gondola.
DeVorkin: On Schwarzschildís gondola.
Newkirk: On Schwarzschildís gondola, and there was the corona! There was no doubt that it was the corona, because it was an altazimuth mount and during the day you could see the corona rotate like this. So that was really exciting. There it was. As we pulled the film off under the drying rack, you just had to look at it, and you could see, there it was, and you could see it rotating. That was the origin of that cartoon.
DeVorkin: The Snoopy cartoon.
Newkirk: The Snoopy cartoon.
DeVorkin: It says: ďHappiness is the corona to 4 radii on the first try.
DeVorkin: Who dreamt that one up?
Newkirk: That was Dave Bohlin. And that was it. We flew the instrument the following year for two other flights to squeeze some science out of it, too. To impress the readership of the Astrophysical Journal as well as of the Sky and Telescope. Dave Bohlin got his thesis out of the evaluation of the temporal changes in the outer corona over a period of a month and a half. We had an eclipse and then two balloon flights. That was the end of the saga of the balloon coronagraph. I should explain the untoward remark of the supposed corona.
DeVorkin: Yes. Now I know that about this time from the OSO coronagraph Richard Tousey was talking about, and also from the Aerobees, the corona out to 10 solar radii. Is this what you were referring to?
Newkirk: No. The point was this: By the summer of 1965 Tousey had a coronagraph aboard one of the OSOs and it didnít work. Then the second OSO coronagraph worked. That worked fine. But there had been a competition to see who got the outer corona first. It may be somewhat trivial.
DeVorkin: Was that competition to prove your technical mettle, to be able to then get the contract for AOSO.
Newkirk: Being first would not hurt the AOSO; but the race was just to be the first.
DeVorkin: What happened with the AOSO proposal? Did you get it?
Newkirk: We got it, yes.
DeVorkin: And what you had built for that was Coronascope II, or the evolution of that?
Newkirk: Coronascope II and what we built for AOSO were almost identical and very similar to what flew on the ATM. But in that stack of reprints — have you got the reprints?
Newkirk: Okay, Iíll show you the supposed business.
DeVorkin: Okay, good. Is this in Touseyís article?
DeVorkin: Okay, I can find it probably pretty quickly.
Newkirk: Well, we both went to the Liege Symposium, both with our birds in each of our bags, to amaze the world and set everyone gasping about how clever we were to observe the corona first. It was a friendly competition, but still there was no doubt that it was a competition.
DeVorkin: Hereís Touseyís article. ďObservations for White Light Corona by Rocket.Ē
Newkirk: Well, we had an observation, which you have probably seen. In fact some are really crummy pictures of the corona. I canít find my own. It was the Liege Symposium article. Didnít I send you the Liege Symposium article?
DeVorkin: This is the Analyses de Physique.
Newkirk: Thatís it. In the Tousey article, I claimed I couldnít see any corona. Yes, thatís a drawing. And thatís the real photograph.
DeVorkin: These are the real photographs, Figure 3.
Newkirk: Didnít I send you a copy of that?
DeVorkin: Yes. Itís in here.
Newkirk: Here was the bone of contention.
DeVorkin: He says, ďWith the artifacts removed by retouching,Ē and you circled it with an exclamation.
Newkirk: (laughs) And that was in my copy of the thing.
DeVorkin: What are you implying there?
Newkirk: Well, that in scientific discovery, one shouldnít retouch the photographs (laughs).
DeVorkin: Yes, here they are. Here are yours, in the photographs.
Newkirk: Yes, those were just prints, pulled directly from the films.
DeVorkin: Great. Very nice.
Newkirk: Okay, maybe if we are going to do those films, we ought to do them.
DeVorkin: Yes, itís a good idea. Itís a good place to stop, because at this point you begin building, or improving upon Coronascope II, which eventually led to ATM.
DeVorkin: We can talk about that next time when we meet.
One thing I wanted to clear up, though, your funding for the Coronascope II: was NASA taking over more and more of the funding?
Newkirk: NASA gave us a big shot in the arm in the funding for Coronascope II. In particular, I can remember they funded us for the balloon, and we were insisting that we wanted what was called a mylar scrim balloon, because we had a heavy payload which we wanted to take to what was then considered quite high altitudes. With the ordinary polyethylene film balloon there was some doubt that the probability of getting it to that altitude was any better than two out of three.
DeVorkin: That was above 80,000 feet.
Newkirk: Yes, we wanted to go to 30 kilometers.
DeVorkin: Thirty kilometers, yes. Well, letís break here then.
Newkirk: Sure, yes.
DeVorkin: And weíll just take that.
(They go to show the movies. End of Interview).
DeVorkin: I shall identify where we are. Weíre recording again in the Steenbeck Room. And what is the first movie you are going to look at?
Newkirk: Itís called: ďHow Not to Fly a BalloonĒ. (Movie begins).
These are some films which were given to us by a couple of the TV stations in Minneapolis. The TV stations had recorded the balloon flight. Thatís Malcolm Ross. Thereís the debacle.
This is the flight so-called, of our first unmanned balloon flight from Minneapolis in August of 1960. This is after we had redesigned the whole system to do everything that could be done, so far as observations of the sky brightness and the variation of the sky brightness with altitude. And this was the first attempted flight.
DeVorkin: August, 1960, with Schwarzschildís gondola.
Newkirk: This is with Schwarzschildís gondola. This is the launch. Thatís Malcolm Ross who was with us. And there goes the gondola.
DeVorkin: Oh my. Oh my. Oh god!
Newkirk: (laughs) And you can see why we were upset!
DeVorkin: Oh god! How did you retrieve it?
Newkirk: Well, it was released by a telemetry cutdown of the parachute from the balloon.
DeVorkin: Yes. So it went its whole route?
Newkirk: No, no, it only went about four miles away.
DeVorkin: Oh my gosh.
Newkirk: There it is being recovered in a dry lake, and you see why I said it was a good design, because the cage was rather banged up. But thatís about all. And then everybody comes out and picks up the plastic. These were just people who lived near where the gondola had landed. They saw it come down.
DeVorkin: Oh, itís awful. You must have felt terrible.
Newkirk: Now, this is another sequence of the same thing. That is Malcolm Ross on the left, one of the other Navy people in the middle whose name I canít remember, and myself. And in the background is the modified Schwarzschild gondola.
DeVorkin: Thatís still the old 12-inch gondola.
Newkirk: Thatís still the same gondola. We never modified the gondola frame.
DeVorkin: Yes, thatís interesting.
Newkirk: We tore the insides out and everything else, and welded new pieces on.
Okay now, hereís the launch. You can see the gondola. The crash pad is that white box on the bottom. This is a rather overexposed one, so you canít see anything happen until the photographer began to realize that something was going wrong. He heard screeching tires and people yelling.
DeVorkin: Oh god!
Newkirk: Thatís the second view (laughs).
DeVorkin: Well, you have plenty of documentation. Oh, thatís!
Newkirk: You might want to use this sort of thing just as a demonstration that everything doesnít always go just as planned. The early days of ballooning; we had another one like that, where we invited some Belgian people over, who wanted to get in the ballooning business, to see how it was done (laughs). We had a launch at Palestine like this.
DeVorkin: This is the truck again?
Newkirk: This is all the same scene. Three versions of the same mishap. Here is another one. Now, my recollection is that this last sequence is perhaps the best one. Oh, thatís just a picture of a parachute going back down again. It went down two or three miles away from the launch site.
DeVorkin: Yes, I can just barely see it. And now they are hauling the truck back up.
Newkirk: But the launches at that time were rather crude as well, as you can see.
DeVorkin: It is just a large truck.
Newkirk: It was just a large truck with this elevator on the back end, so that you could lift the gondola up to the point where it wouldnít be dragged on the ground, because you have gondolas of all sorts of different lengths to launch.
Now there is a last sequence of it. I think that this one is the one that contains the best footage. Thatís Jack Eddy on the right and me in the middle. There is the balloon. And see, the guy didnít realize whatís going on until he hears all this yelling and shouting.
DeVorkin: Was anybody hurt?
Newkirk: No, amazingly enough.
DeVorkin: So the crosswind was strong enough.
Newkirk: This was a young student who was with us, who broke into tears. See him bending over (chuckles).
DeVorkin: Who was he? What was his name?
Newkirk: His name was Jim Robb. He finally became a physician. Hereís everybody viewing the debris, and this one is a backwards print.
DeVorkin: Yes, the printís backwards. So really, the crosswind dragged the thing off, in fact. Is it pulling the truck, do you think?
Newkirk: This was a crosswind launch. It got to the point where the truck couldnít be steered. It had pulled it over on two wheels, and then the driver couldnít steer against the pressures on the tires.
Look at the expression on this guyís face. One of the (laughs) General Mills people. ďThis is how you do it, fellows!Ē That was the crew chief from General Mills. Thatís it.
DeVorkin: Okay, thatís the first one.
Newkirk: We had two other things on the gondola: we had a horizontal camera, and a down camera. These are time-lapsed cameras which some meteorological colleague wanted for photographic documentation of cloud formations as seen from very high altitudes, over relatively long periods of time. And we agreed. We said, all right, we wonít pay any attention to whether or not the things are loaded right or anything else like that. Give us just a simple switch that we can turn on, and we will mount the cameras as you indicate. Weíll turn them on when it goes up, and weíll turn off when it comes down. Well, once we saw the results from those cameras, we realized that they were a very nice documentation of the flight as well, so we incorporated the horizontal and down camera pictures into, I think, this film.
DeVorkin: What is the name of this one, then?
Newkirk: This is called ďCoronascope 1960.Ē This is the documentation of the successful flights in September and October of 1960.
Newkirk: This has titles on it, because we put this together. This is in color.
DeVorkin: I see. You started the truck going.
Newkirk: Thatís the way it should go. You release the balloon, and then drive the truck so that the balloon is right at the zenith; and when the balloon is right at the zenith, you release the gondola from the truck by cutting the cables that hold it to the truck, by explosive squibs, and off it goes. Thatís the way itís supposed to go.
DeVorkin: I see. Now, that trucker has to really move fast.
Newkirk: He has to be very skilled.
DeVorkin: Quite skilled, yes. That was someone who worked for General Mills?
Newkirk: That was somebody who worked for General Mills, and they had the balloon contract.
DeVorkin: And this?
Newkirk: Thereís ONR. Well, we added all sorts of title to this, because this was at a stage when quite a few scientific groups were becoming interested in doing balloon astronomy. Since we were one of the first, we asked the General Mills people to make scientific documentation films for us. And we would put it together in an annotated version, and we would give them a copy.
This is the way the balloon gondola oriented itself toward the sun. There were photocells here and here, which did the very coarse orientation of the entire gondola. And there was a fine guiding eye system which was on the sky photometer assembly itself.
DeVorkin: So then this is an actual test on the sun.
Newkirk: This is an actual test hanging from a tower.
DeVorkin: Marvelous. Did it work?
Newkirk: And there it is coming out and pointing itself at the sun.
Newkirk: And that is the coronagraph part, and thatís that subsidiary photometer that I talked about.
DeVorkin: The periscope.
DeVorkin: And it is the large tube?
Newkirk: No, the periscope was just a bunch of little beady eyes underneath. Itís that small tube underneath. It was that high precision photometer I mentioned.
DeVorkin: Now, this was all carried out in Minneapolis?
Newkirk: This was all carried out in Minneapolis, and then this thing on the side, again, a very crude sort of thing, was to record the altitude. We had a mechanical precision altimeter, and up on the top of this decapitating box, we had a camera that photographed the altimeter. Thereís Jack Eddy.
DeVorkin: Oh yes, there he is.
Newkirk: This is the coronagraph right here, that part and that upper one.
DeVorkin: And the lower one is the photometer.
Newkirk: The lower one is the precision photometer.
DeVorkin: Now, were you actually going through a real test here, or was this staged for the movie?
Newkirk: No, this was a real test. We just said, come out; weíre going to go through a test. We were doing the last minutes of testing the guiding and doing a checkout. We would do a very, very elaborate checkout, which would take us about three or four hours to complete, where we would start from essentially a dead instrument and go through a whole sequence of steps to get the instrument ready for flight. This was the box, that controlled all the functions and the guiding amplifiers and things like that. At this stage the guider was controlled by motors operating on gears. When we went from a minute-of-arc design to a few seconds-of-arc design, we eliminated the gears and used friction wheels. Okay, that white box is the guiding eye block pointing itself at the sun. You can see the occulting disk sticking out right on the top of that box.
DeVorkin: That little white box.
Newkirk: This was the only part that was staged. They said, get together and say youíre going to go (laugh). And this was the last launch, which was in October, 1960.
DeVorkin: What were the small weather balloons next to it?
Newkirk: Those are pilot balloons which were released just before the launch, like five seconds before, so that the truck driver can see which way the winds are blowing.
DeVorkin: It must have been quite a job.
Newkirk: As I explained, our distrust for telemetry meant that the entire system here was operated on a timer. What is being done there is just arming the timer. And so the timer is now running and it assumes that the balloon will get to altitude in a known period of time, that it will be at altitude a known duration. There is a good launch. This is a textbook launch, just right down the alley. There was an override so that if the gondola came down prior to plan, it would override the timer and close the coronagraph up back inside the gondola so it would be protected. This was only two and one-half weeks after the first successful launch.
DeVorkin: You said the first successful launch was several months after the first disaster.
Newkirk: No. The launches were the 12th of August, the 6th of September, and the 10th of October, I think. So it really was a very good initial conception and execution of the design for a system like that, where your scientific package is well protected. The gondola comes down and gets dragged around on the ground. There is nobody there to hold the parachute for you. It just comes down.
Hereís a very pretty sight. Oh, this is the down camera. This is before the gondola oriented itself. This is just the natural twisting and turning of the balloon as it goes up, and you see itís a time-lapse picture. That was Minneapolis.
DeVorkin: Oh, this is time lapse.
Newkirk: This is a time-lapse camera that was pointed straight down, looking straight down. And now pretty soon it will lock on the sun as the gondola orients itself on the sun at about 80,000 feet. But now itís just twisting around and round and round as the balloon cork- screws up through the atmosphere because you can never make them perfectly symmetric. There, itís orienting itself.
DeVorkin: Again, this is time exposure.
Newkirk: This is time exposure, time lapse from 80,000 feet.
DeVorkin: Why did they want to put the down-looking camera on the gondola?
Newkirk: To look at cloud formations. We just said, all right, weíll carry it for you. Okay, and there itís going.
DeVorkin: Oh, itís smooth. Look at that.
Newkirk: That final smoothness was after the second stage of guiding turned on, when the first stage of guiding turns on, it can only orient itself to an accuracy of about three or four degrees. And when the coronagraph comes out and is pointed at the sun, it is oriented to an accuracy of, in this case, about half a minute of arc.
DeVorkin: The camera is looking at convective clouds.
Newkirk: Convective clouds looking down. And thatís what he wanted.
DeVorkin: Oh, itís beautiful.
Newkirk: That was the chase airplane that went by, that little streak that went across like that.
DeVorkin: So you had a chase airplane on this?
Newkirk: Yes, as well as the scientific crew madly dashing across the countryside in a car.
DeVorkin: Is this the first time this kind of time-lapse down-looking photography was done?
Newkirk: I donít think so. That just looked so pretty that we thought we would incorporate it in our movie.
Newkirk: Thatís again, still from about 80,000 feet.
DeVorkin: You can see the cells of air. Itís marvelous.
Newkirk: Itís now somewhat late in the afternoon. You can see the shadows of the clouds getting further and further away from the clouds. And now the guiding began to get a little bit ratty. Oh, thatís the take-off. This is the horizontal camera.
DeVorkin: This is the side-looking camera. Is it black and white?
Newkirk: This is black and white. This is just going round and round and round, going up. But see, there you are. You went through the stratopause right there. And now itís oriented, coarse orientation.
DeVorkin: This is much more rapid than the last.
Newkirk: And thereís the fine orientation. Thereís the Mississippi River.
DeVorkin: Oh, thatís neat, just marvelous!
Newkirk: And see, youíre up above cirrus; see the cirrus going by at about 40,000 feet.
DeVorkin: Thatís beautiful. Yes, you see the lower stratus clouds.
DeVorkin: You canít see any stars on there.
Newkirk: No. The sky is still pretty bright, even so. I sort of wish this one had been in, color, too, because it would have been pretty. But he didnít want it that way.
DeVorkin: You can see the cross winds.
Newkirk: Oh, yes.
DeVorkin: Thatís fascinating. Oh, look at that.
Newkirk: Now weíre descending. Weíre going down slowly. Thereís light shining off lakes. Thatís coming down on the parachute. That was the sun. Hereís the balloon and thereís the parachute.
DeVorkin: I see.
Newkirk: See, they released it about, I guess, 10 or 12,000 feet.
DeVorkin: People already knew where it was going to land.
Newkirk: Oh yes. When it doesnít move too fast you can be right in on it.
DeVorkin: Boy, beautiful. What was that under there? Did you have another camera there?
Newkirk: Canít tell. It may be me. Nidey designed the gondola realizing that the most delicate point in the whole assembly, so far as precision equipment was concerned, was the bearing at the top; because if that became sticky, then youíd have a sticky azimuth drive. He designed it so that the battery boxes would break loose when the gondola hit the ground rather than impart all the impact of landing onto that bearing. He was such a good engineer that he thought through all these very subtle points. I think thatís the end of that one.
DeVorkin: Very good. Thatís a good film.
Newkirk: Well, you can copy these.
DeVorkin: Sure. What are the two other films? Is there one that we should also look at?
Newkirk: Well, we should probably look at both of them. This was the first flight of Coronascope II.
DeVorkin: And here are the second and third flights. Letís look at the first flight, if we could annotate that, that will be about all the time we have.
Newkirk: Okay. I do have a film of the flight of the FTVU as well.
DeVorkin: Ah, that would be very nice.
Newkirk: But itís a rather poor film. I think from this one you can get a picture more of what the coronagraph was like, because when the FTVU flew, it was so buttoned up in plastic you couldnít recognize it. It looks like a flying mummy or something like that. This is more of what really went on in that development.
DeVorkin: This film is labeled, ďCoronascope 2-A, 5 March 1964. And this is the one that Tousey remarked on in his review paper. You were flying this one just as he was writing that review paper, as I recall. The March 1964 launch was the first successful one with Dave Bohlin.
Newkirk: He was writing what review paper?
DeVorkin: That paper that you had pointed out in which he indicated that he had added his own retouched image.
Newkirk: No, that was not a review but a presentation at the Liege Symposium in the summer of 1964; so it was obviously after this.
DeVorkin: Yes. Okay, after this. But it wasnít in time for theta gamma?
Newkirk: It probably was, yes. But we presented the results of this flight at that symposium.
DeVorkin: Okay, and thatís the picture weíll see now.
Newkirk: Yes. By this time we had become more artistic about our movie making. This is the flight which resulted in the first observations of the outer and intermediate corona outside of eclipse.
DeVorkin: You say these are the first observations? This preceded Touseyís work, also?
Newkirk: Well, Tousey proceeded with his one that had to be retouched to show the corona.
DeVorkin: I see.
Newkirk: (laughs) That was the bone of contention.
DeVorkin: I see. Does that remain a bone of contention now?
Newkirk: Well, who cares now. He doesnít care now. I donít care now (laughs).
DeVorkin: But at the time.
Newkirk: At the time, yes, the fact that he claimed priority with a retouched photograph rather hurt some of our feelings. Itís just not cricket.
DeVorkin: I see.
Newkirk: This is down in Palestine, Texas.
DeVorkin: Thatís a very different kind of structure.
Newkirk: That building was designed and built for Stratoscope 2, Schwarzschildís large 36-inch telescope.
DeVorkin: Yes. That fellowís wearing a hard hat. We had adopted hard hats by that time as a safety measure. Basically itís the same gondola with internal changes as I mentioned; we were trying to guide to a few seconds of arc. The same basic operation — it will orient itself, or itís already oriented itself in azimuth now. See, itís doing it now. We decided some publicity obviously was useful.
DeVorkin: What does that say on there?
Newkirk: HAO. The whole front side of it is painted black to avoid scattered light bouncing into the lens. And now it comes and releases itself and points out in elevation.
DeVorkin: Oh yes, a much bigger object now.
Newkirk: Yes, itís longer but did not have a tube all the way around the optical path. That was a mistake. One of the things we found out from this flight, even though we successfully observed the corona, was that scattered light from the balloon was a problem. See, thereís the three occulting disks.
Newkirk: And then the guiding system is this tube here with the guiding lens up there.
DeVorkin: The larger lower one.
DeVorkin: So the three occulting disks were the three white spots we saw a moment or two ago.
Newkirk: Yes, there you can see them there. And this is just the support boom and the guiding telescope is down the center of the support boom.
DeVorkin: Thatís exactly what we have in the center of our FTVU downstairs.
Newkirk: Yes, basically the same design. We have now gone back to the toothed wheel, because now we can make them better. The gondola has the same basic suspension system — a brake up at the top to dump angular momentum into the balloon train — but not too fast. Otherwise, youíll twist the parachute train.
DeVorkin: Are these people from HAO?
Newkirk: These are people from HAO, a great deal of attention is given here to tweaking the guiding to get accuracies of a few seconds of arc.
DeVorkin: Was this now telemetry, or still no telemetry?
Newkirk: The gondola was controlled still by the timer. Thatís Harold Glaser.
Newkirk: The gondola was controlled by the timer system. There was telemetry of engineering results down to the ground. We had telemetry of engineering results down to the ground on the first instrument as well. But we didnít have any remote control.
DeVorkin: Did either Coronascope 1 or 2 have remote control during this period?
Newkirk: No. We were not able to change the guiding in flight or do anything like that. Now this is a big balloon.
DeVorkin: Yes. Thatís a much bigger one.
Newkirk: The interesting thing about a balloon launch is how noisy it is.
DeVorkin: Thatís a completely different kind of launch.
Newkirk: Yes. Itís the same system, but the launch vehicle is entirely more sophisticated.
DeVorkin: Now, was the larger balloon designed for greater altitudes?
Newkirk: Right, yes. This went to 30 kilometers.
DeVorkin: Yes, thatís the one you wanted.
Newkirk: And this is chasing the system across the Texas countryside.
DeVorkin: Iím going to have to turn the tape over to the other side, but you donít have to stop anything.
Newkirk: One of the troubles with that design was, even though the scattered light in the instrument turned out to be according to what we had predicted, and we did see the corona, during midday when the sun is high in the sky, we found this very strange luminous image float across the field. It was caused by the fact that the lens could look up and see the bright balloon. The light scattered from the balloon into the lens and then down to the film plane. Thatís when we realized that we had to control the entire optical path. This is just a drawing, not the real photo, but I think there is a picture later.
DeVorkin: You gave us that picture.
Newkirk: Right, thatís not a drawing.
DeVorkin: Those are the pictures. Why did you have the drawing made?
Newkirk: Just to identify the features. This is early in the morning and late in the afternoon. You can see the corona has rotated from a little arrow of coronal streamers pointing up to a little arrow pointing off to the side. The film we just saw was made for the Liege Symposium, because we knew that there were going to be people there who were interested in the problems of doing astronomy from balloons.
DeVorkin: Yes. Iím curious, you said you went back to the toothed wheel, though.
Newkirk: We have one on a coronagraph which has not flown yet — the coronagraph designed for the Solar Polar Mission.
DeVorkin: So that wasnít done then for any of the ATM era?
Newkirk: No. That was all the triple occulter.
DeVorkin: Why is the toothed wheel now considered to be superior?
Newkirk: It has one advantage which we always realized. It doesnít have to be so precisely aligned. You have to have the three occulting disks very precisely aligned. Otherwise, you lose that very effective occulting.
DeVorkin: Is that Touseyís original argument?
Newkirk: One of us thought of one thing and the other thought of the other thing. Each was out to prove that his was better (laugh). But their successful OSO coronagraph was a triple occulting disk coronagraph.
DeVorkin: Was it really?
Newkirk: Yes (laughs).
DeVorkin: So you both actually saw the value of the otherís design.
Newkirk: The one which we had planned for the Solar Polar was a toothed wheel. We recognized that keeping everything precisely aligned during an interplanetary flight was going to be very difficult. By the time of its design, the techniques of photo etching had become highly perfected, and one could make a very precise occulting disk.
DeVorkin: Are we about ready to go (movie).
Newkirk: Because of the low scattered light level you are working with, just the slightest little thing out in front of the lens can almost completely destroy the value of an image. And during the ATM flight there was a little thread stuck on the occulting disk, and the astronauts went out and pulled it off.
DeVorkin: Thatís why we have an astronaut out there doing an EVA. You notice he had his tooth brush in one hand.
Newkirk: No, thatís what they did, not a tooth brush, but a little whisker brush. (Movie begins again).
These are the two subsequent flights in 1965 when we attempted to have a sequence of observations in connection with the 1965 eclipse, to have three observations of the outer corona over a period of time to study the long term evolution. You see, now the thing looks like the FTVU.
DeVorkin: Thatís right.
Newkirk: Thatís the instrument that sits out in the lobby of the NCAR Building.
DeVorkin: Yes, itís all covered.
Newkirk: Itís all in this can. The only light that gets in is through this aperture here.
DeVorkin: The large aperture is the guide?
Newkirk: No, that aperture is basically the full aperture for the field of the coronagraph.
Newkirk: But down on the bottom of that long tunnel is the objective lens for the coronagraph.
DeVorkin: Oh, thatís a nice picture, from the side.
Newkirk: And this was not the FTVU, but it is as close a copy as you could get to the FTVU. (pause). It is still the same gondola. These are the guiding eyes, right there. Those four little eyes.
DeVorkin: Four eyes in a row.
Newkirk: And thatís another eye. Itís a coarse elevation guiding eye. That little buttonlike thing over there.
DeVorkin: Okay. And thereís a close-up of it. Oh yes, I can see them now.
Newkirk: The coarse guiding eyes would bring the sun into orientation to within a few degrees, and then the fine ones would bring it in down to a few seconds of arc.
DeVorkin: Is this telemetry?
Newkirk: It may be ground test, or it may be telemetry. I think itís probably a ground test of the guiding. Again, a great deal of tinkering.
DeVorkin: Is it making some adjustments in the guiding?
Newkirk: I suppose so. I canít remember what.
DeVorkin: Who is that?
Newkirk: This is Howard Hull. Heís an electronic engineer at the High-Altitude Observatory. That was the then new, launch vehicle for Palestine. This lobster claw at the top holds onto a fixture at the top of your gondola. These hydraulic arms open up to release it once the balloon had taken on the load.
We did not, until we flew the FDVU, have any control of the coronagraph itself from the ground. For the FDVU flight, by that time, canned telemetry units with 25 functions, or something else like that, were commercially available. NCAR had several such units, so you had 25 functions at your disposal. Then we could control the gondola and the coronagraph from the ground.
Newkirk: Hereís the launch. See how that lobster claw is holding the gondola fixture up at the top. The balloon has been released. And then when it gets — ooops, we missed it. Too bad.
DeVorkin: Oh, thatís a nice profile. This is in the early morning.
DeVorkin: Is that just a different exposure?
Newkirk: There may have been some problem with not knowing the focal ratio of the telephoto lens. And hereís the recovery off in West Texas.
DeVorkin: Thatís pretty good. So again, you used the Schwarzschild frame for the FTVU, and you added these off-the-shelf command packages.
Newkirk: Yes. Thatís just putting the gondola back together again.
DeVorkin: Preparing the frame?
Newkirk: Yes. Thatís just an aluminum frame.
DeVorkin: Is this out in Palestine, Texas, or is it backwards?
Newkirk: Oh by golly, that is backwards. No, this is in Palestine. That must have been the other flight.
DeVorkin: This is the third flight, then.
Newkirk: Yes, thatís one that took a long trip across the cotton fields in West Texas for about a mile.
DeVorkin: Yes, it looks like itís really dragged. Thatís it.
DeVorkin: So, I think we had better get you on a taxi.