Oral History Transcript — Dr. Tom Van Flandern and Dr. Victor Slabinski
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Interview with Dr. Tom Van Flandern and Dr. Victor Slabinski
Tom Van Flandern and Victor Slabinski; August 3, 2005
ABSTRACT: Van Flandern and Slabinski discuss their work in astronomy, satellite tracking, and involvement in the Moonwatch project of the Smithsonian Astrophysical Observatory.
DeVorkin:We’re going to be doing a tape-recorded oral history with both of you to get not only your individual histories, but your commentary about what the experience was like to be on a team, even though you weren’t on the same team; we know that. You do know each other. You’re professional colleagues, so you know and have a shared experience that way.
Slabinski:I would just like to say that I feel that Tom Van Flandern was the one who first taught me about satellite tracking. Even though he was off at college and on a different team, I feel that he was my first teacher on this stuff, so there should be a lot of commonality here.
DeVorkin:You did know each other when you were 17 and in Cleveland. Is this correct?
Slabinski:I think I was 18 at the time.
Van Flandern:Yes. I left Cleveland when I had just turned 18.
DeVorkin:But you were both 17 when Sputnik was launched?
Van Flandern:Yes, I was.
Slabinski:I was, yes.
DeVorkin:How did you come to know each other?
Slabinski:I was very interested in this and had found out about a project called Phototrack (that’s in my written history). I had found out about Phototrack and sent for their materials, and they sent this information about how to use the Civil Air Patrol broadcasts for satellite latitude crossings and such. After learning how to use that stuff, I gave a talk to the Case Astronomical Society (a student club). I was a sophomore then at Case (Institute of Technology), so this was like late 1958, and after the talk a freshman student came up to me. He said his name was John Eaton and that I really should meet this fellow Tom Van Flandern. He is the one that got us together at some Christmas vacation or something, had me come over to Tom’s house somewhere on Cleveland’s west side. I think he was there for the first meeting.
DeVorkin:You were at Case as well?
Van Flandern:No. I was still in high school until I left Cleveland. I was at St. Ignatius high school. Then I went to Cincinnati. As a college freshman I attended Xavier University there.
DeVorkin:So by talking about Phototrack and the Civil Air Patrol, there were several options then for tracking satellites?
Slabinski:The Civil Air Patrol is merely a means of broadcasting this information, the orbit information. They were not tracking themselves. You have to keep in mind the problems then of trying to get information to people very rapidly before you have an Internet. Thinking back on times I’ve realized how much the world has changed where nowadays you just send an Internet message, an email message to everybody. Photo Track, [I have a lot of their materials], was something put on by the Society for Photographic Scientists and Injuners — was an attempt to try to get people to take photographs of satellites from geodetic markers for mapping. It was publicized in Scientific American advertisement entitled “Get thee to a marker.” During time exposure with a camera you held a paddle or something in front of the lens at time marks to get a break in the satellite trail in the picture so that you’d have a time fix. You’d have a shortwave radio receiving time signals to know when you had done this. I don't know how many scientific results they actually got. I have no idea how much data they actually acquired, but it was a one-man show by this Mr. Norton Goodwin, who was their Legal Counsel and also a very avid photographer. Besides Tom, he was one of my mentors and helped me network with people, and also from his materials I learned a lot about methods for satellite predictions, back before you actually had a computer program. We did satellite predictions graphically because you did not have access to a computer. Tom did, but that was a really grand setup there in Cincinnati. I did have access to a computer at Case; I could only generate latitude crossings. I couldn’t steal [by inserting my card deck into the computer during the two minutes when the computer was idle between paying customers. There was no operating system in those days.] enough computer time to be able to do look-angles and all that.
DeVorkin:But you both indicated that you had been able to do some orbit prediction on your own at the time, at least in the questionnaires you filled out. Did we understand that correctly?
Van Flandern:Yes. We were pretty much on our own in those early days to determine when the satellites were going to be visible. So I guess we had some rudimentary knowledge that grew and developed rapidly, as it did for everyone. As Victor says, I had access to a computer once I went to Cincinnati. In the summers I worked as a summer student at General Electric in Evendale just outside Cincinnati and learned to program there. During the day I was doing programming applications for them. In the evening I applied my limited knowledge of programming to the obvious application I had, which was predicting the satellites. I eventually developed and found a nice program to predict all the circumstances of passages of all the satellites.
DeVorkin:From those papers that we just looked at, you had predictions from the Smithsonian to know when the satellite would be coming over, right? Or did you have to do more calculations on your own? Or you were just trying to nail it down more accurately?
Van Flandern:That’s not a simple answer. In the early days there were satellites orbits in many different circumstances. Some were totally lost. Some were inaccurate. It was not unusual to have a satellite show up ten or 15 minutes late because the orbits were just not well known in the very early days. Or to come early. The drag was not well modeled or even understood initially. There were lots of circumstances. The injection orbit would often differ substantially from their intentions. Then of course you would have some special circumstances. There were cases of things that exploded after launch. The [visual] magnitudes of the satellites would vary too. When the U.S. launched its intended first satellite, Vanguard, which was a much fainter object than any of the previous ones. It was not a naked eye object at all, and it was a challenge to be able to detect it at all. So not a simple answer. Every satellite initially was a special circumstance. It was dealt with in a different way, and it took a while for the predictions to get organized and become systematic. By the time that happened, it was sort of beyond the point when they needed these screening [optical] fences that were designed to catch satellites anywhere because the orbit was unknown or uncertain. We were in a situation where the orbits were fairly well known and they just needed to be kept track of. So the goal of the program gradually evolved from one of just catching the satellites if you could to making very precise measurements of the time and position of the satellites as they made a passage over you. Often we’d measure the position as the satellite passed the meridian or its highest point, but very often it would be going into or out of the Earth’s shadow and get nowhere near the meridian [while visible], so we would predict the best place to look and then wait for it to come through the field of a telescope. The telescopes used got larger and larger toward the end. Sometimes we’re dealing with very small fields but we would still be able to tell how many seconds early or late the satellite was compared to the prediction and whether it was off in declination or right ascension.
DeVorkin:By saying the telescopes got larger and larger, I just want to make sure that means the aperture got larger. The focal length got larger?
Van Flandern:We started getting away from these small, very wide field telescopes such as that you see there and evolved toward professional astronomical telescopes with small fields at high magnification.
DeVorkin:And that was to better pinpoint positions?
Van Flandern:Yes, because the uncertainly is in the orbits became gradually less and less. So after a while you were no longer in the game of finding satellites with unknown orbits but of refining the orbits or just keeping up-to-date on the latest in atmospheric drag variations produced on those orbits. This is published by someone else, A History of the Cincinnati Astronomical Society, but a part of that history was the Moonwatch program, and here are some of the telescopes we eventually evolved into using in the program.
DeVorkin:They’re large reflectors: 8”, 10”, 12” reflectors.
Van Flandern:Exactly. This is a Unitron telescope that does what those did.
DeVorkin:Figure 18. So is this a record of your group?
Van Flandern:It’s an entire history of the Cincinnati Astronomical Society, and I’ve made a copy for you of the four pages that include the pictures that are relevant to Moon Watch, which was probably, as my colleague in Cincinnati Dennis Smith says, probably the most important thing that society ever did.
DeVorkin:But the instruments look quite sophisticated, and it was obviously a very active society.
Van Flandern:Yes, in the Moonwatch days it was very active. When we came on the scene, they were a kind of sedentary group that would have monthly meetings with a dozen to 20 attendees and maybe once or twice a year they’d have a star party. But when we came along and started using the telescopes for satellite tracking, the observatory was sometimes active every night of the week.
DeVorkin:When you say “we,” that wasn’t you, Victor, as well?
DeVorkin:So who was the “we”?
Van Flandern:Well, when I first went to Xavier in September 1958 as a freshman, I introduced myself to Al Presnel [?], who was the team leader of Moonwatch in Cincinnati at that time. I remember our meeting of introduction. He had set up his own personal telescope in his backyard with an H-alpha filter in the daytime to show me the sun in H-alpha, which was the first time I’d seen that and it was a very impressive experience.
DeVorkin:That’s quite an unusually sophisticated thing for an amateur to have.
Van Flandern:Yes it was, and he was very proud of that. Although he was the team leader of Moonwatch at the time, it was more of a kind of sideline with him, whereas I’d just come from the Cleveland group which had been much more active. So I began making regular observations of satellites and reporting them to him, and it wasn’t long before he tired of just the paperwork involved in passing the reports on, and he said, “How would you like to be team leader?” So he turned the job over to me.
DeVorkin:So you were the team leader in Cincinnati?
Van Flandern:Yes. I don’t remember how long that was after my arrival there, but it wasn’t as much as a year.
Slabinski:Yes. These Moonwatch telescopes have a 10 or 11 degree field of view. They’re especially designed for a wide field of view because you didn’t know where the satellite was going to be. They wanted to set up this optical fence from horizon to horizon with a small number of observers. Well, with a ten degree field of view you still needed like 18 observers.
DeVorkin:Was that to cover the entire meridian?
DeVorkin:So you didn’t know where it was going to show up at all?
Van Flandern:Before the orbits had been determined, in the early days they would launch something and kind of pray that it approximated the orbit they hoped for, and many times it failed badly.
DeVorkin:So no one knew in advance. I often wondered about that, because if you had any idea, how did you motivate those people who knew they were looking at a part of the sky that definitely wouldn’t have a passage? But what you’re saying is no one knew.
Van Flandern:No one knew for sure. You would know, for example, that they had just launched a satellite at Cape Canaveral, it was in those days, and that roughly 90 minutes later it would be making a passage over somewhere, but really it was quite chancy.
DeVorkin:For both of you. Was this part of the fun of it?
Van Flandern:Oh, very much so. It was so exciting to catch a satellite in those days. I remarked before we started recording that you have to kind of go back to those days. The idea that man had put something in space so captured the imagination of the public. It was almost inconceivable. It’s something no human being had ever done before. And everyone was interested in satellites, wanted to see one. And when we would catch one it was a very exciting affair. Especially since they weren’t well predicted at all, and we would just have a vague general idea when we might hope to see one, and sometimes they would show up and sometimes not. In those very early days they were all low altitude satellites, so they would spend a lot of their time over the day lite side of earth — to be seen, satellite must still be in sunlight while observer is in darkness — or in the Earth’s shadow, and there was just a short time when they were visible, so we didn’t know initially how to tell whether a satellite was passing over us but was invisible because it was in the Earth’s shadow. It took a while to evolve that degree of sophistication into the predictions to tell when it was actually going to be in twilight reflecting sunlight but visible.
DeVorkin:Did you have the same sort of sense of excitement, Victor?
Slabinski:Well, when I finally got to find a team to get active with, it was already past that era. I made my first observations like late 1960 or early ’61. But I can comment on that. For instance, when these first satellites were launched, if they were visible from your particular city, your daily newspaper might have something on the front page, a small box saying that you could go out at this time and see the satellite and where to look, and that’s how I first saw a satellite. It was the Sputnik III carrier rocket. The 1958 Delta 2, I guess. So this was just based on newspaper predictions.
DeVorkin:So this is well before the Civil Air Patrol kind of predictions?
Slabinski:This was before I found out about the Civil Air Patrol predictions.
DeVorkin:Sure thing. That’s accurate enough.
Slabinski:You also asked how you keep people motivated for looking at the part of the sky where the satellite was not going to come. The point was when you had everybody set up; nobody knew where it was going to come, so everybody was motivated. When finally, and this would be more than a couple of weeks perhaps, when the orbit was well-known, then you dispensed with getting the whole group out. I think you can get that feel in reading through the material I sent from National Capital Astronomers, because that astronomy club’s monthly newsletter included a section about the observing they had done. You could see when Sputnik I was first launched, they were all out there at that first night or that first morning because maybe they might see it. No one knew for sure, but they were going to be up there, set up. Then after a month or two, two observers go out to track the satellite because that’s all you needed to be able to pin it down. You knew the orbit well enough. Late Note: Another time when you might want an optical fence was when one of those first satellite orbits decoyed so low that the object started to bun up like a meteor. The orbit altitude would be decreasing rapidly, so telescope pointing predictions would not be accurate. But only a few teams were in a location that could observe those last few orbits for any given satellite.
DeVorkin:So that fits your recollections, Tom?
Van Flandern:Yes. Do you remember what year Injun was? The one that exploded, the first one?
Slabinski:That’s in the stuff here. I think that was 1960.
Van Flandern:I was thinking ’61. It was 1961.
DeVorkin:The Injuns were in that period. That’s the Juno [launch rocket].
Slabinski:The thing is you could go through the Moonwatch newsletters and there’s Art Leonard from Sacramento’s reports. You were also asking about doing predictions. The materials I was showing you, like those latitude crossing sheets or what the Civil Air Patrol would tell you, what they would give you information that gave the position of the satellite over the Earth’s surface. This would not tell you where to look for the satellite in terms of azimuth and elevation, direction and how high up in the sky to look for it — you had to work that out for yourself.
DeVorkin:Each station had to work that out?
DeVorkin:Okay, that’s interesting to know. So every one of them had to take an active role in planning an observing session?
Van Flandern:That’s right.
Slabinski:In the National Capital Astronomer newsletters there they make reference to Leith Holloway, who was producing the predictions for them. I presume he was doing the work [keep] with plotting grids. Probably working with plotting grids, and if you want we’ll give you a demonstration later on how these plotting grids work. I’ve contacted him for the study, and his response was, “Why are they contacting me now?” and, “Everybody’s died off. Why didn’t they start this earlier?” I said, “Forget it. They want to talk to you now,” but I don’t think he ever sent in anything. [Laughter] Most people I’ve contacted said that they had sent in or contacted you all. As Tom said, these were low altitude satellites, and atmospheric drag was very important. What atmospheric drag does is it makes uncertain where the satellite is along its orbit. If you computed the position of the satellite with various amount of drag, you’d still have pretty much the same orbit, but where it’d be along the orbit would differ and the rotation of the Earth under the orbit would change the satellite’s track across the sky. So you had to set up, (even back in the mid ‘60s it was a case of I’m going to be out here 15 minutes before its scheduled), 15 or 10 minutes early so I can start watching for whatever atmospheric drag’s done to it to change the position along the orbit, I’m going to catch it. I had a kitchen timer there set to let me know when it was past the time, so I wasn’t sitting there forever if it didn’t show up or was too faint to see.
DeVorkin:Did you appreciate at the time the importance of this atmospheric drag phenomenon? Did you see this as an annoyance that somehow made it more difficult to observe, or was it actually a phenomenon that you were using the satellite as a probe to study? Back then, did you fully appreciate how the satellite acted as a probe?
Van Flandern:I’d say we were pretty much in the observational end of it. We were following the developments as the satellites determined the atmospheric density, variations of it with solar cycle or with altitude to determine the oblateness of the Earth and the precession of the orbits. All of these things were unknown with enough precision for satellite tracking initially, and then the knowledge became more and more exact. We appreciated the improvements as they came along, but in those early days we weren’t directly involved.
DeVorkin:I was just wondering if that was part of the motivation for you.
Van Flandern:Seeing that the good science was coming out of it, very much so.
DeVorkin:Did you include this kind of information as good science? What did good science mean to you at the time?
Van Flandern:Prior to satellite tracking, I cut my teeth in astronomy on learning how to predict things. So my first effort and first success was in predicting an occultation of a star by the moon. Then later on I learned how to do those predictions myself and then how to do eclipses, and then I learned how to do comet orbits. So I was very much into the celestial mechanics part of it. This is while I was still in high school. I remember visiting an astronomer at the Baldwin-Wallace Observatory one time and saying, “These strange formulas here, what does sin and cos [mispronouncing sine and cosine] mean?” It was well before I’d had the necessary math to do this. But I learned that math because I wanted to know how to do these things. Before satellite tracking I had learned how to compute orbits of comets or anything in the solar system from three observations. So when I got into satellite tracking, it was the prediction part that kind of fascinated the theoretician in me. I always strove to be able to get our predictions better and better for all of the satellites.
DeVorkin:Let me turn the tape over. So you were attracted to predictions, orbital mechanics basically, well before Sputnik?
DeVorkin:Can I ask what attracted you? Can you pinpoint something in your life that got you interested in such a thing?
Van Flandern:Well, I can only tell you that my earliest childhood memories are of a fascination with the sky. I remember as a very young child looking up and seeing the moon and noticing how it followed the car as we drove along [chuckles] and that sort of thing. Later on my interest was encouraged because someone knew of the existence of Sky & Telescope magazine and got me a subscription, and that allowed me to learn more about the sky and the planets and develop a fascination. I should say before that I had gone to the library and one of my first books was The Stars by H.A. Rey, which is a great way to learn constellations. One of my earliest battles with my mother — my father was long gone when I was age five, so my mother raised myself, me brother, and sister — one of my earliest conflicts was I had learned all of the constellations visible in the summer evening sky, and there were all these other neat constellations only visible in the morning sky and I wanted to get up at 4:00 in the morning and go out and observe the stars! This was not something she was eagerly accepting.
DeVorkin:She didn’t tell you just to wait a few months? [Laughter]
Van Flandern:She of course didn’t even know that was an option. I was too anxious to learn.
DeVorkin:But how did that translate to actually prediction, before you knew what sines and cosines were and things like that?
Van Flandern:Well, eventually it led to my getting a summer job in grade school to earn enough money to pay for half of a telescope that I’d seen advertised in Sky & Telescope. An actual astronomical instrument, a 4” reflector.
DeVorkin:Was that a Dynascope?
Van Flandern:A Dynascope. Yep, it was.
Van Flandern:That’s about right, yes. So I earned half the money for that and a friend of my mother’s paid the other half. As soon as I had gone through the Messier Catalogue and learned all my planets and so on, I got interested in phenomena. As I said, the very first thing I ever tried to predict was an occultation. Things developed from there. So I was motivated because of that interest in order to further it to learn the math long before I was being taught it in school.
DeVorkin:Well, that’s fascinating. Let’s move back then to Moonwatch for the both of you. Now, you were not in a team, Victor; but you were, Tom. Let’s say if I could set up a scenario for an evening’s observing, and nobody knows who’s going to get the bird, so to speak, or see the satellite. Were there preferable places to sit under the mask? Did some people push for the Equator, or it really made no difference? Were there some parts of the line that were preferable to others? Anything like a pecking order?
Van Flandern:No, we didn’t really have that many opportunities when we had a full group of people out there with a complete unknown. There were only a few occasions early on where we had total unknowns. You may or may not remember that when the US first launched Vanguard that the satellite was up there and it was broadcasting, so we could keep track of that, but the rockets that launched it were completely lost. It later turned out that they had residual solid propellant that kept chuffing after ejection of the satellite and they went into higher orbits, but nobody knew that early on. Part of the purpose of the fence was to search for unknowns like that, but that need passed fairly quickly. I think the last time we used it meaningfully was in 1961 when this Injun satellite blew up — Launch vehicles exploded after releasing its satellite — satellite did not explode! It was right after launch. It was one of those cases where there was a launch and we were looking 90 minutes later for the completion of the first orbit to verify that it had succeeded in getting into orbit, which was unknown until somebody acquired it and reported to SAO that yes, this thing was up there.
DeVorkin:Were you ever the lucky one to see the satellite when you were dealing with an unknown in a large group?
Van Flandern:Yes. Well, the Injun experience I was about to relate, we had a number of observers out there and we all got lucky that night.
DeVorkin:Really? How? It was everywhere?
Van Flandern:As things unfolded, more or less yes. We were set up. We had a grid across the sky trying to find the satellite just to verify that it had reached orbit, and we knew what we were looking for, I think it was two satellites and a rocket casing. There were three objects. So we picked up an object early on. We didn’t know which one it was, but we caught it in one of the telescopes. Ah, very exciting. It did make orbit. Got that, timed it. Moments later another object came through. Wow, okay. We got that one too. Another object. Then a pair of objects. Then three more!
DeVorkin:And at different altitudes?
Van Flandern:Well, yes, they were gradually changing their altitudes with the time. I don’t remember how many we got that first night. More than a dozen. We went up and sent a telegram off to SAO. They called back immediately wanting more details. It developed, of course, that the rocket had exploded in orbit and that there were hundreds of fragments. But the excitement that ran through our group that night when we found so many objects, all unknowns and unexpected, was just amazing. We had a few really exciting nights like that. That was probably the number one.
DeVorkin:That’s amazing. What about the social aspect of doing this? Again, you didn’t get into a team, or you had one other team member.
Slabinski:I was working solo.
DeVorkin:You were working solo. You did work in a team. Was there any esprit, a sense of identity with this kind of work?
Van Flandern:Well, I’d say yes, there was. Five years after I first came to Cincinnati, a lot of the team members wound up as groomsmen in my wedding. Yes, we shared a lot of experiences. They were young, middle-aged, and old. I had one colleague that was two years younger than me, Dennis Smith, who eventually took over as team leader when I left Cincinnati to go onto graduate school. He was my number two man, and he was almost always there at the site when I was, or he was the one I could rely on the most. For the others it was sort of a case of diminishing returns. When it was early and exciting, a lot of people showed up. As it became more and more routine, fewer and fewer people showed up. Often it was down to just me or just me and Dennis.
DeVorkin:But then you didn’t need too many people when the orbits got better known.
Van Flandern:That’s true, that’s true. But as I said, there were still many unknowns in those days. Once we developed the capability to predict things, we were pretty much set for doing interesting kinds of things on our own as observers. One night with one of the Russian spacecraft, which had an orbit inclination of about 60 some degrees, we were in Cincinnati which was just below 40 degrees. I noticed that obviously we could see it on the passes where it was passing nearly overhead or high in the sky from Cincinnati. But theoretically, we could see that just above the horizon because it was a high enough altitude even when it was passing up at 65 degrees and nowhere near Cincinnati. So we set up one night and caught the first pass not long after sunset, and then tracked it again 90 some odd minutes later when it came around again; I don’t remember the orbital period. We caught it on the midnight pass when it was up near the highest latitude of the orbit and then each pass the rest of the night as it came down again toward our latitude in the morning hours. So I think we had seven consecutive passes, which I’m sure was a record at the time.
DeVorkin:Were these records important things to obtain? Was this sort of a “try to get the most observations in a night”?
Van Flandern:At that time we weren’t doing it to break a record; we were doing it to see if we could do it. Because the midnight pass was very low altitude just above the horizon, and we had to have very accurate predictions where to look. It was very faint. Much too faint to see by eye. We had to point the telescope. It was kind of exciting to see that “hey, we could catch even that one”, and to catch it every pass all through the night was kind of a cool achievement. In a way it was just kind of something to keep the excitement there for ourselves. We were reporting all of the observations to SAO, but there was very little in the way of feedback from them. So it was kind of to keep doing new things for ourselves. There was one month when we made something like 400 observations of a variety of satellites and set the record for the number of successful satellite passes timed in one month.
Slabinski:I should say that the Smithsonian used to put out a bulletin, and there was a table in there listing the satellites and how many observations for each satellite from each station, from each observing team. So you could look in there and see what you did. Myself, I was looking, and oh there were at six from Cleveland — okay, we’re finally in there! But there are these other places, where there are 100 or more. At least Cleveland showed up on the radar screen.
DeVorkin:So would you say the Smithsonian played a role in keeping your interest up by doing that? Was that important enough? Did you say the Smithsonian is a major player here that helped validate what you were doing?
Van Flandern:Yes, the first place that I ever heard of Moonwatch was in Sky & Telescope magazine where there was an article about the Smithsonian’s plans to set up this Moonwatch network. They had contact persons for each state, and for Ohio it was Stedman Thompson. So I wrote off a letter to him from Cleveland and said, “I’m interested. Tell me what to do.” He sent information. That’s how we got initially set up. And then of course we were always reporting observations to the Smithsonian, and there would be this monthly report back for all the teams.
DeVorkin:But you mentioned that you weren’t getting too much reaction from the Smithsonian.
Van Flandern:Not to the routine observations. Of course they did call back directly the night we found that one satellite had exploded. I think we talked to them directly again the night that the rocket casing over Cape Canaveral exploded. We were trying to see an actual launch from Cape Canaveral because we figured that they would clear our horizon in Cincinnati at low altitude again in the southeast. So we had a telescope on it, and there was a bright flash suddenly. I said, “That wasn’t supposed to happen.” So we reported the observation, and we got a call back on that one too, because the rocket had exploded on its way up into orbit. It never made it. They actually sent a representative down one time. I think it was around the time we set up a conference of teams in the area. The reason we did that was because we had acquired the ability (to predict them), thanks to computer time granted by General Electric. One of the people who worked there knew of my activity with satellites and knew that I had programmed how to predict them, and I was allowed to run my program on their computer, which was otherwise very expensive. He then went to his boss and got a formal grant to allow me to run these predictions officially as an approved project, even though it didn’t have a General Electric purpose. They had something like a pro bono program. We had these excellent predictions, which gave us the great capability to track many, many satellites and realized there were teams all around us that could benefit from this, but we didn’t have the computer time to run predictions for them. So I devised a program that would allow any of the other stations nearby to take our predictions, which I would then run on four ply paper and distribute copies of to the teams that wanted them. They could take our predictions and do a lookup and apply a correction and find out where the satellite was going to be for them when we were observing it in Cincinnati. I remember that someone from Florida had come up for that meeting, and they took away the tables and wrote back and said, “Wait a minute. All the satellites are low in the northwest. Why is that?” I said, “Because they’re made for the optimum position from Cincinnati. Sorry about that.”
DeVorkin:You could only get so far.
Van Flandern:That’s right.
Slabinski:About the question about the SAO feedback or how did it feel. Remember, SAO was going to make use of this data, so you weren’t just observing, but you were observing and someone was going to make use of this data. I could go out and look at lots of satellites now, but I don’t have the motivation because no one is going to make use of my observations: I might do it for fun, but no one is going to take my stuff and reduce it and get some kind of science out of it. Late Note: Desmond King — He kept collecting visual observations for certain earth — rotation resonant orbits for many year From his out volunteer network for earth — gravity longitude depend studies — see papers in Planetary and Space Science?
DeVorkin:If the Smithsonian hadn’t set up this system, and I know this is a hypothetical, would you have done anything like what you did in terms of your predicting and the observing and that sort of thing?
Van Flandern:It would be difficult to see how future would have gone.
DeVorkin:Oh yes, it’s purely hypothetical. But you pretty much answered that you wouldn’t have done it, Victor.
Van Flandern:Yes, the fact that this data was needed and that we were doing a great service to science was an important motivator for all of us. It wasn’t just the excitement of doing it, but the fact that it was needed.
Slabinski:First the question about SAO feedback is you do get the feedback about your observations. For instance, I got some training with the Cleveland team one time. We observed some routine satellite and John Eaton sent a telegram to the Smithsonian with this routine observation. He got feedback about, “There’s no need to —” [chuckles]. Because if the orbit was well known and the satellite was not “lost” air mail reporting was timely enough. Orbits were not processed in real time.” the Smithsonian paid for the collect telegram. The team didn’t pay for the telegram. “There’s no need to send us a telegram. You could have just airmailed your predictions.” So, yes, there was feedback from the Smithsonian on that. [Laughter]
DeVorkin:Do you know who, by any chance? Do you know who sent that back?
Slabinski:No, I don’t. What was the question? Would we have done it if someone wasn’t collecting it? A friend of mine, Walter Nissen in Cleveland, though he was not a member of the team, but through the Internet he’s part of an informal group of amateur astronomers who go out and look at satellites and do things like measure the flash period, the rotation period of satellites. Then if you’ve got a rocket and because it’s tumbling, you’ll get a flash of the sunlight when it’s axis is perpendicular to the sun-satellite-observer plane. A lot of them keep collecting this data, and it’s more for their own fun. But there’s a small group that goes and looks at secret Air Force satellites. They’re from Canada I understand. The Lacrosse satellites, and they figure out from the launch times and know something about the Lacrosse orbits where to go look for it. Now these are huge satellites so that you can’t really keep these things hidden. They become second magnitude objects on an overhead pass. So they go and collect these observations and put out orbital elements on them, much to the chagrin of the Air Force.
DeVorkin:This is a Canadian group?
Slabinski:The Canadian group of amateurs. I think Americans shy away from this because you might get into security issues that you’re reporting this. However, they’ve curtailed their activities recently because they’re afraid that by making this information available that terrorist groups might now know when to hide their activities because they’d know when the spy satellites are coming over. This sort of thing.
DeVorkin:Oh, these are that kind of spy satellites.
Slabinski:Yes, they’re that type of satellites. I can say one time I called up Walter when I was teaching a course, I said, “I want my students to predict a passage of a bright satellite over the Washington area. They’re writing a computer code to do this. I said, “Send me some orbital elements.” So he sent me orbital elements on the MIR Space Station and on a Lacrosse satellite. And I distributed these elements to my students, the handout for that class at the beginning of the class. And I had an Air Force officer in the class, and he’s looking over this and he sees Lacrosse and he says, “Where did you get these elements?” and then he wouldn’t say anything more about it. So I’m just saying there are people because they feel they can put out elements, information on a satellite that nobody else is going to make public, they have a motivation for doing it.
DeVorkin:So you’re saying you can’t predict or say what motivation might have led you to do this without Smithsonian at the time, but that it is possible that you or groups that you were in or others like you would have found a reason that justified the effort?
Van Flandern:If the Smithsonian hadn’t had the foresight to organize Moonwatch, someone probably would have done it later because there was a real need in the early days. So it was good that the Smithsonian was there and had the foresight.
DeVorkin:I take then there’s no question in your mind that you guys did fulfill a need? That you provided preliminary orbital information or data that could be used for orbital information that was good enough to predict passages for photographic tracking systems and that sort of thing? Is that a fair statement?
DeVorkin:Did you ever follow that sort of issue up? Had there ever been a question in anyone’s mind while you were doing Moonwatch whether this was valuable or not? Did you ever have a discussion with colleagues or with other students who might say to you, “Come on, why don’t you go to the movies? What are you going out doing this for?”
Van Flandern:No, I didn’t. I hung out with people who were more interested in science things than in movies, anyway. I guess I kind of learned at an early age to be not very motivated by peer pressure. One day in high school, one of the teachers was kind of disgusted with all of the harassing that was going on by high school kids, picking on certain students. I tended to stick to myself and had my own circle of friends, so I didn’t pay much attention to it. But when he made this remark I could think of two or three people in the classroom that he must be talking about, but he used me as an example.
DeVorkin:As somebody who was picked on?
Van Flandern:Yes, and he used the word “eccentric” [chuckles]. I didn’t see myself that way, but it kind of reinforced my view that I needed to keep my distance from the regulars, because there was a tendency to treat kids badly that were different.
Slabinski:The comment about keeping track, there really was no other way of keeping track of these satellites up until the time the Navy put this radar fence across the Southern United States to be able to catch every object that would cross the United States. This came in I guess somewhere around like the late ‘60s.
Slabinski:I don't know the exact date. Again, I wasn’t always necessarily current with everything. My experience was then in 1970 I went to work for Comsat, and occasionally I’d be involved in launches of communications satellites, and sometimes we would have a launch failure where a satellite would be left in low-Earth orbit. Within a couple of hours we would find out about a new object that was in low-Earth orbit that was presumed to be our satellite. By working with people at MIT’s Lincoln Lab who were kind of the go-betweens between NORAD and civilian agents and civilian groups, we would get orbital elements on these objects and then we would go after them with our tracking stations. Because we had radio tracking systems with narrow-beam antennas, we would generate predictions and go looking for these objects and generally find our satellite left stranded in low-altitude orbit.
DeVorkin:Where were you when you were doing this?
Slabinski:Comsat here at L’Enfant Plaza and then later INTELSAT. I’m just saying that when that radar fence came in, which was then all weather and it would pick things up and a number of objects, we put the call in: “We’ve got no contact from our satellite. It should have been in the transfer orbit going out toward geostationary altitude, and none of our stations have picked it up.” The radar people go, “Well, we’ve got three objects.” And it’d be the right inclination, right orbit plane expected from the launch. This is just background of when the need for Moonwatch started going away. The other thing is this Norton Goodwin fellow I mentioned with the volunteer satellite tracking program. He tried to encourage people to make observations of high-altitude satellites and generate their own orbits. There was one person who did that. It was Wilcox P. Overbeck who wrote pamphlets on how you could do this. This Mr. Overbeck generated his own satellite orbits from his own observations using a desk calculator. If you want to look at the stuff I brought, on the postcard predictions they’d include the orbital elements that Mr. Overbeck had derived, and maybe there are a couple other people that did a few satellites, but I don't think it much caught on. So this is just kind of background on how motivated people would be if there hadn’t been the Smithsonian, someone making use of the data. But the premise was well, people are not going to make use of just random observations, but if you derived orbits from your observations, then they might make use of your data because you handed them the orbit.
DeVorkin:You sound skeptical about that.
Slabinski:I’m skeptical of it. I got very discouraged because I lived in the city Cleveland where you never could be sure that if you spent an hour generating a prediction in the afternoon when it was bright and sunny whether it wouldn’t cloud up that evening, and the idea of getting observations over three or four days consecutively, having that kind of run of good weather in Cleveland, was just not heard of.
DeVorkin:Is Cleveland worse than Cincinnati?
Van Flandern:Oh, much so. The storms off Lake Erie. Two nights stand out in my memory in that connection. One night we were very anxious to get a particular nice, bright satellite which was going to come right overhead for us, so we aimed out on the horizon over the lake to pick it up quite early. Less than ten minutes before the satellite should have appeared there, this cloudbank appeared on the horizon — the sky was perfectly clear overhead, then that cloudbank appeared. It started moving in and moving in. We kept expecting the satellite to clear at any moment, but it didn’t clear the cloudbank until it was up about altitude 60 degrees. We finally saw the satellite, and within five minutes it was a deluge, high winds and heavy rains. So it just barely out-raced the clouds. Another night where there was a weather incident that sticks in my mind (both of these were in Cleveland), we went out for an early morning passage, and our observing station was on the lakefront. It was in a park. Ordinarily that park was closed at night, but we had special permission to be there. We had an observing area where we had to go between two fenced off areas that were tennis courts or something else and then out onto an area that faced the lake. So we pulled into the parking lot, and although the sky was clear that night, there were very high winds off the lake, very high; it was screeching. We got out of the car and you could barely stand in the wind. And we couldn’t hear anything. Shouting to one another when we could hardly hear each other talk. So we grabbed our equipment and made our way between the two fences down to the lakefront. My colleague lets out a screech and I said, “What? What?” He says, “I just stepped on a rat.” They couldn’t hear us coming so they hadn’t scattered! [Laughter] It was completely dark too, of course. So they had neither visual nor audio cues.
DeVorkin:Were there ever any safety considerations for either of you? Did your parents ever worry about you running around at night like this?
Van Flandern:In those days it was a lot safer than it is these days.
Slabinski:I observed from my backyard. There was a question about predictions and the uncertainties from atmospheric drag and things, and that we had to do our own updates. But the update process could be fairly crude. For instance, if a satellite hadn’t been observed for a while and you went out and looked for it and found that it came ten minutes early, well, this told you when you went for the next day’s pass to expect it approximately ten minutes early. So you were updating your predictions just by looking when you saw it on a pass at a particular part of the sky versus when the prediction sheet said it should have gone. Okay, you already know to look ten minutes early. Now you may find it 11 minutes early or something like that, but still you’re in the ballpark. I don't think I ever got a run, but you know just in my mind say well, it was ten minutes and then 11 minutes. I know I’d try 12 minutes the following night. You didn’t have to be necessarily too mathematically sophisticated to do some of this.
DeVorkin:The atmospheric drag could be variable depending upon where you’re catching it in the orbit, right, and that would change?
Slabinski:No, atmospheric drag effects tend to be cumulative. What it does is it changes the period, shortens the period so the satellite starts pulling ahead of its position. If atmospheric drag suddenly got say 50% greater, well, that means the satellite would start pulling ahead of its orbit more and more. It’s sort of if it gets greater it’s going to pull the satellite ahead in its orbit, so you’d know just to keep looking ahead.
Van Flandern:Yes, I confirm that. We didn’t do orbit determination with our observations, but it was a natural thing to do when you’d see that a satellite was running ahead of or behind schedule to just change that one parameter, the drag term, the t2 term in the expression for the satellite longitude, and adjust it so that the predictions were then on time and then continue the future predictions on the basis of that correction. That would then be very good for a few more days, a week, whatever, until the cumulative effects of the changes in atmospheric drag would take it off schedule again. So we could do better that way than the approximately weekly or so updates to the predictions they sent.
Slabinski:There was a second order thing you could do. If you imagine the orbit as a wire out in space and the Earth is rotating underneath that if the satellite is coming late, because of the rotation of the Earth, you’re going to have to look at a different altitude. So some people would work it out: I should be looking at a certain altitude and change my altitude at half a degree per minute (I don’t have an exact rate). In some cases where I suspect it might be early I would look a little to one side of the predicted orbit, and then as I got close to the time and my kitchen timer went off I’d move down to the orbit, just to try to bracket the part of the sky you should be looking at. You had an earlier question: were we motivated about the science that’s coming out? Although I was not on a team at the time, Sky & Telescope had this “observing the satellites column” where they would have columns about what was happening with the satellites. I can remember one of the early ones. It was one of these carrier rockets was coming down, and they showed a graph that seemed the amount of drag was going up and down. Jacchia is the name that sticks in my mind. He was the one that was analyzing all of this stuff at SAO. He’s deriving all of this, and I presume it was from Moonwatch and probably the BakerNunn stuff. First of all they said, “This is probably because it’s a rocket and it’s presenting a tumbling cross-sectional area to the atmosphere it’s moving in. First of all, it’s moving like this, but then as the atmosphere has gotten denser, it kind of went like this nose first because of its tail fins reacting to the atmosphere, and that’s why the drag fell down or decreased. A couple of months later someone said, “It’s going up and down with the sunspot number,” or something like that. My point is, in reading these things in Sky & Telescope, I had a feeling of what science was coming out of this. Of course I wasn’t on a team yet to apply this, but I’m just saying that information was out there in a place that an amateur would find out about.
DeVorkin:For either of you, was there any sense that you were participating in a Cold War kind of activity? That this was something that was going to help national security or beat the Russians or remain competitive with the Russians? Were the Russians a factor in your enthusiasm in any way? And were they a positive or negative factor, let’s say?
Van Flandern:That was the kind of sense of the society of the times. It was a shock when the Russians launched the first satellite before the US. Then it was another shock that when the US put one up the first effort was a failure, and then when they finally did get one up it was so tiny compared to the Russians. Then the Russians put a dog in space and they were launching these huge payloads and put a monkey —
Slabinski:The U. S. put a monkey into space.
Van Flandern:I don't remember all the sequence, but they were doing sophisticated things. So yes, there was a real sense that there was a competition and that the United States needed to catch up. In Moonwatch we just felt as though we were just contributing to the US effort. We didn’t really see any direct connection with whatever the Russians were doing.
DeVorkin:But there was a sense that you were participating in something that was of national importance?
Van Flandern:Yes, I’d say so.
DeVorkin:Were you worried about the Russians at all before this? Or even concerned or aware that the Russians existed?
Van Flandern:Yes, in the ‘50s there was the Korean War going on. I remember as a child some of the aftermath of WWII. There was a parade in Cleveland. Not exactly a parade, but a kind of affair. MacArthur was it? One of the generals had arrived back from the war and arrived at the airport and went and drove through town. Everybody was lined up on the street to see him. When the Korean War was going on, I remember asking my mother — you don’t really get a sense of it as a child, but I said, “What happens if we lose the war?” That was a big concern as a child to me. It seemed to me as though the only possible outcomes were win or lose. For the most part, it was just whatever was going on in the society, and it was a very different society than today. On the negative side, it was the middle of the McCarthy Era and it was a very paranoid society. On the positive side, it was a much more ethical society, ethics-motivated society than anything we’ve seen since. Very different.
Slabinski:My feelings were that I was concerned that we should beat the Russians, but I didn’t feel that participating in Moonwatch helped us one way or the other. I mean participating in Moonwatch was participating in science, but that was independent of who was winning the space race. That I was not helping the space race one way or the other was my feeling. I was aware of the Russians. I was worried about the Russians. I would say that I can remember I was in Catholic school, and this was the late 1940’s or around 1950 and I was in 5th or 6th grade, we had to read — I forget what kind of book it was — but it was about countries or politics or something. There was half a page devoted to how a communist party takes over a country. I’d say if we read it now we probably would not think there was anything alarmist. It’s how do you ferment unrest and capture control, whoever’s in power, and you’re concerned about that because then that meant religious persecution. I would consider that still today that was just a straightforward explanation. Even today, “If the wrong guy gets on the Supreme Court “our rights are gone.” You know, we have hysteria today.
DeVorkin:Well, then what about the IGY? Were you aware as high school students or as college students of the IGY, what the IGY was, and this launch was all a part of something much larger, a much larger scientific endeavor? Were you aware of that?
Van Flandern:Yes, emotionally, yes. Most of my science news was through Sky & Telescope magazine in those early days, but they were certainly keeping us aware of the IGY plans and that our effort fit right in with the broader plans. So a general awareness.
Slabinski:In filling out the questionnaire where I was asked when did I first get interested in space travel. I hadn’t thought about it until I did the questionnaire, but as far as people who read newspapers and just paid attention a little bit to what was going on, we were all prepared for the launch of that first satellite. It’s that when the Russians launched it was how could they beat us, but no one had to explain to us what a satellite was. I mean if you think back about it, no one had to explain it to us. People might say, “What keeps it up there? Why doesn’t it come down?” But because of science fiction movies and things, we all knew if you went up into space somehow you kept going around the Earth. I’d say this goes back to the Collier’s magazine articles. It was all laid out there. Then when it came along… The IGY, it’s in my questionnaire; I was listening to a radio program called Monitor. I forget whether it was NBC or whatever it was. As it was a Saturday afternoon, I would be doing things in my basement. I was a teenager, and I had my radio on as even teenagers have today, and listening to Monitor because they sometimes would have Bob and Ray and things like that. There was this one announcement, “Calling Buck Rodgers, the White House announced today that for the IGY the United States is going to build a rocket and launch a satellite.”
DeVorkin:And they started it with saying “Calling Buck Rodgers”?
Slabinski:That was the audio headline, “Calling Buck Rodgers”.
DeVorkin:That’s how they got your attention?
Slabinski:Now one of these days I’d like to see a Buck Rodgers movie to know what it’s all about. I’ve just seen snippets of Buck Rodgers. There was some snippet of a Buck Rodgers movie in one of your exhibits. It may not be here anymore, but back when you first opened.
DeVorkin:Oh, it’s probably still there. Tom, you were certainly self-motivated and very interested in orbits and predictions, and this fell right in perfectly for you. Did you have a prior interest as well, Victor?
Slabinski:In 1950 I was ten years old and my father took me to two science fiction movies. My father was interested in science fiction: Rocket Ship XM and Destination Moon. That kicked off an interest in science, so I went to the neighborhood library and I start reading all of the astronomy books and science fiction books, but I never connected with Sky & Telescope. That was only at the downtown library. And although my parents encouraged stuff on it, like we had the publisher Zim nature series, the golden nature guides, there’s one with stars. We had the star book and I’d try to learn the constellations, and although it talked about Sky & Telescope magazine for more information, it just never entered my mind that if I had asked my parents they would have bought this for me. Looking back now I say, well why didn’t I do it? It just never occurred to me. So I never had a telescope. I was wondering how I could get a telescope. In part as a kid I didn’t appreciate that there were stores that had things you could go and buy these things from. I did not appreciate that you could go into a hardware store and buy the exact kind of screw you want — the length, the thickness — because my father didn’t do these kind of things. A hardware store you went to buy paint and paintbrushes. There was hardware around the house and my grandfather had lots of junk hardware and things, but you went to see your grandfather and you pulled the screw out of his rusty screw collection. It wasn’t until I was like a junior in high school I discovered what hardware stores sold.
DeVorkin:So you never saw an ad for a Dynascope?
Van Flandern:I think I still have that Dynascope, by the way.
Van Flandern:I think I do.
DeVorkin:We’ll talk. We don’t have a Dynascope in the collection, and I think we should.
Slabinski:I would go for my eyeglasses because I needed eyeglasses from a young age and I’d say, “You know, I’d like to get lenses for a telescope,” but no one ever would tell me, “Well, write to Edmund Scientific.” I was not in the right circles.
DeVorkin:They advertised in Popular Science and Popular Mechanics and different things like that when they were the Edmund Salvage. So you just didn’t run across some of the stuff?
Slabinski:We were into electric trains.
DeVorkin:Yes, those were the two big competing things in my life too, electric trains and telescopes.
Slabinski:But I knew I had to study all the science and math I could get, so I got no argument from my high school when they said, “You’re taking algebra. You’re taking all these science courses.” I knew I needed that.
DeVorkin:But did you get any help from your high school, or was your high school at all a factor in your interest specifically in astronomy?
Slabinski:No, and I would say Catholic schools still are not strong on astronomy. Not in any kind of negative thing, the way you think about Creationists don’t want it. It’s just that’s not part of the basics. Basics in a sense of you learn to read, you learn your grammar, you learn phonics, you learn math, you were well grounded on that, but we don’t have money for other things. My parents, though, encouraged me to do things. I had freedom at home to do things, but I just didn’t ask the right questions.
DeVorkin:So I’m not quite clear how you got interested in astronomy and specifically the Moonwatch kind of activity. Was it through Tom and people like Tom?
Slabinski:When the Space Age started and now I was in college, there was Scientific American in the library and I started reading that more regularly. Being at an Injunering school, we had an astronomy club and we had a young radio astronomy professor there who was working with Standard Oil of Ohio [SOHIO] Research, the radio satellite tracking group out there in Warrensville Heights.
DeVorkin:You were at Case?
Slabinski:I was at Case. This young astronomy professor was the advisor to the astronomy club, and at every monthly meeting he first of all gave a five minute report about what’s happening with the satellites, what we’re learning from the satellites. I remember him saying, “Well, from atmospheric drag we found out that the atmospheric density is three times as great as what geophysicists thought before there was a satellite up there.” This kind of thing made a big impression on me about what we’re finding out from the satellites.
DeVorkin:So you were exposed immediately to that?
Slabinski:But I just didn’t have any knowledge of the team.
Van Flandern:Was his first or last name Grant?
Slabinski:Yes. Name was Gordon Grant. He committed suicide near the end of my freshman year.
DeVorkin:Let’s move to the influence that being part of Moonwatch had on your later careers, in your career choices. If you could characterize it for us.
Van Flandern:I wound up going on to get a degree in astronomy specializing in celestial mechanics. From Xavier I spent a year at Georgetown University in graduate school, and from there I went to Yale. So I actually got my degree in celestial mechanics at Yale in 1969. Obviously that Moonwatch part was a major and integral part of my training in celestial mechanics as a youth and developing interest in it, and in astronomy in general.
DeVorkin:It sounds like without Moonwatch you still would have gone into some sort of astronomy.
Van Flandern:I’m sure of that, yes. But it was a major part of my development. Certainly it helped develop and further my interest in predicting phenomenon in the sky, right down to the present day where I was way out on a limb predicting what comet Tempel I, the Deep Impact Mission would produce, and so far so good.
DeVorkin:Well, you were also involved in the Markowitz moon camera project were you not?
Van Flandern:More as a user of the data, but I wasn’t directly involved in the instrument itself.
DeVorkin:Okay, so you stayed in the mathematical computing and predictive side of things?
Van Flandern:Well, no. I kind of kept one foot in each camp, observational and theoretical, for many, many years. I was an observer of occultations and comets and so on for a long time. In later years I’ve kind of tended to land in the theoretical camp.
DeVorkin:I was wondering when you were at Xavier did you have any contact with Herget at Cincinnati?
Van Flandern:A fair amount, yes. He was not very approachable. But yes, I met him then and ran into him regularly for years after at Division of Dynamical Astronomy meetings or things like that.
DeVorkin:Did he have any influence on you in the ways that you gained computer time? Because I recall, at least from oral histories with him many years ago, that he ingratiated himself to the local commercial companies, large industries and companies and helped them with their computer systems in order to get computer time, because there was no other way. Then some of the comments you’ve had a little while ago sort of sounded like “ah”, it’s the same sort of thing of how to get access to big computers in the 1950s.
Van Flandern:It was tricky in those days, yes.
DeVorkin:Were you aware of what he was doing?
Van Flandern:No. We had no contacts that were helpful to either one of us prior to when I got my degree and knew him as a young but fellow professional. He was really never a mentor in any sense. [Hands over a copy of a booklet] This is a complete history of the Cincinnati Astronomical Society.
DeVorkin:I’m going to try to find that. I’m sure we can find a copy here.
Van Flandern:It turns out there are two organizations: the Astronomical Society and the Astronomical Association. Herget was pretty much the one in charge of the Astronomical Association, and there was a long history way before I came on the scene of animosity between the two groups. So without my knowing about it or participating in it, there was already a kind of a “we’re not going to talk to them,” attitude when I came on the scene.
DeVorkin:That’s too bad. He also had the Minor Planet Center there, so that was not a factor?
Van Flandern:No. Years later at the Naval Observatory, Ken Seidelman was a colleague of mine and then later became director of the Nautical Almanac Office. He was a student of Herget. So he was kind of more involved with learning astronomy from Paul Herget. The years I was in Cincinnati, other than visiting the observatory as a member of the public, I really never had any interaction with him.
DeVorkin:And how about your course trajectory, the influence of Moonwatch?
Slabinski:Well, as I kind of made clear in the questionnaire, my course correction was frustration in trying to find an active Moonwatch team to connect with. So I tried these other things like Phototrack, though I never actually did photography or such.
Van Flandern:Did you know Tom Petrie?
Slabinski:I met Tom Petrie, but Tom Petrie was not somebody you could talk to. He spent some time at Case back when I was a graduate student there, and I once sat down with him at lunch for instance. Most people if they have a specialty and you sit down with them at lunch and start asking about their specialty, they’re happy to talk about their specialty. Well, Tom Petrie kind of gave me the feeling of “you’re bothering me”. [Laughter]
Van Flandern:I don't know the transition from Petrie to John Eaton as far as team leader of the Cleveland team. Do you know anything about that?
Slabinski:Well, Tom Petrie left Cleveland also to go away to college. So that’s like what removed the leadership from the team. Then as far as I know, for Cleveland Moonwatch people, the only people I’ve ever met were John Eaton, you, and Tom Petrie. I doubt that I’ve ever consciously met anybody else there.
Van Flandern:These are some clippings my wife saved, newspaper stories from back then, and it shows the principals. That’s Tom Petrie. I guess that’s not in this one, but in this one I gave you copies of these before. This is Dennis Smith, who was my second in charge in Cincinnati who took over when I left.
DeVorkin:He’s on the right of figure 18. Could we have these copies?
Van Flandern:Sure. Plus a handout I have for you; there’s contact information for Dennis Smith. I happened to talk to him just last week. He called up about Deep Impact and was reminiscing about Moonwatch days, and it turns out he still has a basement full of Moonwatch artifacts. He has a history that goes on beyond when I left that area. There’s a telephone number there somewhere.
DeVorkin:That’s the one we need, yes.
Slabinski:But it was frustration trying to get connected with people. There was this professor at Case who was doing radio tracking at SOHIO Research and I talked to him and said, “Do you need someone to do computer data keypunching for you?” I offered my services. No, he didn’t need any help. John Eaton took me in to visit SOHIO Research on a Saturday and showed me their computer program for doing predictions, and I looked at the code and I said, “Oh, this is terribly inefficient.” The comment was made how long it took to produce predictions because they didn’t have a mod function so they always used repeated subtractions. He gave me a copy of the code. I wrote up and suggested improvements to their code and mailed it in to them, hoping that I may get a summer job or come and volunteer thing. Somehow the letter got delivered to the wrong person and it got delivered to the guy’s boss who looked upon it as a criticism that this guy was doing a lousy job. Again, I’m not quite sure. I never quite got the story straight, but I heard things like, “Who is this Victor Slabinski, and what is he trying to do?” So that didn’t work out.
DeVorkin:Was this FORTRAN?
Slabinski:I don't remember. I don't think it was FORTRAN.
DeVorkin:You were able to do machine code at that time?
Slabinski:That wasn’t machine code. It was in some format that I could follow and duplicate. I don't remember what it was. I had written a similar program for the Case computer.
DeVorkin:Oh, so you already had computer experience.
Slabinski:Yes, I had computer experience, and I had faced this problem of how to do a mod function under the Bell interpretive system. I finally discovered if I added 108 to the number I could round off all the decimal places. So I’d add 108 or something like 108 to the number that I wanted to get the decimal part of, and then subtracted 108, gave me the integer part and I could subtract it from the number.
DeVorkin:But you were at Case? What was your major at Case?
Slabinski:I was in physics.
DeVorkin:And you stayed in physics with the intention of doing what?
Slabinski:Well, I was in physics because in part Wernher von Braun was a physicist. He got his degrees in physics. I also found physics was coming to me more naturally than chemistry. I wanted to build rockets, so I thought chemistry would be the thing to do. I also found I did well in physics without all that much effort while chemistry, especially chemistry lab, was something I was having trouble with.
DeVorkin:But that was your motivation?
Slabinski:That I was in physics with the idea I wanted to do something in space, build rockets or something. What I discovered was that I had an affinity for doing satellite orbits calculations and this kind of stuff. Finally after I finished my four years at Case, I went to the University of Maryland for a year and while I was at College Park, Maryland. Here I took the bus downtown to visit Norton Goodwin (Phototrack) to change the address on the prediction postcards he was sending me. I decided, instead of handling this by the mail, I’d visit in person. Maybe I could get a ten-minute tour of whatever he was doing there. I came in and he was trying to work some mathematical problem and told me what he was trying to work out, so I sat down next to him and started expounding on whatever he was trying to work out there. This made a big impression on him. I was what he was looking for: someone who could do the mathematics of these projects he was trying to do. So I quickly became kind of like a consultant to him and he would write me letters and I’d give him responses back. Although he loaded me up with Phototrack material, I never actually set up a camera to do anything. Through him I made contacts with other people, which was a big help in my career. Finally I found through these postcards he was sending there was somebody called Herman Michielsen at Lockheed in Sunnyvale who was looking for people to observe Agena rockets, because he was trying to do gravity field work. At the time there was a problem. When people derived gravity fields, they didn’t appreciate you needed to use satellites with different inclinations to get a good solution. You had satellites clustered at 30 degree inclination from American launches, due east from Cape Canaveral, and then you had the 63 degree from the Russian launches. Well, then there’s the Air Force Discoverer Program, parachuting photographic film canisters to Earth. They left their agena rockets, or maybe the Agena rocket was the spacecraft probably too. Well, he was looking for people to make observations of those satellites because he wanted to study gravity field things from them. He didn’t care whether you were a member of a team or not. If you made observations, you got look angle predictions by airmail special delivery. And here finally someone wanted my observations and I could make observations. I could see satellites, so I observed for him for a number of years until his program kind of fell apart.
DeVorkin:You were a grad student by then.
Slabinski:I was a grad student.
Slabinski:No. I did spend a year at Maryland, and I don’t regret my year at Maryland, but for various reasons I went back to Case. Case was what I was looking for. Grad school there was entirely different than what the undergraduate grind had been.
DeVorkin:Did you have any courses from Shankland?
Slabinski:I knew who he was. I heard lectures by him, but I never had any courses from him. With Norton Goodwin, there was Overbeck who would say derive your own orbits, and he was going in for more and more accuracy. You know, how we could get 1/100 of a degree accuracy in all of this. I then went to the library and started learning a little bit about perturbation theory, enough to do a little analysis. I wrote to Norton Goodwin and I said, “Hey, this observational accuracy doesn’t matter. You’re neglecting short period perturbations to the orbit which are larger than the observational accuracy you’re getting.” Your accuracy is not justified.” Overbeck wrote back to me. He said, “You write to the Smithsonian and you ask for Special Reports number such and such and you read them and tell me what they mean.” As a result of that, I then pulled out Moulton. I learned perturbation theory from Moulton, Celestial Mechanics book, Forest Ray Moultron’s classic. I asked for it as a Christmas present once I started getting more understanding about these things and found it in the library and said, “People want to know what to get me for Christmas? I want Forest Ray Moulton’s An Introduction to Celestial Mechanics, 2nd revised ed. 1914 book.”
DeVorkin:I don't think too many kids ask for that.
Slabinski:Maybe I was a graduate student already. But anyway, I learned perturbation theory between that and Kozai’s 1959 A.J. classic paper. I reproduced the first half of Kozai’s paper by hand; of course, the way Kozai would have done it. I never did the second order thing.
DeVorkin:He was at SAO for a good while during this period before he went back to Japan. Did you ever want to go to SAO to work there? Either of you?
Slabinski:Again, I felt I should get a degree in physics because I wanted that kind of background. What I did not appreciate is that you actually could be hired to do all this orbit prediction type stuff. In part, because it came so naturally to me, I didn’t imagine that everybody couldn’t do it. I mean, yes, a lot of people did the predictions from the Moonwatch team. Well, I just got more into perturbation theory. I was already so entrenched in Case Grad school, I wasn’t going to up and leave a degree program where I had finished course requirements and passed the Ph.D. qualifying exam. I was in Grad school a long time. I had trouble with thesis projects that didn’t work out. When I finally got out in 1970, there had been cutbacks. I would have loved to have worked there. I remember talking to you [Van Flanderen] in ’69 at the AAS meeting in New York City, “How are things at Naval Observatory? Any possibilities?” You said, “Victor, no. We’re not sure how long our jobs are going to last.” Although I didn’t think so much about Smithsonian as about Goddard Space Flight Center, but people weren’t hiring. I wrote to Norton Goodwin and I said, “I’m looking for a job and I applied at these places.” He said, “Well, your buddy Perry Klein at Comsat says they’re looking for someone in celestial mechanics.” I thought, “They must have 100 celestial mechanics experts and they’ve worked out third order perturbation theory for the satellites. They don’t need another one, but I’m going to send them my resume because it’s only the price of a stamp. When I wind up driving a cab for a living I don’t want to look back wondering what if I had mailed something to Comsat.” I said, “Norton Goodwin’s really lost it this time suggesting Comsat.” I mailed my resume before Christmas, and shortly after Christmas I get a phone call from them. “When can you come down for an interview?” Someone said, “Well, even if you don’t want to work for them, no one’s had you in for an interview. Go for the experience.” So I went for the experience. I had read a book about the military industrial complex that had had a chapter about how evil Comsat was launching their commercial satellites with rockets developed at government expense. I went there for the interview, and “Gosh, these are just normal people” that I’d be working with. There were only ten guys in that group, and two of them are computer technicians. They got to work on all this interesting stuff. Well, okay. They asked me if I had used Kalman filters in my thesis work (it’s a mathematical thing). I swallowed hard and I just thought, “I’m the wrong person.” So I said, “No, but I could probably learn.” At that point I felt I’ve blown this interview. I should relax. Just enjoy the interview. At the end after lunch in the afternoon I said, “Well, it’d be interesting to work here.” They said, “Do you want to discuss benefits?” I said, “Well, if you make an offer, that’s the time to talk about benefits.” Why should I waste their time talking about benefits? They’re not going to hire me. But ten days later there was a letter back in Cleveland, “When can you start?” They wanted me to come to work. They were on the bottom of my list. I hadn’t gotten my resumes off to the scientific places where I felt I would want to work.
DeVorkin:Did you apply to the Smithsonian at all?
Slabinski:No. But because of a talk on my dissertation I had given at a AAS meeting, I had met someone from Langley, Frank Hohl, who said, “Have you considered doing this?” It was ionosphere interactions with satellites. I said, “Well, no. I understand NASA isn’t hiring.” He goes, “No, we’re hiring a few.” He sent me an application for a post-doc thing and I was busy filling this out and this letter came from Comsat. What do I do now? Well, take the real job offer. I was under the same boss for 25 years and did well.
Van Flandern:Victor is not only a leading authority in rotational dynamics and celestial mechanics, but also the author of one of the most useful papers of all time that was never published. Partly I think because I had asked a question. I’m not sure what motivated you, but he had developed all of these upper limits of the size of a zillion different little perturbation effects that could be important for orbital dynamics of the Earth and the Solar system. Little things, like what is the upper limit to solar radiation pressure? How big is the solar wind effect? What about electrical forces, asteroid impacts, meteors? You name it. He set a variety of limits on these things.
DeVorkin:Assigning limits based upon present knowledge of orbits or what?
Slabinski:Knowledge of geophysics. It was basically Tom who started me on this. It was something that was near and dear to my heart [non-gravitational perturbing forces]. That’s one reason I jumped on it.
DeVorkin:So the largest solar flare you can imagine, what would that do to the Earth’s atmosphere, and how would that perturb the Earth?
Slabinski:His question was how would it perturb the orbits of the moon and planets.
DeVorkin:Oh, the moon and planets. Not a satellite or something?
Slabinski:Not a satellite, no. The satellite part was my Ph.D. dissertation. The ECHO satellites.
DeVorkin:So you were at Case with a Ph.D. in orbit theory?
Slabinski:I worked on atomic spectroscopy for five and a half years in a laboratory working on these experimental atomic physics projects that never yielded any results. After the second project failed, I changed thesis advisors. I told the department that I wanted to do something different, and I proposed a project I wanted to work on. It was an ECHO-satellite interaction with the ionosphere. People had predicted something called Alfven wave drag. There were big names on it: Sydney Drell, Henry Foley at Columbia, and Mark Ruderman who went on to grow whiskers on neutron stars or something like that. It was to work up observational evidence. I was already into orbit perturbation theory. The department head said, “Well, if you can find yourself a thesis advisor, but how are you going to support yourself?” I said, “Well, I know that the department is paying me: 100% of my assistantship for my teaching. I can stay teaching.” Well, it turns out they really liked having me teach Junior year Physics Lab. So I got myself an advisor in the astronomy department thanks to an intervention of Dr. Sidney McCuskey.
DeVorkin:McCuskey. Who was your advisor though?
Slabinski:Dr. Joseph Dolan. He’s at Goddard now. He didn’t get tenured because when he came up for tenure, University was not giving tenure to anybody anymore. This was the result of financial difficulties at universities then. But anyway, there was a lot of contact through Norton Goodwin. I got this job in the communications industry at Comsat but still kept my scientific interests like writing the unpublished paper we talked about.
Van Flandern:We had one woman member of our Moonwatch team in Cincinnati. I can’t remember her last name; Mary something. Dennis Smith would know it for sure. By and large in those days the male/female ratio in science was just out of sight.
DeVorkin:So it would be considered almost unusual to see a woman there?
Van Flandern:Yes, in those days it was.
DeVorkin:You don’t remember who she was or anything?
Slabinski:I can’t remember ever meeting any female satellite tracker or any correspondence with anybody like that. Well, this report has a woman author.
Van Flandern:I can’t remember her name at all, but somebody from the Milwaukee Moonwatch team came down to visit me.
Slabinski:She was head of the team, I thought.
Van Flandern:I think so, and that was a woman. She came to visit me one time in Cincinnati. She was interested in what we were doing there that was getting our observation totals up so high. I cannot remember her name. It may be Margaret.
DeVorkin:Did you know of or pay any attention or keep any track of the regional meetings of Moonwatch or the national stuff? There was a woman; Grace Schultz Spitz who was something like the executive secretary was very much involved. She later was the wife of Armand Spitz. Did you read any of the stuff they did or they organized? Did you have any contact with regional or national level coordinators or leaders?
Van Flandern:I think not other than the time that the Smithsonian sent one of their representatives to our team and sort of interviewed us to see how things were and what we were doing and how we were doing it. But other than for that, no.
Slabinski:My own feeling was I would not have felt uncomfortable or challenged or threatened that some woman was on the team, but none ever came along.
Van Flandern:It was a different society.
DeVorkin:Sure. I think we’ve covered your relationship with Tom Petrie. We wanted to expand on that a little bit from your initial responses.
Slabinski:He was more active at SOHIO Research I thought. He did a lot at Sohio Research I think.
Van Flandern:That’s right. Actually he visited us in Washington D.C. years later. He had moved to Oakland, California, I think, and had gotten into computers: little company he and a colleague had started called Thunderware. They made an early clock for the Apple and things like that, electronic boards. But that was the last I heard of him. That’s got to be probably 25 years or more ago.
DeVorkin:Well, we’ve pretty much finished the formal questions, but clearly you brought a lot of stuff, and if there are things that we should be covering that you would like us to document, certainly the stage is yours at this point. What have we missed?
Van Flandern:In the way of complete miscellaneous, almost unrelated miscellaneous, it occurred to me while we were talking about the old telescopes I have. I still have the Unitron and I think I still have the Dynascope in my basement, unless somebody threw it out. Something else I have in my garage is the very first East Coast delivery of a Sebring Vanguard electric car, vintage 1974. And it always occurred to me to wonder if the Smithsonian ever would be interested in such a thing. A Sebring Vanguard electric car — the first commercial electric car in the US.
DeVorkin:Amazing. The guys over in American History might well be interested. I don't think I could get that past my collection committee. But definitely anything of telescopes and astronomy related I’d be very interested to know because we do not have a Unitron in the collection. We don’t have a Dynascope in the collection, and I think it would be very useful. Do you recall if you got the very first generation Dynascope or the one that looked a little more like an equatorial mount? Is yours just a single stock, or does it actually have an axis?
Van Flandern:It has an axis, so I could set it up and point it at Polaris and have it then swing in the right plane. But it was just a tripod mount.
DeVorkin:Oh, yes. They were all very rudimentary.
Van Flandern:I was trying to puzzle it out in my own mind. I remember a black tube, and then I remember a bakelite tube, but I don’t remember if I upgraded or replaced the original or if I’m thinking of somebody else’s or what. I’m vague on that. The one I’m remembering that may or may not still be in my basement was the bakelite tube.
DeVorkin:Yes, that was the one that they made a big point of. The only other person I know who had one was Leroy Doggett and his widow has it. I think we would very much like to continue that, but that doesn’t have to be part of the interview. But you brought a lot of materials here. You brought the Warner and Swasey first generation instruments, and then one that you made yourself, Victor. For the record, what stimulated you to build your own design there?
Slabinski:Well, I still wasn’t a member of the team but I felt that if I was going to do anything I’d better have a Moonwatch telescope. I guess somewhere at that time I’d finally learned about Edmond Scientific and had bought the Erfle eyepiece and the objective lens and the first surface mirror. Then my problem was to find somebody who would machine an aluminum tube for me so these things would fit, and finally I learned that one of the priests in my parish who taught in high school had access to a machine shop, and he machined it for me so that the parts would fit. I had bought a book on satellite tracking, and although it was a pretty poor book I was expecting great stuff they told how to build your telescope there, and maybe I got the specs for the objects from there. I don't remember. But they also gave this design. That is a storm window hinge. They didn’t have triple track storm windows in those days. You took the screens down. You put the storm window up on the outside of your house, but if the weather got warm, you’d want to open up the storm window and you had these. Certainly that allowed me much greater ease in telescope elevation adjustment. This mounting was something I could make with my woodworking tools at home, saws and drills and things like that. Then on the other side of the telescope tube, there is a protractor with a plumb bob hanging down which gives you the elevation you’re looking at. I think my innovation was that protractor. Now the original design had just a flat board on the bottom, but after I built it the bottom board warped. So to prevent the warp, I put those two little crosspieces under the bottom to straighten it out. That actually worked out very nicely because in using it with the base off the ground, I could point the telescope north, put a protractor on the tabletop I was using in my backyard with one edge representing the north-south line, and then I could rotate the telescope over the protractor to get the azimuth I wanted. It was a very easy setup. I can do this even today if I just take a dining room chair out in the backyard, any flat surface; I know what azimuth I’m looking at just by starting off with the North Star. But optics-wise it is the same as the Warner and Swasey version.
DeVorkin:How did you end up with the Warner and Swasey? How did you end up with two of them in fact?
Slabinski:Well, the team must have had like ten or so. When it was down to me and the team leader, when I finally got registered with my backyard as a place I could observe from, I said to him, “Well, suppose I could convince some people from the neighborhood to join me in satellite observations. I need telescopes for them.” So he gave me two telescopes.
Van Flandern:In this article from the Cleveland News, April 12th, 1957, if you read that last paragraph there, it tells you a little bit about where the funds came from.
DeVorkin:I see. A fund of $200 donated by the News went toward the purchase of the lenses. The aluminum tubes for them were donated by Aluminum Company of America, and the machine work was contributed by Warner and Swasey. So these were not instruments that were cookie-cutter manufactured for national distribution; this was specifically for your team.
Van Flandern:That’s right. Following the design recommendations that the Smithsonian had put out.
DeVorkin:Exactly. They look just like the ones. And there is a question of what the original ones at the Smithsonian looked like. Some of them said they were exactly like that, but others said that they were M17 elbow telescopes in the very beginning. But then they went to this.
Slabinski:No, M17s came later.
Slabinski:Yes, they came later.
DeVorkin:Especially the ones with the 5” lens extensions?
Slabinski:You can read about that in the Moonwatch bulletins. They’re called apogee scopes because I guess they wanted to look at some of these high-flying satellites when they were at apogee, difficult to see. But you look at what this Warner and Swasey made, you see you have a limited range of elevation angles. Like you could lower the bottom end a little more, but you never could get down to looking at something on the horizon with that with the base level. My design gives me the full zero to 90 degree elevation.
DeVorkin:And you did it consciously for that purpose?
Slabinski:I think that was part of the design I got from the book. The book just gave me the concept, and probably as far as the exact way pieces of blocks got cut is probably my doing.
DeVorkin:When you had the Smithsonian design available, did you know that there was this limitation and it could be a potentially serious drawback?
Slabinski:Well, I think the Warren and Swasey probably made other telescopes of the series for specific elevations.
DeVorkin:Okay. They could have done that with just varying the separation of the two parts?
Slabinski:Well, I think the back piece could have been put higher.
DeVorkin:Did they actually put it all together then? In other words, they presented you guys with these samples?
Van Flandern:I don't remember.
DeVorkin:Because you acknowledge here there’s a $200 fund to get the lenses, and then the aluminum tubes donated by another company and then Warner and Swasey, I guess maybe, if I can construe that from here, it sounds like they put them together and that’s how you received them rather than the club making it themselves.
Van Flandern:That sounds right.
DeVorkin:Because they look too much alike. Every piece almost looks interchangeable.
Slabinski:I never saw the whole set of telescopes. I just received these two. So I have no idea what the differences would be. I just imagine that they would have been made slightly differently so that they could get down at lower elevation angles. Because that looks like you have a minimum elevation of 40 degrees, and you wouldn’t have limited yourself to 40 degrees in Cleveland.
Van Flandern:Probably not.
DeVorkin:Yes, but this one looks just like the example here. It sat at a completely different position though. By the way, I know this is posed, but did you guys feel a little silly holding the thing like that in that picture?
Van Flandern:I can’t remember that far back how we felt.
DeVorkin:I mean you look very serious.
Van Flandern:We were young, and the whole idea of press attention at that time was alien.
DeVorkin:Yes, it must have been. This was your first time that you were exposed in the media?
Van Flandern:I suppose, yes. For any good reason, yes. My sister had been in the news a lot years before, but that was not for a good reason. She was in a horrible automobile accident.
DeVorkin:They even gave your full addresses.
Van Flandern:It’s interesting. They used to do that all the time to identify people: so and so of this exact address.
DeVorkin:It is curious that for a company as well known as Warner and Swasey I must admit those are pretty crude. Was it because of expense do you think, or just expeditious?
Van Flandern:I think they were just following the recommended design.
Slabinski:They’re adequate. There’s no tracking on them because you didn’t do tracking.
Van Flandern:Oh no, nothing like that. There was nothing else quite there on the shelf that you could pick up that had such a wide field of view.
DeVorkin:But they didn’t put the Warner and Swasey name on the side.
Van Flandern:No, they didn’t.
DeVorkin:Do you know who actually contacted Warner and Swasey?
Van Flandern:No. There are a lot of things that are just gone from my memory. My wife is so good with details in the past. She can go into unbelievable detail of things of that era. I just have memories of the big picture.
DeVorkin:Were you married or you knew your wife-to-be throughout all of this time?
Van Flandern:Not all of it. I met her in 1962. I got married in ’63.
DeVorkin:And that was when you were in Cincinnati?
Van Flandern:’62 I was still there, and then ’63 had completed my first year at Georgetown and was in transition to Yale.
DeVorkin:I take it since you wanted to do orbit theory; Yale was the place to go?
Van Flandern:Yes. That’s right. It was a big school of celestial mechanics at that time. Brouwer and Clemence and Danby and Szebehely and lots of other people who were big names back then. Of course time passes, but you couldn’t know anything about celestial mechanics without knowing a lot of those names back then.
DeVorkin:I went there, but on the astrophysics side. I think I was about two years behind you.
Van Flandern:Yes. You know the story of how that happened?
Van Flandern:Well, after Brouwer died, the Yale review board met. They were trying to decide what to do about a successor to Brouwer. Yale had become the place in the world for celestial mechanics. So they went out to the review committees at the other universities, Harvard, Columbia, and all the others and said, “What should we be supporting in the way of astronomy?” They said, “Forget celestial mechanics. Astrophysics is where it’s at.” So they went from the world’s leading celestial mechanics school to an also-ran astrophysics… Looking back, from my biased point of view, that was not the smartest thing to do. Why do you go to your competitors when you’re trying to develop a plan for the future?
DeVorkin:The guy who was the chair of the advisory committee that did that was Spitzer, and he was actually an alumnus. By the late ‘70s, clearly it was very, very hard to see the continuing role for celestial mechanics. You were over on Edwards Street, and it was like day and night between the two places. You’re right. They had to reestablish themselves completely in astrophysics. There wasn’t any astrophysics there.
Van Flandern:That’s right. None at all in those years. They had a little radio astronomy.
DeVorkin:That was all gone by the time I got there. We knew Boris Garfinkle pretty well, and we always would go to all of his colloquiat because he was a fascinating, fascinating guy.
Van Flandern:He was fascinating to listen to, but boy could he wax enthusiastic about the most esoteric things.
DeVorkin:Oh, yes. But he had also attracted the historians who were interested in such things as Arabic speculation about the height of the atmosphere and atmospheric refraction. Because Garfinkle was the world’s expert on atmospheric refraction and stuff like that, as I understood it. It was a remarkable combination. I kind of wish I went to Yale a few years earlier.
Van Flandern:The heyday was great.
DeVorkin:You had better parties too. [Laughter]
Van Flandern:I believe we did.
Slabinski:I sometimes wish I’d been a year later in going through school, because after Sputnik went up, they started all these special programs to encourage students to go into science with all sorts of field trips and things. I never got to go on any of those special programs because I was already in college so they didn’t feel they had to recruit me anymore. But I would read about these programs they had for high school students behind me and wished I could have gone through some of those programs.
DeVorkin:So it’s pretty clear that both of you were not in a way recruited or drawn in because of Sputnik and the whole business; you were already pretty much dedicated and committed to it.
Slabinski:Two comments. I was interested in building rockets. That’s what I said I wanted to do. My uncle worked in an Injunering position. My father asked him, “What about rockets?” And supposedly he told my father, “Oh, guided missiles are the coming thing. Let the kid go off into rockets.” So my father was willing to let me go off to Case and study what I did. Who was running the satellite tracking program? Wasn’t [E. Micheal] Gaposchkin in there? They did a lot of analysis. He published papers in the ‘60s, didn’t he? Because I ran into him in later years, and whenever I’m in Boston we get together for a lunch or something. I asked him about those days, and he said that basically the satellite tracking program wasn’t sexy enough for Harvard — they didn’t feel that this was where they wanted to be. I kind of remember his name on things like SAO World Coordinate System II or something like that. I think if you checked the journals… I haven’t seen him for like four to five years, but I presume he’s still in the Boston area. I might still have a business card at home or something like that. He gave me encouragement on my LAGEOS work, the thermal thrust modeling. You were getting into electromagnetic things on planets. But that goes back to I guess I remember asking Jason Nassau, astronomy professor at Case something about celestial mechanics. Well, did they take possibilities, like electromagnetic effects into account? And he said, “Oh, yes, sure. They considered such effects [at least to put limits on].” What I learned later in life was: no, they hadn’t taken this into account, at least not to the level that you needed to put upper bounds. But back when I was knowledgeable of perturbation theory and things, no textbook would ever give you a reference well, so and so…
DeVorkin:LAGEOS was primarily geodetic, right? Laser, GEO dynamic Satellite
DeVorkin:So you were asking these questions when you were still a student?
Slabinski:No. This was just when I was an undergraduate student; just about planets. We all knew about the perihelion motion of Mercury as a general relativity constant. Whether there were other things. I forget the context very much, other than that yes, the professor was sure that these things had been looked at and now they wonder whether they really had or not.
Van Flandern:And the point was they weren’t?
Slabinski:At least the textbooks didn’t ever say, “Well, we know it’s all gravity to a certain level because Pointcare or Laplace looked into it.” Of course they couldn’t do it because electromagnetic theory hadn’t been developed.
DeVorkin:So you’re saying that classical astronomers like Jason Nassau simply assumed that all that stuff would be taken care of by somebody else, but not by astronomers?
Slabinski:It’s the case that when you’re not the expert you assume these things had been looked at. When you become an expert in a field you realize how much has not been looked at. When you’re not the expert, you expect the experts understand how this thing works and can give us an opinion. When you are the expert and someone comes to you, you know all the things that could go wrong and you sometimes can’t give an answer with the assurance that, say a politician wants.
Van Flandern:Jason Nassau and the story about the asteroid spectrum. Supposedly one day he was at his desk and a graduate student gingerly knocked, hesitant to interrupt him said, “Professor Nassau, I wondered if you could confirm the spectrum of this asteroid on this plate.” Nassau told him, “Stay right there. Hold the plate up.” He’s standing at the door. The student held the plate up very puzzled, and Nassau says, “G2 dwarf.” [Laughter] The student went away shaking his head, wondering how he did that. According to the story. Of course it’s probably elaborated a bit since the original. Who knows what his real reaction was.
Slabinski:That’s the Sun spectrum isn’t it?
DeVorkin:There are stories. Many years ago I interviewed W. W. Morgan, and he had a number of Jason Nassau stories. He said at the beginning, “I don't know which one of these is true and which ones aren’t true.” [Laughter] Okay, what are the materials then? We’ll call them exhibits of course.
Slabinski:Well, this is just kind of the evolution of the postcard orbital element service from Norton Goodwin. If you go to 824 Connecticut Avenue these days, you find there’s a high-rise building there instead of the townhouse that had been converted into an office building; he was up on the third floor.
DeVorkin:So I’m looking at one here from January 17th, 1964, and he’s sending you this stuff. You’re in Cleveland. It has a legend on the front of MPD, mean planar day, prime sweep interval, decimal indicators. These are all the types of units that you need. And then on the back, this is nominal elements for Echo II. So this is what you’d get from them?
DeVorkin:And you say that they changed over time?
Slabinski:Well, that was considered important to get out. It must have been newly launched.
DeVorkin:Are you giving these to us?
Slabinski:Are you asking for them?
DeVorkin:I don't know. Can we make copies?
Slabinski:I might give some of them to you. Here is 1960. These are not necessarily in any order.
DeVorkin:That’s an earlier one. This does not have the units on the front.
Slabinski:Because everything’s all spread out on the back. It’s when he started scrunching several on one sheet.
DeVorkin:Okay, so this is dated August 8th, 1960, and you had corrected nominal, modified orbital elements. And this is Echo. The same one? No. Echo II? Echo A11. Now Echo II… this is ’64?
Slabinski:1964 when Echo II was launched.
DeVorkin:That was when Echo II was launched, but this says Echo A11. That was just an earlier Echo?
Slabinski:Oh, it’d just been launched. See, NASA wouldn’t give a name to it until after it was successfully in orbit. That must have been known to the people developing it as the A11. Because they built a number of them.
DeVorkin:So here it looks like there are two different fonts. There’s a dark red font and a light red font. So is this a framework that they would fill in for each one of them?
Slabinski:I would say so. That’s a framework.
DeVorkin:Or did you send copies of these to Patrick McCray?
Slabinski:That wasn’t Moonwatch, so I didn’t send copies of that. They went through various names. First of all it was Phototrack, then he expanded more to Volunteer Satellite Tracking Program. But then later on he would squeeze several on a card. Here’s one from ’62 where trying to be current he includes Vostok III and Vostok IV, which apparently were in orbit at the same time, and says which frequencies they were using for voice communication, with the idea I guess that people would run off predictions and try to listen to them.
DeVorkin:And this was all for radio?
Slabinski:Well, for whatever. This was an early one. Now Echo A11 has become Echo I, and he’s trying to get people to do photographs for geodetic triangulation across the United States continent. Now remember, people have not successfully done photographic triangulation across continents. The Smithsonian eventually got into that.
DeVorkin:This is something that he simply initiated and maintained himself?
Slabinski:My understanding was he had a NASA grant for doing this. At least it paid for the secretary, because at some point he said, “I had to let her go because I didn’t have the grant anymore.”
DeVorkin:Okay. And this is dated August 17th, 1960.
Slabinski:Yes. Early August was when Echo I was launched.
DeVorkin:So would you say this was competing with Moonwatch or complementary to Moonwatch, or what?
Slabinski:He was providing a service. People wanted to go out and look at satellites and so they needed orbital elements, so he was providing them. It started as Phototrack. I went back to the library years later. This was very important for me. “Get thee to a marker.”
DeVorkin:“Get thee to a marker.” And this is from Kodak? This is from Scientific American volume 198, number page 43, January 1958. Swann of Eastman Kodak.
Slabinski:I wrote to them, and they sent me that.
DeVorkin:SPSE memorandum of 20 October 1957, information regarding Phototrack.
Slabinski:SPSE is Society of Photographic Scientists and Injuners.
DeVorkin:Okay, and this is three or four pages legal sized on the observations, establishing time coordinates, geographical coordinates, and this is all Norton Goodwin. He is the secretary/treasurer of Society of Photographic Scientists and Injuners.
Slabinski:He’s also a lawyer by profession, so I think he was also the general counsel.
DeVorkin:This is something for enthusiasts, but it’s really quite detailed. Interesting stuff.
Slabinski:This is where I started getting into real information, the way Tom would start with Sky & Telescope. This where I started. This was the first thing that told me where I could get orbital elements for a satellite.
DeVorkin:So it really didn’t come from astronomy. It came from this particular activity, whereas yours [Van Flandern] was more in astronomy, astronomy interests. How would you distinguish each other, let’s say, in terms of your own motivations?
Slabinski:He [Van Flandern] had the opportunity to make connections early on that I didn’t have.
DeVorkin:Would you agree with that?
Van Flandern:I guess so, yes. I don't know. We each gave the story of how we got there.
DeVorkin:I’m now getting you to talk about each other.
Slabinski:It’s accidents at birth, accidents of where you grew up. Just who gave you what for a Christmas present, so to speak.
Van Flandern:There is a lot of randomness, chance.
Slabinski:My uncle had a television set. He lived next door. I’d go watch the Nature of Things. Was it Roy K. Marshal, I think? It was a 15 minute thing on Saturday afternoon. I remember one time they talked about I presume it was ENIAC or something like this. They used this great big giant computer to work out the orbits of the planets. I listened to that and I said, “I’m good at math. Someday I want to work out the orbits of planets.” But it wasn’t “Write away to Sky & Telescope” or “Write away to Smithsonian and get them to list you for Moonwatch” or something like that. All this stuff was out there. I was getting this stimulation. I was learning about things, but I just never quite made a connection with a Moonwatch team. Also I would say my age was such, I was too young to drive but my parents wouldn’t take me out there. When I finally got my driver’s license, “5:30 in the morning to go to Lakewood to watch a satellite? When you grow up, you can go do that kind of stuff.”
DeVorkin:That was sort of what I was asking before. How did your parents feel, you going out all times of night to another part of town? You answered, though, ‘you did it all in your backyard.’ Is that why? Because your parents really didn’t want to take you across town at 5:30 in the morning, which I can understand?
Slabinski:Well, finally when I was old enough and they were a little more lenient about me using the car, there was no Lakewood Park observing site to go to at 5:00 in the morning. Besides, my father would need the car at 5:30 to go off to his job at Thompson Products. There’s these postcards. Later on, he went into gear ratio elements. It’s just a different format that packed a lot of things into —
DeVorkin:This looks like a totally incomprehensible piece of paper.
Slabinski:True, but the thing is he has packed a lot of data there, and he was very concerned with ‘how much can I pack in before I exceed the post office limit on what I can put out for a minimum stamp’?
DeVorkin:Current gear ratio elements. What is a gear ratio in this case?
Slabinski:It was a concept that you had gears so as the satellite went around the gears turned and it changed the elements of the orbit. The perigee moved and the node position moved. It was completely unnecessary; bringing in a Ptolemaic system.
DeVorkin:On the bottom it says Independent Tracking Coordination Program. That’s what he ended up calling himself?
DeVorkin:It’s remarkable. This is 1965. I don't know if I’d ever be motivated to try to read anything like this. So it takes a very definite type of person to do this. We’re of course more interested though in the Moonwatch stuff itself. What kind of materials did the Moonwatch people send out, and what was most helpful to you and what was least helpful to you?
Slabinski:Well, myself, latitude crossings would have been very helpful, but you never could get that sheet you’re looking at from the team leader. This was what the report form looked like.
DeVorkin:“Official Moonwatch report.”
Slabinski:At some point they would put out a list of satellites and tell you what you were looking at.
DeVorkin:Size characteristics of objects in orbit.
Van Flandern:It’s been a long time since I’ve seen one of those.
Slabinski:I don't know where I got this form, but that’s number one.
DeVorkin:A lot of these came with Sky & Telescope as I recall as a kid. Weren’t they sort of interleaved sometimes?
Van Flandern:Yes, that’s right.
Slabinski:Oftentimes they were the centerfold and they were stapled in. At some point someone was selling his back copies of Sky & Telescope and I went and bought the ones before where I had started subscribing. I finally started subscribing in ’62 when I went to University of Maryland and the joined the National Capital Astronomers. If you joined and paid dues for membership you get Sky & Telescope as part of it. Oh, that’s a great deal. So I paid my dues right there. But anyway, here are numbers 10, 11, 12. Time of ’61 omicron IV breakup determined. So here is August 21st 1961.
DeVorkin:I’m looking at the National Advisory Committee list of people. You mentioned Steadman Thompson. That was the person that you guys had contact with?
Van Flandern:I did.
DeVorkin:Because he was in Columbus.
DeVorkin:So you were encouraged to write to one of these people.
Van Flandern:He was the designated point of contact for the state of Ohio.
DeVorkin:Interesting. I wonder how you would go about figuring out how these various people were identified and chosen, but probably I would guess it would be through the amateur networks at that time. Is that possible?
Van Flandern:Could be. I never knew.
Slabinski:I would suggest you look through the stuff from the Astronomical League that I sent to Patrick McCray. Because it was quite clear in reading through that. I had gone to the Naval Observatory Library and they had a very complete collection of the National Capital Astronomer newsletters and I went through them. Because Bob Wright was from National Capital Astronomers. He lived in Silver Spring. He’s the head of that committee there. I figured ‘what could we learn by going through that?’ The Astronomical League, was pushing this Moonwatch thing. It said, “This is probably the most important thing the Astronomical League will ever do.” People say they recognized very early on that ‘hey, we’re going to be part of something big here.’
DeVorkin:Did anybody ever say, “But this isn’t astronomy.” Or “how is this astronomy?”
Slabinski:It was out in space. It was outer space. Outer space was above the atmosphere.
DeVorkin:So is that what the fascination is, that it’s something in space?
Slabinski:I think in that time in popular imagination astronomy and space were pretty close. Now I could say, for instance, among our professors at Case that originally these postcards were going to the astronomy department at Case. I would call up the professor who got these and I said, “Could you read me the orbital elements for this week?” After a couple of readings of those, he said, “Why don’t you write to this guy and have him send them to your home? We never use them.” His comment was, “Satellites are like asteroids. I’m glad somebody takes care of them, but there’s just too many.” Another time it was kind of comment sneering about lawyers who do satellite tracking.
DeVorkin:A comment on Norton Goodwin. Yes, sure. This was the elite view of the astronomers for all of this at the time. Certainly it’s reflective in your comments about the change at Yale. I don't think there was anybody in the astrophysics group interested at all in the visible sky.
Van Flandern:Right. In the ‘50s and early ‘60s, there wasn’t such a field as space science. It was all just astronomy or you were dealing with something on the Earth.
Slabinski:Myself, after my year at Maryland, I went back to Case to visit a professor there. I had not done well at Maryland. I said, “What should I do?” He was willing to take me on as a graduate student. He said, “I know you don’t want to do physics. I know you want to go out and build satellites and all this. But I’d like you to get a good solid training and then go do what you want.” His example was: “Bridges are built four times stronger than they need to be because nobody knows how to calculate them well enough to come closer to the limit.” That was his opinion. I’ll train you to be a good physicist and then you can go and do things intelligently. Herman Michielsen. He was the guy who wanted observations of these Agena rockets. I presume he’s dead now. I last visited him in the late ‘70s and he was pretty old.
DeVorkin:This is an article from Photographic Science and Injunering, volume six, number six, November/December 1962: “The use of medium accuracy observations for orbit studies of artificial satellites”. Here he’s making a very interesting statement. “Because Baker-Nunn cameras are expensive, their number is limited; and although satellites are even more expensive, they outnumber Baker-Nunn cameras to such an extent that even an approximately complete tracking program for all satellites cannot possibly be managed with Baker-Nunn cameras alone. Hence to cover the bulk of satellite recording, less accurate observations must be used.” Is that the rationale here?
Slabinski:Well, he had told me that he hoped to get an Air Force grant or had gotten the Air Force grant to study this, so he was looking for his own research interests there. It’s an interesting paper. What he’s telling you as the isolated observer: which are the useful observations. For him the useful observations are if tonight — He was talking polar orbit satellites, and you’re talking low altitude. So if the satellite is in a polar orbit at low altitude, you get maybe one pass a night. Or at least on each leg. You don’t get multiple passes. So he’s saying if the satellite passed to the west tonight, so you’re looking like this, and you can only observe one more time during the next couple of days, get a pass where you’re looking toward the east so that basically you’re looking at the satellite orbit from two very different directions so that we can pin it down. From your two observations we can pin down that leg of the orbit very accurately. And he explains how that works. He may have something in there. One very accurate observation is better than two mediocre observations on the same pass.
DeVorkin:Did this program build on Moonwatch, or was it completely independent of Moonwatch?
Slabinski:I’d say it’s independent of Moonwatch. But I would say people who have been active in Moonwatch were probably on his observer’s list. Myself, I went through the list there; I ran across it a number of months ago. When I saw names I recognized, I wrote to them and said, “Hey, did you do Moonwatch? Get in contact with Patrick.”
DeVorkin:Oh, very good. That’s extremely helpful.
Slabinski:Now I never thought to contact everybody on that list. Again, that’s a very old list back from the ‘60s, 40 years later.
DeVorkin:Did you send Patrick this material?
Slabinski:No, I didn’t. In my material to him I talked about Michielsen and in my questionnaire I had an appendix about other tracking programs and I talked about this, because it was very important to me because this is what I participated in. I just said this list was here and this was just my stuff.
DeVorkin:It’s good to know about these things. I think as if not offshoots, certainly complementary programs that followed on. I’m most interested in that because I’m interested in the Baker-Nunns, to follow up the history of the Baker-Nunns and their effectiveness. I see you have an awful lot of stuff here.
Slabinski:Well, I also have stuff on Project Oscar. My brother was in amateur radio, so, “Hey, Chet, let’s go listen to the satellites.”
DeVorkin:All of this material would eventually be very valuable, I think, for accession in an archive to be able to fully preserve this history.
Van Flandern:I have one more Moonwatch remark. I had mentioned I had just heard from Dennis Smith last week. A remark that he made in that conversation I think bears repeating. He said he isn’t sure about all the activities that youth engage in today, whether they’re playing video games or out doing drugs or whatever, but back then when we were teens, we were very actively engaged in this. We had the feeling that we were doing something productive for society as well as learning lives and careers for ourselves. For that reason alone, operation Moonwatch was a wonderful thing to happen.
DeVorkin:That’s a very nice statement. He said that to you in conversation?
Van Flandern:Yes, last week.
Okay, so I can’t find it in a piece of paper. So it’s on the record here. That’s very good. I want to thank you for the time. Just for the record, this will be transcribed, and I’ll do a first edit and then I’ll send you the transcription for your comment. At that point you can add information or correct information or take it out or whatever. Then we ask you to sign a literary use form, how this can be used.
 Sputnik 1 and Sputnik 2 and Explorer 1
 Journal of Geophysical Research. JGR 70, 3131 (1965)
 J.A. O’Keefe, Ann Eckles, and R. K. Squirei, “Vanguard Measurements Give Pear-Shaped Component of Earth’s Figure” Science 129 [no. 3348], 565 (Feb. 27, 1959). Theoretical Division NASA Goddard
 The Warner and Swasey Company was an important machine tool manufacturer in Cleveland, Ohio. Mr. Warner and Mr. Swasey were amateur astronomers. The company built the mount for many large telescopes in the early 20th Century. They donated the Warner and Swasey Observatory to Case School of Applied Science.
 The Cleveland News was a daily newspaper.
 I showed David a reporting form here — Slabinski.