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Oral History Transcript — Dr. John Salisbury

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Interview with Dr. John Salisbury
By Richard Hirsh
At Center For History of Physics
July 27, 1976

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John Salisbury; July 27, 1976

ABSTRACT: Topics discussed include: research with x-rays and the moon; American Science and Engineering, Inc. (A.S. & E.); National Aeronautic and Space Administration (NASA); geo-thermal and geophysics space research; astronomy.

Transcript

Hirsh:

How were you connected with A. S. and E. or how did you make contact with them?

Salisbury:

Well, many years ago Riccardo Giacconi came in to do research — the center at that time it was called — and made a proposal. And the proposal was to make a compositional analysis of the moon, using it for fluorescent x-rays. At that time the solar wind was blowing up a storm. You know, the estimates of the strength of the solar wind were very high, and so it seemed reasonable that this could be done. So we financed the building of very large detectors and a rocket package, and by the time that the rocked was finally launched we realized that the solar wind was not as strong as had been initially supposed, and one really would have been surprised to see lunar x-rays. However, we gave it a try and lo and behold there was a x-ray source. For a while we thought it was the moon, too.

Hirsh:

It seems like it took a lot of convincing before you realized that it was a non-lunar source.

Salisbury:

Well, yes. Nobody expected a non-lunar source. It was totally unexpected. And the source was close to the moon, so that was part of the confusion. The sources were in the same part of the sky. As I remember the plot, it was plotted like 20 degrees away from the moon. Now, you know, one is tempted to…When you do an experiment like that, you figure probably your plot’s off.

Hirsh:

Right.

Salisbury:

Because 20 degrees…I mean it if had been 180 degrees away, why that would have been something else. But it was pretty close to the moon, and so we thought it was the moon — for a while. You know, we wondered: what the hell? And then I don’t know who… I don’t remember who suggested it was a star, but it was probably Ricardo; and so they weren’t ahead and wrote their paper.

Hirsh:

Why did Chicano go to you or why to the air force in particular?

Salisbury:

Well, the Air force had a space program at that time. As you know... I mean for a while the Air Force was going to join to have a lunar base and things like that, right? And we were co-located, I guess. That’s a big reason.

Hirsh:

How was that?

Salisbury:

Well, their company was in Cambridge; and although our company was no longer in Cambridge, we were just out on 128 and so it was easy for them to come talk to us. You can ask Ricardo why he came to us. I don’t really know.

Hirsh:

I see. Do you know what happened in between, like the first proposal and first rocket shot? You said that the estimates of the solar wind decreased, I suppose. Do you know who was involved in making those new estimates or the new research that was done between?

Salisbury:

Gee, that’s too many years ago. I couldn’t tell you for sure. I’m trying to remember when that was. Actually the rocket shot itself was 24 October ’61, I believe.

Hirsh:

That was not much of a success, though — the first one.

Salisbury:

Well, it detected x-ray. That’s the one that detected it first.

Hirsh:

I think that was the June ’62 rocket. I think the first one blew up of something? Is that possible? Something happened.

Salisbury:

Well, the reason I know the date is I have the tip off the rocket on my desk here. And it says on the side or it, you know, something about x-ray first detection and 24 October ’61, but I might be mistaken. The program stretched on for a while. I know we did have… I remember now. The first rocket: that was the blow out. That was the malfunction.

Hirsh:

I see here: I’m looking at Giacconi’s account – he says, “First rocket flight in October ’61 failed to give results because of the malfunction of the nykeeast (?) rocket engine.

Salisbury:

That’s right. But I sure have a nose cone here from it. But I do remember on rocket failed because the [???] didn’t blow out. When does Ricardo say that he first discovered x-ray?

Hirsh:

’62, June 12th.

Salisbury:

Is that right?

Hirsh:

Yes.

Salisbury:

By golly. Well, he should remember.

Hirsh:

Yes.

Salisbury:

When was that written?

Hirsh:

This was written in ’72, I believe — this account that he wrote — although the paper in which he announces the discovery of x-rays came out in December, ’62, and he refers specifically refers only to the June 12th, ’62 flight and not the October, ’61.

Salisbury:

Okay, well, I give up. I’m basing it all on this note because my memory sure doesn’t stretch back that far.

Hirsh:

Well, there were apparently detectors on the first one, on the October flight.

Salisbury:

Oh, yes.

Hirsh:

But nothing happened.

Salisbury:

Yes. Well, there was a malfunction. I can’t remember for sure, but I thought the door didn’t detach. Anyway, ultimately success.

Hirsh:

Yes, ultimately. Do you remember when they made their first proposal to you?

Salisbury:

Oh, gosh, it must have been about 1959.

Hirsh:

Yes.

Salisbury:

It would either be the winter… It was the winter of ’59-’60, sometime in there.

Hirsh:

I see, because there seems to be a little problem here. Apparent A.S. and E went also to NASA and asked for support and NASA refused support. They didn’t think the X-rays coming from the moon would be detectable near the earth, and they were right.

Salisbury:

Yes.

Hirsh:

That shouldn’t have stopped them.

Salisbury:

Oh, I don’t know. Why not?

Hirsh:

I said that a bit facetiously.

Salisbury:

I mean who remembers history that well anyway? As far as I remember, the calculations, which showed that they were just barely detectable were very large detectors, mind you, did depend on a solar wind that was a little stronger than it turned out to be. That’s my memory, and I’m the guy that thought the rocket was in ’61.

Hirsh:

Right. And what happened after the ’62 flight or the flight when they did detect x-rays? I know the Air Force supported four flights all together.

Salisbury:

Yes, sure. We wanted to continue to support Ricardo’s work. As I remember… I mean obviously there was no longer a lunar interest, but NASA didn’t pick it up. So if you want some gossip, for a while there — who’s that guy at NRL?

Hirsh:

Friedman?

Salisbury:

Friedman, yes. Friedman was standing around and saying, “Oh, bullshit, bullshit. If there were such a thing, I would have detected it.” And I think that they may have… Anyway they couldn’t get support elsewhere, and we had funds in hand to support them, so I went on. I kept supporting them anyway, because I thought…well, you know, the work was important. But ultimately they did get NASA support, and then we handed the [???] over.

Hirsh:

I see. So you were in effect waiting for someone else to support.

Salisbury:

That’s correct. Well, I couldn’t justify it under my program. You know, it was just one of those things that one kind of bootlegs.

Hirsh:

Do you remember how much money was spent on these projects?

Salisbury:

Gee, not really. It was a $100,000 a year sort of a thing. Things didn’t cost that much in them there days. The rockets were free to my program, so I’m not counting the cost of the rockets.

Hirsh:

I see. Where did they come from?

Salisbury:

Well, they were part of another cost. But even so those little rockets weren’t expensive.

Hirsh:

That was a real bargain, I think at least, considering the scientific information that they got from them.

Salisbury:

Yes, the importance was well worth it. We had some fun in those days. Every once in a while we had to go through some contortions. I remember that at one point there was a squeeze on overtime, and we’d spent all this money to put the rocket together and had the rocket, the nose cone and all that all ready to go, and the President said, “We’ve got to minimize overtime.” Some idiot down there in white pants decided to minimize it, and to minimize was to have zero. I mean that was the minimum that you had. And we wanted to shoot the rocket at midnight or after dark naturally, and that meant that if we were going to fire we had to have overtime, and so they couldn’t do it, and so I shipped the rocket to Canada, and the Canadians fired it under contract for us because they didn’t have to worry about overtime.

Hirsh:

So that must have cost more than the overtime would have cost.

Salisbury:

Of course. It cost us $47,000, as I remember, to get this thing blown out of Canada.

Hirsh:

That’s incredible.

Salisbury:

But at least we saved overtime.

Hirsh:

There was no other advantage in shooting it from a more northern position?

Salisbury:

None that we knew of at the time.

Hirsh:

That’s incredible. But that wasn’t the first flight, as I remember.

Salisbury:

No, that was the last flight, as I remember.

Hirsh:

I see. That’s a great story I must admit. That’s tremendous. I know you’re known at URDA.

Salisbury:

Yes.

Hirsh:

Would you still have any of these papers of proposals sitting around anywhere?

Salisbury:

Oh, good heavens, no.

Hirsh:

Because I’m having problems getting things, especially the A.S. and E proposals. They made some for NASA, and NASA should have them, but they went through a routine destruction.

Salisbury:

Of course. I mean all that stuff, those papers…

Hirsh:

I’m trying to pick some of these papers up at the other end of the line if possible, but it doesn’t look too hopeful right now.

Salisbury:

Yes, the Air Force… We probably stored it some place, but they put this stuff on microfilm ultimately, I guess, but not proposals — surely not.

Hirsh:

Is there any way I can get some of these? If I call up someone at the Air Force, would they be able to find them for me?

Salisbury:

Boy, I don’t know. Yu know, maybe there’s an archivist or something, but I wouldn’t have any idea.

Hirsh:

You wouldn’t know anyone I could call over at Air Force CRO?

Salisbury:

I couldn’t give you a name that would be interested in something like that. I guess I can give you the name of the guy who might know about… I’m trying to think who would be the most… Well I’ll tell you the guy who would be the most interested in helping you would be Henry Novack. That’s area code 617-861-3162. And he’s attached to the office of the chief scientist there, and he was at one time in our information office, and, you know, he digs history and historical events and all that sort of thing. So if anybody could help you, he could.

Hirsh:

Good. Well, a contact anywhere — it’s better than the operator there.

Salisbury:

Yes. I recognize that.

Hirsh:

And that’s what I’ve been getting. It was quite a chose finding where you were right now. I had to go through quite a hassle in order to find out you were right here in Washington.

Salisbury:

Well, you can tell Henry I suggested that you talk to him as the most knowledgeable fellow around. Lay it on a little thick. He’ll love it.

Hirsh:

Okay, very good. Could I ask you what you’re doing now?

Salisbury:

I’m in energy research, as you know obviously, but geo-thermal. My background is as a geologist. I got my Ph.D. in geology, and I got into a study of the moon and planets from the geological end of it, although we wound up using a lot of geophysics to do these studies. Well, the new frontier is energy — I guess.

Hirsh:

Yes, I see. And what is your position there at URDA?

Salisbury:

Chief of the research and reservoir assessment branch. It’s the geo-thermal energy division.

Hirsh:

Right. So you’re totally out of space science now.

Salisbury:

Yes, totally out. But, you know, still interested.

Hirsh:

Right. It seems to me that most of the people who got into space science were not astronomers at all.

Salisbury:

That’s right.

Hirsh:

That’s something that surprised me at first. Would you care to venture why that might be so?

Salisbury:

Oh, yes. The moon was not respectable as a subject for study in astronomy. Early on it had that, but somewhere around… when?... was it 1900, 1911? They invented the spectrograph.

Hirsh:

Right. Well, it was a little earlier.

Salisbury:

Well, anyway it was applied to astronomy. I guess they got appropriate instrumentation of plates and so forth they could put on a telescope, and once they did that, of course, they could look at stars. And so astronomy became totally stellar. But prior to that time, it had been very interested in the moon and planets, but it became totally stellar, and it was a snob sort of a thing. People who were concerned with the moon and planets weren’t really astronomers, and as a result… I mean the few who were were considered oddballs. So that when the interest in the moon and planets rose, why the manpower in astronomy was not available for the job. And they maintained that attitude, too.

Hirsh:

Even after it became more fashionable, though.

Salisbury:

Well, yes, I think so.

Hirsh:

It’s just something which when I started doing work in x-ray astronomy, I expected to be in contact with astronomers, and all I’ve been talking to are physicists and geologists and so on. It’s quite remarkable in a way. It’s obvious to people who are in the field, but to those of us not specially directly related to these fields, it was a bit of a surprise. Well, I think that winds up my questions. Thank you very much. Let me ask you this finally: would it be all right to quote you in something you might have said in my work?

Salisbury:

Sure. Quite it grammatically even if I wanted.

Hirsh:

Indeed. I’ll underline it or put it in italics. How about that? And finally I’m working in conjunction with Spencer Weart at the American Institute of Physics, who is trying to build up archives in the history of astrophysics and astronomy, and he asked me whether it would be possible when I made these tapes if I could deposit the tape with him for use by other historians for scholarly purposes. Would that be all right?

Salisbury:

Sure.

Hirsh:

Okay. Well, tremendous. I really enjoyed talking with you.

Salisbury:

Okay. If you ever got to study the history of our exploration of Mars, give me a call back, because I was involved in that quite a bit.

Hirsh:

Well, there’s someone else working here in the history office who’s looking at the… is it the explorer, the p[predecessor of Viking?

Salisbury:

I’ve forgotten myself. Whatever.

Hirsh:

She’s working on how Congress got advice on these Mars probes, and it seems like a lot of the advice came from NASA, and then that would go to Congress, and Congress would vote on how much money to give NASA. It seems a bit circular. But she’s definitely into this Martian research, and maybe I will have her call you if that’s all right.

Salisbury:

Yes, well, I wasn’t involved in the funding, but I was involved in the development of some of the ideas and concepts of Mars. A lot of people would like to rewrite history, but that particular history I participated in as a researcher, not just as a source of funding as I did with Ricardo, and I would like to have my crack at… You know, the early view among astronomers was that the surface of Mars was covered with limonite. Have you ever heard of the limonite soil?

Hirsh:

No, I think I missed that.

Salisbury:

Well, the red color of Mars suggested ferric oxide, and Dolfus over in France did some polar metric work and he said the polarization characteristics of the surface is identical with ferric oxide with limonite, which is a ferric oxide with mineral. Actually the word “limonite” is kind of a garbage term. It included several minerals typically — hematite and getite. It’s a mixture. Never mind. Ferric oxide hydrated ferric oxide. So it was popularly assumed that Mars was covered with a soil composed of limonite, and this seemed fine to astronomers and physicist because they didn’t understand geology at all. So in 1964 I wrote a paper which said this is total bullshit. First of all, it’s impossible geologically for the surface to be covered with ferric oxide because that implies a composition of the planet that’s ridiculous, because what happened to all the other material? And you can have a ferric oxide stain on things that makes them reddish but the bulk composition has got to be that of all silicates, just as it is on the earth. And oh, I got into a lot of difficulty, because this was gospel at the time and believed by all sorts of a thing, including Sagan. And Sagan and his offside (?) there who’s now at Ames — they wrote several papers. And Sagan is really such a terrific speaker. You know, I had said that you could have a soil which would have a silicate particle which is coated with ferric oxide stain, right? That’s how I explained the color. And Sagan got up and put me down terrifically, that “this does not provide a very striking economy of hypothesis.” And of course you’ve heard of Occum’s razor, and indeed, it did provide an economy of hypothesis to say that the soil was entirely pure ferric oxide. But it wasn’t reasonable geologically. And so I had a more complicated hypothesis, which was nevertheless correct.

Hirsh:

Right. Well, that why they found last week, right?

Salisbury:

Sure. Of course.

Hirsh:

Tremendous.

Salisbury:

And oh Sagan just got me to ribbons because he’s such a good speaker. But wrong he was, and he persisted in it for years, for years. And my co-author and colleague, Graham Hunt and I, wrote paper after paper using first divisible and near infrared and then the mid infrared, saying no, it is not, it could not be, cannot be. You know, we did spectroscopic remote sensing of the surface. Indeed it is a silicate coated with ferric oxide, and finally we concluded that the dust was a montrilinite(?) clay in the dust storm. Anyway that has a long history, and there were a number of people from Balthus through Don Ray to Carl Sagan who were on the other side of the fence.

Hirsh:

Tremendous.

Salisbury:

So one day I hope to put that record straight.

Hirsh:

Well, you know, you might had the chance. Carl Sagan is coming to speak at NASA on August 4th. I don’t know how your schedule is, but it you’d like to come over, that would be fine. They have a few lectures here since I’ve been here at least, and they get a good turnout. They next talk by Sagan has been publicized a bit. He’s supposed to talk about is there life or intelligent life on Mars.

Salisbury:

Right.

Hirsh:

So, again, I don’t know how your calendar is, but you might find it interesting to needle him from the crowd.

Salisbury:

Oh, I wouldn’t do that though. I mean Carl’s a fine fellow — overbearing at times but still a brilliant fellow whom I admire, and I wouldn’t needle him from the crowd. Besides I’m sure that in a needling contest I would lose, but I wouldn’t do it anyway.

Hirsh:

Okay, but again he is going to be here August 4th.

Salisbury:

Well, good. Well, if you see him, please give him my regards.

Hirsh:

Okay.

Salisbury:

And you can ask him about ferric oxide on Mars. Ask him: “What is the history of this limonite controversy anyway?” (laughs) See what he has to say.

Hirsh:

Great. Okay, well, thanks again. I really appreciate this and it’s been a pleasure talking with you.

Salisbury:

Yes, indeed.

Hirsh:

Okay, bye-bye.