Interview with David S. Heeschen

David S. Heeschen, 1926-2012. Interviewed 28 December 1973 at NRAO in Charlottesville, Virginia, length of interview: 47 minutes.

Papers of Woodruff T. Sullivan III

NRAO/AUI/NSF

Oral History

Sullivan, Woodruff T., III

Heeschen, David S.

Audio cassette tape

47 minutes

1973-12-28

First HI work on 24 foot Agassiz dish and some on 60 foot dish; 1956- at NRAO; 85 foot Tatel dish, all the problems of the 140 foot construction 1958-1965 (good info), NRAO philosophy, 300 foot construction; not very much on early research done at NRAO.

The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of Early Radio Astronomy (Cambridge University Press, 2009) or was transcribed in the NRAO Archives by Sierra Smith in 2012-2013. The transcription may have been read and edited for clarity by Sullivan, and may have also been read and edited by the interviewee. Any notes added in the reading/editing process by Sullivan, the interviewee, or others who read the transcript have been included in brackets. If the interview was transcribed for Sullivan, the original typescript of the interview is available in the NRAO Archives. Sullivan's notes about each interview are available on the individual interviewee's Web page. During processing, full names of institutions and people were added in brackets and if especially long the interview was split into parts reflecting the sides of the original audio cassette tapes. We are grateful for the 2011 Herbert C. Pollock Award from Dudley Observatory which funded digitization of the original cassette tapes, and for a 2012 grant from American Institute of Physics, Center for the History of Physics, which funded the work of posting these interviews to the Web.

Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.

Working Files Series

Individuals Unit

Transcribed for Sullivan by Bonnie Jacobs.

Sullivan

Can you tell me where you began?

Heeschen

I can try and describe the way the 21 cm line group at the Harvard Observatory began. At least by recollection of it and I don't remember the exact date, you should talk to Campbell Wade, but Campbell Wade came back from the Army as an undergraduate. He'd interrupted undergraduate to go in the Army. When he came back he was interested in the then new observation on [Harold "Doc" Irving] Ewen and [Edward Mills] Purcell on the hydrogen line. And he went over to see Ewen at the Harvard Physics Department and wanted Ewen to teach him how to use the equipment that Ewen had built to detect the line. And at that time nothing further was being done in observing. So Wade wanted to learn to use it and then make some observations.

Sullivan

This is sort of precocious for an undergraduate, isn't it?

Heeschen

I don't know. Anyhow, he wanted to do that. And Ewen was quite happy to but he didn't feel he was prepared to take the time to teach just one undergraduate. So he approached [Bart J.] Bok and why he approached Bok I don't know.

Sullivan

Bok was already there as an optical astronomer?

Heeschen

Bok? He'd been there since 1932 or something. Not '32 but he'd been there a long time as an optical astronomer.

Sullivan

Well, that's right. He didn't go to Australia until afterwards. That's my mistake.

Heeschen

As a matter of fact he had been there since the early 30s. So I don't know whether Ewen went to Bok or whether Wade went to Bok but anyhow, Bok then approached Ed [A. Edward] Lilley and myself, who were both graduate students at Harvard at the time. And I don't know why he approached Ed but I suppose he went to me because I'd been fooling around a little bit with amplifiers for [???] and was the only one Bok knew had any interest in electronics apparently. And wanted to know if we were interested and we said we were. So then we and Cam learned to use Ewen's equipment.

Sullivan

The same horn?

Heeschen

The same old horn and stuff all set up in Lyman Lab and Doc Ewen showed us how to use it and so on. Then announced that receiver was going to go Merle Tuve’s group at NRL [Naval Research Laboratory] and wouldn't it be nice if Harvard got a new receiver.

Sullivan

At DTM [Department of Terrestrial Magnetism] you mean, I think.

Heeschen

The DTM, ok. No as a matter of fact it was to NRL, it was to John Hagen - I'm sorry maybe it was to DTM. Anyhow, that receiver was going to go somewhere.

Sullivan

When was this?

Heeschen

It must have been 1952 or '53.

Sullivan

A year or two after the initial discovery?

Heeschen

Yes. Ewen then said, Ok - Actually I'm not sure any more of the sequence but the net result was that Ewen formed Ewen Knight Co., built a receiver for Harvard, and at the same time built a receiver for NRL. Those were the first two jobs for the Ewen Knight Corporation and it was incorporated for that particular job. Then Ewen said that the horn wasn't big enough and shouldn't we have a bigger antenna. He proposed to Bok that Harvard get a bigger antenna. And at that point they did and I'm not familiar with how Harvard - how Bok contacted DS Kennedy Company. I think it was through Bob Grenzback, who was a friend of Doc Ewen's and who was the Chief Engineer for the Kennedy Company. Grenzback and Ewen had been associated on with some project with regard to the Harvard cyclotron, I believe. The net result was that Harvard wound up with a 24 foot dish.

Sullivan

Kennedy hadn't made reflectors before, you mean?

Heeschen

Yes, they had been making reflectors. I believe so. In any event- I'm pretty sure they had. I think they were making military reflectors. Anyhow, Harvard wounded up getting a 24 ft dish from Kennedy Company and a receiver from Ewen Knight Corp. And Ed Lilley and I were the two graduate students involved in this. We did all the wiring, a little building was built out at Agassiz Station at Harvard. And we, with Doc's technicians, and so on helped install the receiver, install the antenna and do various things. For example, I can remember renting a truck and Ed and I picked up the polar axis from wherever it was being fabricated in downtown Boston and drove it in a rented truck up to Agassiz Station. And this was sort of a graduate students’ project.

Sullivan

Was there any other research done with the horn other than the initial detection?

Heeschen

Not to my knowledge.

Sullivan

So you just sort of learned how to operate but then did nothing with it?

Heeschen

Yeah. I don't recall ever - we never did any observing with it at all. I think the receiver itself was dismantled and sent to wherever it was sent - either DTM or NRL - very shortly after that. The receiver was pretty much a haywire rig that had been thrown together.

Sullivan

I've seen pictures of it.

Heeschen

His new receiver was patterned more or less after the old one with a lot of refinements that had occurred to him as a result of building the first one.

Sullivan

Why was it that this didn't get followed up at Harvard until really the Agassiz dish was built?

Heeschen

I don't know. I have no idea. Since it was followed up within a year or two...

Sullivan

Right. There was just sort of a gap there.

Heeschen

Yeah. It was a graduate students’ project remember. I don't know why.

Sullivan

I'll have to talk to Ewen about that, I guess.

Heeschen

Or Bok or the people in the Astronomy Department.

Sullivan

Except was it in Astronomy or was it in Physics?

Heeschen

It was in Physics but you wouldn't have expected the Physics people to follow it up.

Sullivan

Well, that true.

Heeschen

Since their interest was more in the equipment and the technique, I think, than in the astronomical observations that would ultimately follow.

Sullivan

Right. And then nuclear physics of the line transition and so forth.

Heeschen

Right. The first programs done with the 24 foot dish were Lilley's and my theses and we divided the time up between us - 12 hours a day each for, I don't know, some long period of time, which we did observing for the theses. And then a lot of people followed after that, a whole string. And a year or so later, again I'm now a little vague on dates, but it must have been in 1954 or so, that Bok got money for the 60 foot dish and contract with Kennedy for that. That got built and started operations in about 1955 or '56.

Sullivan

Your thesis was done wholly on the 28 foot?

Heeschen

No, 24 foot.

Sullivan

Can you just say a little about what it showed or what its main results were?

Heeschen

Mine was on the distribution of hydrogen in the general region of the galactic center and it showed the broad scale structural features in that region as they can be seen with a dish that has a rather poor resolution and a rather poor, compared to today, frequency resolution as well as spatial resolution and not such good sensitivity. The receiver noise temperature was, if I remember rightly, about 1000°, maybe it was 800°, and the dish was a 24 foot dish. So you can compare that with the 100 meter dish and a 50° temperature system and there's a huge change in sensitivity since those days. In fact, it’s really remarkable the way sensitivity in that particular area of research. The thesis showed, for example, there was a correspondence between the hydrogen distribution in Gould's Belt in the region of the galactic center and also Lilley found this in the region of the anti-center. The main thing that has persisted from the thesis research was this so-called cold cloud that has reappeared in recent years. And that was clearly evident in these observations - a little dip there due to absorption by some cold absorbent cloud. And there were a few other things, the distribution - the shape of the line profiles looked distinctly Gaussian to me as opposed to a E^-x type of distribution that [Adriaan] Blaauw had been postulating for other interstellar types of clouds and so on.

Sullivan

I see, on the basis of optical data.

Heeschen

Yeah. And subsequently, I think now the shapes definitely are Gaussian. Well, it was a pretty limited kind of operation because of the sensitivity and resolutions that were available.

Sullivan

You weren't stacking data at all, I suppose, either?

Heeschen

No. The - it was a very slow process. It's a single channel receiver in which you had to scan by frequency tuning over whatever bandwidth you were interested in or wanted to be interested in. And if you're right in the galactic plane and the lines are broad, even in the galactic center they're probably broad, it took awhile to do the scanning. There were a lot of equipment problems. The thing used a, I'm not much of an instrumentalist - but it used a triod oscillator tube that had been developed during the War. In fact, when the project first started it was still classified tool and it became declassified just about the time we needed it - just about the time Ewen needed it for his receiver. And it worked in a cavity that was tuned with a plunger and that was extremely sensitive. If the temperature in the control room changed then the range the control of the plunger would change and we'd have to go back there and blow on it, or put a heater on it or something to try and get the tuning range back. Well, that was about it. I left Harvard in '55 and went back for a year, a year later and worked at the Agassiz project for one year then on the 60 foot and made a series of observations on extragalactic things, most of which, in fact all of which have proven since to be wrong. The classic case perhaps of wrong observations.

Sullivan

Well, you're not the only one.

Heeschen

Oh no. Right. But I detected hydrogen emission in the Coma Cluster and various galaxies, all of which later proved to be incorrect. And that was the end of the Harvard project as far as I was concerned. Of course, it went on and a large number of people got their theses from it.

Sullivan

If I may, what went wrong with the observations, do you think?

Heeschen

With my observations? I don't know. I suppose it had to be something in the equipment that we didn't understand then and still don't understand, because in the case of the Coma Cluster which was to me the biggest mystery - the others I'm not sure of. It might have been a bit of over-interpretation in the case of the others. And they were never followed up as extensively as the Coma Cluster. So I really don't know about them. But in the case of the Coma Cluster I was sure that a line - an apparent line did exist. And in fact, re-observed and then later on when others observed and were unable to repeat my result, went back and re-analyzed all that data in a very laborious way to see if I had misled myself somehow into believing that a line existed when one didn't. For example, I used a variety of different kinds of baselines and actually [?] the areas under the curves. We didn't have any digital data taking then. And the line did exist. So it had to be something in the instrument. I think it was naiveté in regard to instrumental effects that was probably the cause of it.

Sullivan

It was a standard on-off sort of thing you were doing?

Heeschen

It was frequency switching and comparison regions were taken, i.e., the line profiles were obtained in various regions of the sky in and around the Coma Cluster and the line appeared in it but not around it apparently. So it was a screwy thing. I still don't understand it. So I left Harvard and came to NRAO which was just beginning at that time.

Sullivan

That's what year now?

Heeschen

'56, let's see no. I left Harvard in '54 and went to Wesleyan where I taught for a year and went back. So '54 and '55 I was at Wesleyan, '55 and '56 I was back at Harvard for one year and the beginning of '56 I went to work for AUI [Associated Universities, Inc.]. I stayed at Harvard for one year while working for AUI, I worked out of Harvard.

Sullivan

So you were actually being employed by them up there?

Heeschen

I was employed by AUI but was living - still stayed up in Harvard.

Sullivan

To learn the techniques to use at the...

Heeschen

No, there wasn't any place to go. There was no site yet and I spent a lot of time in New York City and other places in developing plans for the Observatory and so on. But my own base remained at Harvard, Massachusetts where we were living.

Sullivan

What were the plans at that time? What was the idea for this national observatory?

Heeschen

The original idea was a 140 foot telescope. That was to be the initial instrument. Way back when, when it first started there was a committee and this all began when I was still a graduate student. I no longer remember who the committee members were on so on and that is a matter of records somewhere, which determined there should be a national observatory - a national radio observatory. They invited AUI to investigate it and decide whether AUI wanted to develop the plans for it. AUI decided that they were willing to and wanted to and went into it. That committee then set the sort of basic scientific goals or instrumental goals which were to be a 140 foot telescope that should be "an off the shelf instrument." Because it wasn't much bigger than 60 which already existed - twice as big.

Sullivan

But ten times the weight.

Heeschen

Well, now wait a minute. This was just a size. The astronomers on the committee - the committee just said the first telescope will be a 140 foot telescope "off the shelf." It hadn't been designed yet. And then with that operating and being the sort of bread and butter instrument for the observatory initially we’ll go on and build an ultimate reflector of much larger size. And, of course, difficulties developed in the design and subsequent construction of the 140 foot telescope which delayed it, made it more costly and the larger one became impractical and was dropped altogether from the plans of the observatory.

Sullivan

So the 140 foot right from the very beginning was the idea. Then when did it become necessary to put in an 85 foot as a stop gap, I guess?

Heeschen

The 140 foot was the one that was originally planned and whether the size was exactly 140 foot or not, I don't remember. I don't know how it became about that it was just 140 feet. But a sort of design competition was organized and various people submitted designs. One was chosen. The one by Ned Ashton and he went ahead and did a detailed design that we bid out. Contracts were let and construction started. At the same time design of buildings and facilities and so on were completed. A rather extensive site search was undertaken with some ground rules imposed by the NSF [National Science Foundation], namely they had to be within 300 miles of Washington. All of that went on, the site was acquired and construction began ultimately on the 140 foot and on the buildings and so on. And we moved down to the site in- I think I moved down there in 1957 so I spent one year at Harvard. In about - must have been about 1958 or so, at that time I was the only astronomer on the staff of the NRAO, in fact the staff was very small just a half a dozen people.

Sullivan

The rest were all construction engineers and electrical engineers?

Heeschen

Well, the rest were contractor people. The observatory staff consisted of me and John Findlay. I was sort of the first professional person employed specifically for the observatory and Findlay was the second. Prior to that time it had been done out of the New York office of AUI - all the planning and design work by contract. And the organizers of that were Lloyd Berkner, who was president of AUI at the time, and Dick Emberson, who was his assistant. And Emberson had a background in physics and was a very good organizer of things and he had a lot of committees that helped him. He did all the detailed organizing and planning through these committees and through contracts. All the construction work was done by contract. When we had a site there were a few others, a bookkeeper, and some grounds personnel, and eventually some technicians and we began to build a receiver and things. But it became clear very quickly that the time scale for the 140 foot was not as short as we would have liked. I think at that point the delivery time was estimated to be '62 or so. And we were faced with the prospect of not having anything. And it seemed to me that it would be desirable to have something going in the way of an observing instrument so that we could begin to accumulate some experience in the nucleus of the staff and so that I wouldn't be totally unproductive for awhile. And we could train telescope operators and just have a working observatory more quickly. And the easiest way to do this seemed to be to get an 85 foot telescope. Which about that time was being designed by the guy from Tuve’s outfit, Howard Tatel, and he was working with Blaw Knox, and the guy at Blaw Knox is Bob Hall. And they came up with that particular design, which I personally believe is one of the best antenna designs of its time. I think it's at least as good as the Caltech design- the two 90 footers. Because it was an antenna with full sky coverage, a surface that's certainly good to 4 cm, and in most of them it's good to 3 cm and used often at 2 cm. And the first few cost $300,000 or $400,000 and even now they're only $500,000 or $600,000 apiece. A real bargain I think in a sense. Anyway, that's how that particular telescope came about - that first 85 foot.

Sullivan

Could you be said to be the head of NRAO at this point?

Heeschen

No. The head of NRAO at this point was Lloyd Berkner who was the president of AUI and acting director of NRAO. And I was the radio astronomer on the staff as sort of a...

Sullivan

You were the ranking man on the spot, so to speak, I guess?

Heeschen

No, not even that. There wasn't actually a ranking man on the spot. I was just out of graduate school remember. I was the ranking radio astronomer on the spot so if they needed radio astronomy advice in a hurry they would turn to me. Findlay was the ranking instrumental man on the spot. He had a background in electronics and physics more than I did - electronics more than I did. And so if they needed technical advice they turned to him, if they needed astronomical advice they turned to me. And we both functioned as sort of staff aides to Emberson, as far as all the construction stuff was concerned- at least in the beginning. And slowly through our own desire to do some observing and to get something going and to establish a pattern of the way the observatory would operate, we developed with the 85 foot telescope a visitor program and the basic pattern by which visitors came to the observatory and used it and so on, got established very early. I think partly as a result of that. And we followed the basic AUI concepts that had been developed at Brookhaven [National Laboratory] and perhaps we modified them a little bit to fit the particular astronomical situation and the fact that we were starting out from scratch. But the basic ideas all sort of grew with the 85 foot telescope at that time. Visitors came and used the telescopes and we got experience in getting receivers, although not very many receivers for them. For example, we learned fairly quickly that we couldn't get good receivers receiving systems from industry and it was better to get components and units and put them together and be our own systems people. And various other concepts developed during that time. The idea not that we would not have groups consisting of combinations of scientists and engineers and technicians each working on some aspect centered around an auxiliary instrument, like they do at some observatories where they've got a 21 cm line group and a continuum group and so on. That would make it difficult for people to switch around from one thing to another and so we chose very early in the game not to develop that way but instead have an electronics group that would service all phases of radio astronomy and a scientific group that would be disembodied partly from the instrumental developments.

Sullivan

It's more by function than by scientific subjects, something like that.

Heeschen

Yeah.

Sullivan

Can you say a little bit about how that came about. It seems sort of peculiar that an optical astronomer...

Heeschen

I can't say because I have no direct knowledge of how it came about. To some extent I think it was partly based on the desire to have a well known person with a good reputation to give some strength to the observatory. The observatory was under fire from various areas as being not desired because - or not needed. It was taking money away from the universities; a continuing story.

Sullivan

But even AUI, of course, is made of universities but they decided that then they had made a mistake or was it other universities?

Heeschen

Well, it was other universities or individuals even at some of the AUI universities. Sure. So I think they wanted a person who was both a good scientist and had a good reputation and would carry some weight of his own influence with other astronomers. And they chose Struve. And he was director until January of 1962 at which point he resigned and AUI searched around for a new director and chose Joe [Joseph L.] Pawsey. In the meantime I was appointed acting director in January '62. And they selected Pawsey and Pawsey accepted the appointment as director. Came over here- actually he came- I'm not sure of the sequence- I think he came over to talk to AUI and look at the observatory and talked to the people there. And then having done that he made his decision and accepted the position to start later. And then he became ill and it shortly became apparent that he wouldn't be able to take the job and he died shortly thereafter. And then in October of that year I was made director.

Sullivan

October of '62?

Heeschen

Yeah.

Sullivan

Let me just ask, what would you say is Struve's main contribution to the way the observatory went or was it sort of a holding action in retrospect?

Heeschen

Well, I don't know. I would just as soon not comment very much about Struve. I think you're going to have trouble in this history in some areas because it's too fresh and a lot of people are still around. And I have got some opinions about things...

Sullivan

OK, I understand. Let me ask about the first users of the Tatel telescope. Was it called that at that time?

Heeschen

I guess so, I don't remember.

Sullivan

I know for instance I've seen that George Field did something on it but here was an example of someone I guess, I don't actually know, doesn't know much about electronics, but so he came right in and used the thing. Were there other people in these early days, of course someone like Frank Drake who knows electronics ... Or what about that Project Ozma, that was sort of an adventurous thing to do at that time? Was that sort of a gamble so to speak that it would reflect favorably...?

Heeschen

I don't think that how it would reflect was much of a factor. I think that Drake wanted to do it. It was a legitimate thing to do. Certainly in my mind it was a legitimate thing to do and in Struve's it was a legitimate thing to do and I think that Struve was aware that it would be subject to a certain amount of criticism and in fact it was. Nevertheless that's not a reason for not doing it. It was certainly not done for the purpose of getting publicity to the NRAO. I think it was done really as an intellectual exercise. I don't think anybody had much hope that it would succeed but it was worth trying and it did focus a certain amount of attention on that problem of legitimate scientific attention. I happen to think it's one of the great things that had been done. I think Drake deserves tremendous credit for stimulating the field which at that time was a very suspect one and now is a big deal and...

Sullivan

Well, it was at zero experimentally wasn't it?

Heeschen

Oh yeah. But it wasn't even a legitimate topic of discussion or speculation at that time. And now, of course, it is. And large numbers of people thought it was a stupid thing to do and that it was done strictly for headlines and that it was a waste of scientific effort and telescope time and so on. And I don't think so at all and as I say I think it is one of the great experiments that's been done in spite of its negative, immediate negative result.

Sullivan

Yeah, I happen to agree with that very much. Although it's puzzling why for a period of say 10 years after that virtually nothing was done. The Russians did a little bit towards the end of that 10 year period, I guess. Why is that?

Heeschen

Well, I don't know.

Sullivan

Especially if you're favorable towards these sorts of things.

Heeschen

I think that nobody else came along first of all who wanted to do it. We were not approached at all during that time at NRAO with requests...

Sullivan

Never a proposal? I see.

Heeschen

To do anything. I think there was a lot of theoretical work that was done. I think that to some extent the negative reaction of some people may have turned off potential observers for a while from it. I think that with so much else happening in radio astronomy people were perhaps also distracted from wanting to that. Telescope time is at a premium, was, and has been. Not many people are willing I think to take their precious telescope time for such a project. And it just wasn't proposed. On the other hand a lot of thought, theoretical work, went into it. I think a certain amount of discouragement developed with regard to the potential of the hydrogen line as a medium for communication too. And that also discouraged observers.

Sullivan

The frequency wasn't obvious, you mean?

Heeschen

That's right. Arguments were presented as to why the hydrogen line wouldn't be an obvious choice. Yeah.

Sullivan

You've mentioned the 140 foot - it didn't get going actually until 1965.

Heeschen

That's right.

Sullivan

And the initial projection, well I guess it was even earlier than '62.

Heeschen

The initial projection was earlier than '62, that's correct. The design, I don't remember now the detailed sequence but I think the initial projection must have been in sort of the late 50s.

Sullivan

About '55 or '56?

Heeschen

No, no. Not '55 or '56.

Sullivan

Oh, in '55...

Heeschen

The design... The first contract for an observatory was I believe in '57 or '58. At that point the design was supposedly finished and a contract had been bid and we were all set to sign a contract. So it was about '57. And presumably the construction time was estimated to be 2 or 3 years, so my guess is '59 or '60 was the projected time for completion.

Sullivan

In '57, I see. That's amazing. Well, what - can you sort of outline what basically went wrong?

Heeschen

I can't really. I think you could go to Dick Emberson who will have the actual facts and the dates and everything else and you can get the factual things from him. Opinion as to what went wrong vary tremendously. In fact what happened was that part way through the design a question came up- sorry, part way through the construction- let me go back. The contract was let on the basis of a design which was in a not complete stage of - it wasn't finished. So construction began at the same time that the design wasn't being completed and, in particular, the design of the bearing and the yoke and so on were not finished. And they went ahead and started construction of the foundation and so on. They started fabrication of the bearing; in fact quite a bit had been fabricated. I believe the polar axis had been fabricated and the yoke arms had been fabricated and the bearing was being fabricated. They had a lot of trouble fabricating the bearing, which is a big spherical bearing, and it was at the time meant to be made out of orange peel segments that were to be welded together. And I think they started to do this and found that they couldn't control the shape of the thing in the welding process. I'm not sure of that. In any event, two things happened. It appeared to be that the design was impractical from a construction point of view of the bearing. And secondly, a question arose as to the adequacy of the steel that had been specified. And it turned out that this steel was subject to something called brittle fracture which is a condition that can exist - can develop in steel particularly if it’s been subjected to welding strains and things like this that aren't thoroughly worked out of it by heat treatment or whatever. And then if it gets very cold the steel can go into a state where a little shock can fracture it. And there was concern that this would happen. This had happened to Liberty ships during the War and it had happened in a few other cases. Concern was raised as to whether or not this was a serious danger in the case of some parts of the 140 foot that had already been fabricated or that were in the process of being fabricated.

Sullivan

You mean mainly the framework for the surface itself?

Heeschen

No, not that. That's aluminum. But the parts that were made of welded steel structures, the floor shaft, the yoke arms, and the bearing. Those three components were made of steel which under certain conditions were possibly subject to brittle fracture. And there was a tremendous controversy as to what the degree of danger was, what could be done about it, and so on. The whole job stopped for a long time. Various committees were formed to investigate the problem and things just dragged on and on and on. And it was then decided that the danger was sufficiently great that they had to throw out those parts and start over. So at that point those components were scrapped and the thing was redesigned. The basic dish structure was never redesigned. That all just sat there during all this period. But at that point it was redesigned. There were other problems. There were contractual problems with the contractor, E. W. Bliss Co., the history of which I'm not totally familiar with and there were problems within the Bliss Co., I believe. They wanted to get out of the antenna business. Some element of the management was unhappy with the job from the very beginning. A lot of these things combined. AUI was having a certain amount of difficulties in managing the job at the time. There was a certain amount of unhappiness within AUI as to the way the job was going. There were differences of opinion within AUI with regard to this brittle fracture question, with regard to the degree of participation by people at NRAO in the job, which was nil. At that point, Findlay and Struve and I and others at NRAO were not involved. A lot of things but the basic problem was this one of brittle fracture. That's the one that ground everything to a halt and a lot of study was made and it was decided that those parts that had been fabricated had to be thrown out and redesigned and rebuilt and that cost time and that cost money. The contract with Bliss was cancelled, so I think the other half of the major problem besides this brittle fracture question was the contractual relationships with Bliss, which proved to be unworkable for whatever reasons. As a result a different company was finally hired, Stone and Webster, to manage the job and they subcontracted the basic parts to various different people, Westinghouse fabricated something, I don't remember now who else. And then the thing went on but this cost a lot of time...

Sullivan

Well, that cost 4 or 5 years basically.

Heeschen

Yeah, and it cost a lot of money. And how much it cost in the way of money is shrouded in mystery now because you don't know really how much the job should have cost in the first place. I think that the original bids were probably grossly underbid and optimistic on the one hand. On the other hand a lot of steel was in fact thrown away and that represented a lot of money. That would be an interesting thing to go dig into, but whether you could actually get it out I just don't know. I don't know where you'd go to do it - someday it would be an interesting thing. Right now there's a lot of - still, I think - a lot of sensitivities because a lot of bitterness was engendered at this time. Emberson left AUI, Berkner left AUI. They were the two people...

Sullivan

Mainly over this?

Heeschen

Yeah, entirely or at least it occurred at exactly the same time. Struve left NRAO. It hasn't been all that long ago I doubt that you'll get a straight story out of it from everybody or from anybody. And in fact, I don't know that anybody can give a whole story. Emberson knows it probably as well as anyone but he was one of the antagonists on the whole thing and so he's got a biased view of it too. And I was sitting on the sidelines - Findlay and I, we were pretty bitter about some aspects of it. In retrospect I think we were bitter in some cases about the wrong things and I just don't know. It was a mess.

Sullivan

Where is Emberson now?

Heeschen

The last I knew he was Executive Secretary or something for the IEEE [Institute of Electrical and Electronics Engineers] and associated with their publications.

Sullivan

And Berkner has died, is that right?

Heeschen

Berkner has died. Berkner was a tremendously driving, vigorous guy. I think a lot of credit for the concept of a national center belongs to him and for getting it started - well I think is a good way - belongs to Berkner.

Sullivan

That's what Merle Tuve told me also.

Heeschen

Oh really. They were not good friends.

Sullivan

Now during these problems of the 140 foot, the 300 foot appeared. Was that once again sort of a - the second dish...

Heeschen

By this time we had a couple more people on the staff. I can't remember who. Again, Findlay and I thought that for the National Radio Astronomy Observatory an 85 foot dish wasn't enough. We were very discouraged with the progress on the 140 foot dish. We wanted something that would give the NRAO a national stature in its own right. And it had to be something cheap. So, we thought of the idea of a transit instrument to try and keep costs down. We went to Bob Hall whom we knew very well from our dealings with him on the 85 foot and we had a lot of respect for him as a designer. He happened to be changing jobs at the time and between jobs he designed the 300 foot telescope. And then we argued for it on the grounds that the Observatory needed something and that the 140 foot was being delayed and that this could be done quickly. And in fact it was done quickly. It was done I think in 18 months from the time of design began to the time the thing was in operation.

Sullivan

And it went quite smoothly, I think?

Heeschen

It all went very smoothly. It was designed to be a cheap instrument with relativity short life. It has proven to be a cheap instrument but the lifetime has been longer than expected. And I think that Findlay deserves a lot of the credit for seeing that it got built. Bob Hall did a beautiful job in designing it. I think the impetus for it came from the radio astronomers on the staff, myself, and Drake, I think. I don't know who else was around at the time.

Sullivan

Mort [Morton S.] Roberts came in '62, I think.

Heeschen

Yeah. The telescope was completed and went into operation in October of '62.

Sullivan

So just as he came here or something like that.

Heeschen

Yeah, just as he came here. Several things happened about that time. Just prior to my becoming Director, there had been a lot of talk about the difficulties of living and working in Green Bank. And one of the first major things that happened after I became Director was the decision was made to move a segment of the Observatory to Charlottesville.

Sullivan

That early, in ‘63?

Heeschen

The decision was made in '63 or '64, I don't remember. But it was very shortly. Because we started very shortly after I became Director we started a rather long study as to pros and cons of moving and if moved what would be involved and who would move and where we ought to move to and so on and so forth. And that was debated in AUI rather exhaustively and then approved and then it took some time to get NSF approval. Then from that point till the time the move was actually made was another year and a half because we had to build a building and everything.

Sullivan

And that took place when?

Heeschen

It took place in '65, I guess.

Sullivan

That's turned out to be, I think, quite successful wouldn't you say?

Heeschen

Yeah, I think so. The separation has its disadvantages but I think the advantages out-weigh the disadvantages. On the other hand I think that NRAO wouldn't have developed as well as I think it has developed if we'd had the separation from the beginning. I have the feeling, I can't prove it, but I have the feeling if we had started out in two locations we wouldn't have established the kind of atmosphere and rapport and operating group that we have in Green Bank now. I would be reluctant to try to develop that from a distance. So in the case of VLA, for example, I want initially everything to be on-site.

Sullivan

You said several things happened about that time. This was one of them...

Heeschen

Yeah. The others were the coming into operation of the 300 foot.

Sullivan

And then the change of directors?

Heeschen

The change of directors, yeah- all in the same couple of year period.

Sullivan

Well, as you've already noted history gets difficult within 10 years but I'm cutting things off at '65 because then it really gets out of hand in size as well as proximity. So I think that covers pretty well. Thank you. So that ends the interview with Dave Heeschen on 28 December, 1973 at NRAO. This is also the end of this tape.