Interview with Frank Drake on 27 April 1979
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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
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.
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Sullivan
Ok, this is talking with Frank Drake on 27 April 1979, part two of an interview which began at Helsinki in August ‘78. And we're going to first of all finish off a couple of things at Harvard. You did with Doc [Harold "Doc" Irving] Ewen, designed an 8,000 megahertz radiometer. Could you tell me about that?
Drake
Yes. Doc Ewen was a very enterprising and creative person who took great pleasure in developing new systems and selling them and making a profit. He succeeded in getting a contract from the Navy to develop a very sensitive radiometer system, which was to be used in radio sextants for navigational ships. His idea was to build a radiometer so sensitive that it could be used with a small dish and yet see enough radio sources that one could actually do regular celestial navigation on a ship. Previous radio sextants had had to use the Sun or the Moon and this had limited their usefulness. To carry out this project, he was actually provided with a very high quality 28 foot antenna which was in a ray dome and was located only about one mile from Route 128 in Boston, in fact, in the midst of an industrial research park of all things and next to an automobile dealer and tractor salesman, and surrounded by the three main television towers of the primary television stations of Boston- All of this within about a half a mile of the telescope.
Sullivan
He's building a sensitive receiver.
Drake
He's building the world's most sensitive receiver. He capitalized on some new traveling wave tube technology, primarily to achieve very high band width, and, in fact, he constructed a 3.75 cm. radiometer with a band width of one gigahertz operating at 8 gigahertz. Now he was at that time, also part of the Harvard radio astronomy group, so we all knew each other, and he twisted my arm and got me to come work for him part time to develop this radio telescope system. At the time it was a great pleasure because the equipment was wonderful and there were all kinds of engineers and technicians available. That is, the funding was very good, and besides Doc paid me what to me was a fantastic salary, at least compared to what I was paid as a graduate student. As I recall, I was paid at such a rate that if I had worked full time I would have been paid $8,000 a year, and at the time, that sounded like an absolute fortune.
Sullivan
Sure.
Drake
And besides which, I had complete control of this radio telescope and very soon he gave me the title of Head of the Astronomical Research Group, which in fact consisted of me. But it was all very impressive. As soon as I started fooling around with this radiometer, I discovered yes, it had a good noise figure and good band width, but the gain was extremely unstable, and so almost unusable. And so we invented a trick, which is essentially identical to the Ryle-Vonberg circuit, of using a Dicke switch and adding noise as necessary so that the receiver sees the same noise temperature no matter which position the switch is in. And in this way, we were able to achieve the full sensitivity that should be provided by the noise figure and band width, and the result was a receiver which was far more sensitive than anything that was in existence.
Sullivan
And did you publish this in Proceedings of the IRE [Institute of Radio Engineers]? In that special issue?
Drake
That's right. The astronomical observations that were done to test this receiver were published in those proceedings.
Sullivan
But Jupiter and Saturn had been detected already by NRL [Naval Research Laboratory]?
Drake
Saturn had not. Jupiter had been.
Sullivan
That's right, it was Venus and Jupiter that they looked at.
Drake
Yes, Saturn was a new detection and we also reported some detections of planetary nebula, but I think they were not correct. I think those were just bad- oh, giving undue significance to the data.
Sullivan
Did you know about the Ryle-Vonberg system or was it independent?
Drake
It was independent but years later I realized it was really the same as the Ryle-Vonberg, but at the time when you're confronted with the problem, the solution is obvious. As far as I know, it was independent.
Sullivan
Yes. That sort of surprises me because the radio astronomy literature and community was not that large at that time, I had the feeling that everyone knew about everything, so to speak, that had taken place.
Drake
I didn't. I don't think Doc Ewen did. Well, soon after that, I finished my degree at Harvard and left and that was the end of that.
Sullivan
You got a job at Green Bank?
Drake
I went to NRAO [the National Radio Astronomy Observatory].
Sullivan
How many people were there when you arrived?
Drake
When I went to NRAO, there was essentially nobody; the only people there when I arrived were Dave [David S.] Heeschen, who had been the first person to go to the Green Bank site. We always were puzzled because everybody that worked at NRAO had an employee number, and Dave Heeschen's employee number was 1. I don't know what I was, about 5 or 6. The only people there were Dave, and John Findlay, one secretary, one technician and me. And it was a very fun time because there were great plans for great things and unlimited funds. We had all the pleasure of picking out the sites for the big telescopes which were going to be built, 140 foot, the 85 foot, putting together an electronics laboratory and that sort of thing.
Sullivan
But there was no telescope when you got there?
Drake
There was no telescope. And when I got there, the only plans were for the construction of the 140 foot telescope; that was the only thing on the menu.
Sullivan
When was that?
Drake
That was 1958, spring of 1958. Now very soon thereafter, it became apparent that the 140 foot was going to be an extremely lengthy project. The decision to build an equatorial mount, an extremely massive equatorial mount in order to provide sufficient rigidity, was leading to a design which was very massive, unique, and full of special features which were going to take a great deal of time to construct. This worried the observatory staff because we saw the possibility that the observatory would have no telescopes for about four years. And so it was decided to attempt to get something sooner and the idea was successfully sold of building an 85 foot telescope as an interim dish to get things going and to have some kind of telescope.
Sullivan
Just an off the shelf sort of thing?
Drake
Off the shelf thing. And in fact, there were two companies building 85 foot telescopes, the D. S. Kennedy Co. and the Blaw Knox Co. that had just built one for University of Michigan. And the funds were provided and after just a little searching around, we decided to buy a Blaw Knox dish. So the Blaw Knox dish was constructed and by the summer of 1959, it only took a year which is pretty amazing, we had an 85 foot dish at Green Bank. Now it turned out that that was all we had...
End of Tape 105A
Sullivan Tape 105B
Sullivan
Frank Drake on 27 April 1979. Until the 300 foot came along when was that - the second dish?
Drake
Yes, the 300 foot was the second dish, and along the way there was a long tail of misfortune that went with the 140 foot dish.
Sullivan
Can you sort of outline this? First of all, I didn't realize that the primary motivation for the equatorial mount you said was rigidity.
Drake
No. The decision to build the 140 foot as an equatorial was made after a lot of soul-searching. There was a choice had to be made between alt-azimuth and equatorial, and after a lot of study, it was decided that the computers at that time were not good enough to control an alt-azimuth mount reliably. Whereas we had had a lot of experience with equatorial mounts and I should say the fact that all the people were from the Harvard group had some influence because both the dishes that had been built at Harvard were equatorial mounts and people felt very comfortable with them and very confident with them. And as a result, there was a bias towards equatorial mounts anyway. But when it was decided that computers were unreliable and possibly would not give sufficient pointing accuracy, they went for an equatorial.
Sullivan
Analog methods such as were used at the Parkes dish? You must have looked into the whole Parkes design?
Drake
No, the Parkes design was never considered. The only thing that was considered were digital computers. No analog design was ever discovered. The equatorial mount, of course, avoids the computer problem, but it has other serious problems such as the direction of the forces on the declination bearings change as the telescope moves. Similarly that the gravitational lobe vectors on the fork which holds the dish changing as the dish and things like that, which make, in fact, an equatorial mount a much more difficult thing to design than an alt-azimuth, which few people realize. The result was that the designs for the 140 foot were extremely massive to get rigidity and they had a very difficult problem with bearings. The whole thing compounded because the more weight you added to give stiffness, the bigger the problem was with bearings and so forth. And it had an oil pad bearing which had never been built before with a spherical bearing surface, 14 feet in diameter. Many things which were very difficult and quite unique. And lots of bad things happened such as, on the day the contract was to be signed at Green Bank for the construction of the 140 foot telescope ,and all the big wheels and such from AUI [Associated Universities, Inc.] and NSF [the National Science Foundation] were there, all rushing to a meeting at Green Bank, the most unlikely and horrible thing in the world happened, that was there was a head-on collision between the Chief Engineer of AUI and the car being driven by the wife of the President of AUI.
Sullivan
Out in West Virginia?
Drake
Yes, right on the road near Green Bank. Terrible head-on collision in which the engineer was killed and the whole meeting had to break up, we had to go out and clean the debris off the road and take the people to the hospital. It was not clear whether the wife of the president of AUI had been killed or not. She was in very bad shape and was rushed off to the hospital and I had to go charging down not knowing whether she was alive or dead. Just awful.
Sullivan
How long did that delay things, then?
Drake
The documents actually got signed that day.
Sullivan
Oh, they did get signed? It was an omen.
Drake
All the parties and ceremonies went by the board. That all happened at an intersection where about five accidents since had happened since.
Sullivan
What were some of the other things?
Drake
Well, then, after the telescope was half constructed, at great expense, it was discovered that the metal that was being used in the polar axis in the fork was subject to brittle fracture- this business that destroyed many ships during World War II, where certain kinds of metal when subjected to temperatures of ten below zero become brittle and lose their strength and shatter like glass. And temperatures do get that low at Green Bank and it was only discovered after all the pieces were all made in fact at Green Bank, that the metal was subject to brittle fracture. And the entire, all the material that had been built for the telescope had to be discarded and we had to start over. They had to stop everything. The original polar axis was buried - you couldn't even scrap the thing.
Sullivan
So it's buried near the present telescope?
Drake
It's buried like a buried monument next to the existing telescope.
Sullivan
Some archeologist will find it.
Drake
Yeah, and wonder what on Earth is this? Another polar axis?
Sullivan
How was that discovered?
Drake
It was discovered by some consulting engineers reviewing the design, and this was years after the design existed, the contracts had been signed, the thing was half built - millions of dollars.
Sullivan
Why were they called in to review the design?
Drake
I'm not sure I don't remember that history. Maybe I knew it once. This raised the price from $4 million to $15 million.
Sullivan
Oh, wow. Because of the delay in time?
Drake
Delay in time, the need to use more expensive steel, the fact that you had to start over.
Sullivan
I see. And how much of a delay in time would you say it ended up being?
Drake
Two or three years.
Sullivan
That was the major thing, really, that...
Drake
The brittle fracture thing was the major delay, yes on the 140 foot.
Sullivan
Any others?
Drake
No other major things, it was major enough, we had to throw away the whole telescope. The rest of it went all right. In 1961, about, we got the idea that we should build a bigger telescope anyway and we came up with the idea of a 300 foot transit instrument. We wanted it to be 300 foot because that was a nice big number and we decided it should be a transit instrument just to save money. And we proposed to NSF to build a 300 foot transit instrument and the NSF response was very interesting and that was that they would give us $1 million to build a 300 foot instrument and not a penny more. It had to be 300 feet, and it was to be $1 million dollars - those were the guidelines and the boundary conditions.
Sullivan
You think the 300 had to do with the Jodrell Bank 250 foot.
Drake
Yes, it had to be bigger than Jodrell Bank and it had to be an impressive number. That's pretty much how the size got set, and then there was $1 million and the result was that the telescope was designed to meet those figures with the peculiar consequence which nobody understands today that the declination coverage is limited. And what happened there was that we designed the telescope at various tower heights and zenith angle swings and got costs or bids and what we discovered was that if the thing was to be able to tilt all the way over to the horizon it would cost more than $1 million, and so we just kept lowering the tower heights until the cost reached $1 million and that is how the declination coverage of the telescope was set.
Sullivan
Right. In fact, you had to dig a hole...
Drake
Yes, actually, we did make a compromise. We found that the way of getting maximum coverage at minimum expense, which involved short towers and digging a hole in the ground so the dish, the south rim of the dish, actually goes into the hole in the ground. And that's why the dish ended up going to minus 20 declination and has the short towers and uses cables and all other kinds of money-saving things.
Sullivan
Right. But in fact of course, it was a fantastic design in terms of output for money.
Drake
Oh, yes. Cost effectiveness was very high and the telescope was a great success.
Sullivan
Almost a, it's a tremendously, to me in contrast to the 140 foot.
Drake
Yes, the 140 foot cost 13 times as much as the 300 foot.
Sullivan
And has produced some interesting science once it got going, but it was... Probably about the same overall, as the 300 foot.
Sullivan
That's a real problem how to measure that. Now I always associate John Findlay with the design of the 300 foot.
Drake
Yes, John Findlay was in charge of the design of the 300 foot and he worked very closely with a fellow in Buffalo named Ed Felton who was a guy who just designed things in his basement. And the design was actually made by Ed Felton, but Findlay and he worked together closely and provided each other with insights and ideas, like the use of cables where members were always going to be on tension and shortening the towers and using the hole in the ground. But it was really the product of those two people.
Sullivan
And it only took a year to build or so?
Drake
Took one year to build.
Sullivan
Okay, we're getting a little bit ahead. Let's go back to when you arrived at Green Bank and you said that Dave [David S.] Heeschen was there and was he the only...
Drake
He was the only other astronomer.
Sullivan
The only scientist or engineer?
Drake
Yes, he was the only one. There was one technician and shortly thereafter we got a visitor from Norway, a short term visitor named Hein Hvatum.
Sullivan
Oh, yes.
Drake
And that was the whole staff for quite a while. After about a year Cam [Campbell M.] Wade showed up, I really don't remember the history.
Sullivan
But Hein stayed on?
Drake
Hein stayed a year and went back to Norway.
Sullivan
For how long?
Drake
He went back for about a year to Norway but he loved Green Bank, he just loved that whole scene, and he got along very well there. So as fast as we could get him back and get a visa, he came back and stayed, of course, as project manager for VLA and all.
Sullivan
I haven't talked to him yet but he's on my list.
Drake
Yes he's got some interesting stories. Anyway, that was the nucleus, and those were the people who built the 85 foot and by the time the 300 foot was built, there were quite a few more people around: Roger Lynds, [Beatty] Lynds, Cam Wade, and I don't remember who all was there.
Sullivan
Was [T. Kochu] Menon there then?
Drake
No.
Sullivan
Mort [Morton S.] Roberts?
Drake
No, Mort Roberts didn't come until around 1964.
Sullivan
Let me just ask, I should have asked back when you were talking about the Doc Ewen 8,000 megahertz receiver and yourself also, in the Stars and Stellar Systems, Vol. 1 you wrote, you talk about it as University of Michigan, University of California, NRAO 8,000 megacycle receiver.
Drake
Yes, that's because after the first one was built and successfully used at Ewen Knight, all those three places bought copies, exact copies that were bought from Ewen Knight.
Sullivan
And I assume he never was able to sell them wholesale to the Navy.
Drake
They were sold and...
Sullivan
Oh, they were?
Drake
Yeah but always in classified applications.
Sullivan
Which are still classified?
Drake
If you turn it off...
Sullivan
Okay, back to Green Bank - so what were you mainly concerned with in the year before the dish was built?
Drake
In the year before we were actually transferring the technology that we'd had before Green Bank. We bought one of Ewen's 8 gigahertz receivers, we bought an inductosyn encoder system for pointing on the 85 foot telescope; we bought a digital computer, a special purpose digital computer to use with the inductosyn encoder so that we could have printouts of positions and the idea was to do very precise things.
Sullivan
That was really state of the art at that time to be building computers for that sort of thing.
Drake
Yeah, it was all tubes, ten thousand tubes.
Sullivan
Who made that?
Drake
A little company in Boston called Control Equipment Corporation. I think soon after it went defunct. It was actually a spin-off from Ewen Knight.
Sullivan
Wasn't there also a general purpose computer at Green Bank?
Drake
Yes, we also introduced the first general purpose computer ever in astronomy in a step by step way. When the 85 foot was built, one of the first things we did was to try to digitize the output, which we did in the simplest possible way, which was to get a digital volt meter that read voltages on mixie tubes and the first such application required the telescope operators to sit there and write down the numbers.
Sullivan
With your digital output - these were then punched up later?
Drake
Yes, or whatever. Actually usually analyzed just by reading them off by eye. And then soon after that we got a printer, which we could connect to this thing that would print the output, so you actually got a printed version which was on a tape like a cash register in a grocery store. And the first visitor at Green Bank ever to use that system was Gart Westerhout and he quickly automated it by tying a string to the read button so you could sit in a chair and he would watch the mixie tubes and when the thing was reading something reasonable, he'd pull on the string like he was flushing the toilet, and the printer would print. That was the first digital system in astronomy, in radio astronomy, I guess in all of astronomy. And soon after that we decided we should get a real computer and so we got what was then a small scientifically oriented computer, which was an IBM 610, I think it was called.
Sullivan
610, yes.
Drake
An early model that was all relays and tubes and you programmed it by plugging wires into the board and you couldn't have more than about 100 program steps and otherwise the only input/ output was a bunch of paper tape, and we used that thing for about a year, but that turned out to be a real revelation. It really got digital computers started. That was the first one as far as I know, in all of astronomy.
Sullivan
It was sort of like what we would call now a simple $20 calculator in terms of what it could do.
Drake
It wasn't even as good as the present hand held calculators.
Sullivan
Well maybe the very simplest ones.
Drake
Yes, but it was slower.
Sullivan
It didn't have trig functions.
Drake
It had no built-in functions at all, and it had I think maybe 300 memory steps or program steps maximum. So when we saw how really what a big help even that thing was, we quickly got another computer and I can't even remember what the name of that one was. It was made by a small computer company which has now gone defunct. It was much more powerful but you had to program it in machine language and so we all had to learn machine language, which was both a challenge, and in fact, programs were a great step ahead in their power for what we had before.
Sullivan
Do you think this automation was important in terms of the success at Green Bank?
Drake
Yes, I think it was...
Sullivan
Or was it just a convenience?
Drake
Well, it played several roles. It was a convenience, it really did expedite things, but also it created excitement at the Observatory by trying out all these new things. It was a source of good morale and motivation to have all these wonderful toys. We quickly we had that other computer, I can't even remember it's name, for only six months or so because we moved on to a super new model of IBM's which was the 1620.
Sullivan
That used cards, didn't it?
Drake
Yeah, that one used cards.
Sullivan
I actually used that in 1965 at NRL [Naval Research Laboratory] the first summer I was there. You had to read them and compile separately.
Drake
Yes, that was really the first of the modern style.
Sullivan
Used Fortran.
Drake
Yes, that one used Fortran - that was the first one we had that used Fortran.
Sullivan
And when was that?
Drake
That came in 1962.
Sullivan
Okay. Let's go back to the first observations you did on the 85 foot. What did you think were the things to do with this dish?
Drake
Well, the first things of course we did was calibrate it, and then to me one of the first things one should look at was the galactic center. We had what was then a much improved beam width over anything that existed. So we looked at the galactic center and discovered it was resolved in a whole bunch of sources. Things that are now known as Sagittarius A, and Sagittarius B...
Sullivan
You talked about four sources here in one paper. Yes, the four primary sources, Sky & Telescope, this is a AAS [American Astronomical Society] talk.
Drake
That's right. Those are the sources that nowadays are known as Sagittarius A, Sagittarius B, and the others...
Sullivan
[AUS?]- Oh, no you didn't have those...
Drake
A was not resolved and B was not resolved and then there were the two outlying sources; I don't even know have names.
Sullivan
I don't think they have specific names.
Drake
Looking up here at the map - the four of them are there.
Sullivan
This is a 2 cm map?
Drake
That’s a 140 foot map, later. But the four from the 85 are the four you see up there - one's A, one's B and the other two...
Sullivan
I don't think they have specific names, no.
Drake
I remember the interesting thing was that Struve had taken over as director by then.
Sullivan
What was the director - Berkner was director then?
Drake
Berkner was there until Struve came.
Sullivan
Berkner had never done any astronomy.
Drake
No, he was an ionospheric guy originally. It was his wife that was in the auto accident. And he never participated in the science; he was just did the director's chores while we found a proper director. The history there, of course, is that they did recruit Joe [Joseph L.] Pawsey which was a very good step and Joe came to Green Bank and came down with a brain tumor while he was there which was a whole other story.
Sullivan
Well, I have heard it from Australian's point of view, but that would have indeed, changed the history rather if he had become director.
Drake
Yes. He came to Green Bank and was full of good ideas, very enthusiastic . He came to spend a month or so and was going to go back to Australia and pack up and come back to take the job. And he came for about a month and full of good ideas and was very stimulating to the staff - he knew a lot more than the rest of us about things, particularly about interferometers and stuff like that because he really invented aperture synthesis if you check the literature. He was the first to recognize the significance of the Fourier transform as a way of describing an image. And I remember one day I went into talk to him about something scientific- I don't remember what it was now- and he said, "You know, Frank, something's funny." "What?" "I'm asymmetrical today. One leg works different from the other." And actually it was within just a few days that it got bad, and he went to, he was told he should go to a hospital and have a check. And they diagnosed it as multiple sclerosis. Actually after a few weeks he got better and came back to Green Bank and completed his visit. But then he got really bad; he was almost paralyzed on one side so they shipped him off to Boston. Operated on him and all of that but actually they never told him that he had terminal cancer, that there was no hope. Right to the end he thought he was going to recover and come to be director of Green Bank. Nobody would tell him - his wife didn’t want him told, and the result was that we couldn't recruit for another director. So he actually went back to Australia and as far as he was concerned when he got well he was going to come to Green Bank. Actually he lingered for a year.
Sullivan
So that delayed things?
Drake
That delayed things and AUI brought in a guy that was a trustee to look into things - one of them was Struve. After a lot of hemming and hawing, they decided they should make Struve the director. He was very reluctant to take the job because he thought he wasn't really qualified, but he thought it was his duty as an astronomer. So he came and became director of Green Bank. He was always uncomfortable.
Sullivan
This is such an opposite approach from Pawsey who knew every bit about antennas and interferometry and so forth to someone who knew the astronomy but nothing about the technique.
Drake
He was an eminent astronomer; he had experience in running an observatory, but he knew nothing of the techniques or much about the science at all. I remember one thing he said when he came was that he thought radio astronomy had no future, that it would all be done and finished in a few years unless we found variable radio sources.
Sullivan
And then you monitor forever.
Drake
Yes. Variable radio sources then we could monitor forever. I remember that was his assessment of the situation in radio astronomy. The other thing I remember was that when we resolved the galactic center, I took the data in and showed it to him. He said, "Well that one result justifies the whole cost of this place." He was thrilled. I guess he never imagined you would see the galactic center in detail. As an optical astronomer, it was this thing covered by dust and here was actually a detailed picture of it.
Sullivan
I guess it was understood that he was only going to be around for two or three years before he would retire.
Drake
Yes.
Sullivan
So he was a sort of interim director.
Drake
It was an interim thing till he retired, and when he retired, Dave became the director.
Sullivan
Well, anyway, back to what you wanted to do with the 85 foot, so you measured the galactic center.
Drake
Then I was interested in planets.
Sullivan
Which was the highest frequency it had been done at, before it had been recognized by the Australians that...
Drake
Yes, but had not been resolved. It had been seen at many frequencies but not at this beam with or this high frequency. So then I was interested in planets, particularly because Connie [Cornell H.] Mayer was getting his weird results on Venus of the high temperature. So we did a big, long program on Venus, all written up, where we got the phase function and established that the temperature was high. And then we also heard that Russell Sloanaker at NRL was looking at Jupiter and seeing a high temperature there. That intrigued us, so we turned the 85 foot on that and that was Hein Hvatum.
Sullivan
This was at 10, 20 cm.
Drake
Sloanaker was seeing 600° at 10 cm. which was the same as Venus same temperature and same wave length, which was kind of amazing. So we thought well, we'll see if it is the Venus situation all over again. So we looked at 1420 because we had that frequency, which was Hein Hvatum, and we got a much higher temperature, 3,000° and then intrigued by that, we instrumented the thing at 440 megahertz and looked there, and we got 13,000°. So we had this non-thermal spectrum, which was all very exciting, so we published it and suggested that Jupiter could have radiation belts. A little aside to that story, not a very nice one, is that just as we were doing that we had the high temperatures, John Bolton was at Green Bank and he was wondering what was going on so we told him we've got this really exciting thing. I showed him the data on Jupiter, "Look, Jupiter has this fantastically high flux density and it looks like a non-thermal spectrum". He said, "Oh oh." and he left. And the next thing we knew - it was just at the time we published, suddenly a paper came out of Cal Tech which-was [Venkataraman] Radhakrishnan's and Roberts’, I guess...
Sullivan
That's right.
Drake
Reporting the discovery of this high flux from Jupiter. I thought that was very funny, and later I asked Radhakrishnan, "What caused you to do that?" And he said, "Well, John Bolton came back from that trip he made to the East and he said, "You might just go out and take a look at Jupiter; you might find something very interesting." So he stole that result in a very funny way; that was a real shocker to me. You hear of those things happening.
Sullivan
And they did, in fact get into print before you did?
Drake
I think they did.
Sullivan
Now, were you having trouble getting these results accepted by the planetary astronomers?
Drake
No.
Sullivan
I know that with Venus, I talked with Connie Mayer, that they thought there must be something wrong that the radio people didn't know what they were - how to interpret their own data.
Drake
Well, it certainly never bothered us - we just published.
Sullivan
You don't remember any conflicts?
Drake
No, I don't remember anyone ever getting upset - no angry letters or anything.
Sullivan
And what made you think of the radiation belts - I suppose it was the Jupiter activity, the decametric activity which was...
Drake
No, it was non-thermal spectrum. We knew about the synchrotron radiation and the fact that the terrestrial Van Allen belts, which were recently discovered- it was big news.
Sullivan
Ah, yes that's right. That would be the influencing but now the polarization was picked by Radhakrishnan, was that a bit later?
Drake
No, that was...
Sullivan
Was that that same first paper?
Drake
Same paper was the polarization and the fact that the source was larger than...
Sullivan
You hadn't checked for the polarization yourself?
Drake
No, we had not thought to do that and we had no way of measuring the size, all we could do was the spectrum.
Sullivan
They were using the interferometer at Owens Valley.
Drake
Yes.
Sullivan
Okay. So that was the planetary work. Now before we get to Ozma was there any other products on the 85 foot that we...
Drake
Not that I know of.
Sullivan
I don't see any other.
Drake
I did just planetary and galactic center on the 85 foot.
Sullivan
So, that brings us to Project Ozma. Can you tell me, first of all, have you always had an interest in the idea of communicating with another civilization? I mean like back to high school or something?
Drake
That interest goes way back. Not that it was a burning interest; it was a casual one like almost anybody. I wasn't a great science fiction buff or anything like that. But all I know is that when we finally started building the 85 foot telescope, it just occurred to me to sit down one day and calculate how far away you could detect a reasonable signal - from what distance. And it came out to be light years.
Sullivan
You had an interest before, but you'd never done any back-of-the-envelope calculations or anything?
Drake
No, no. Nothing like that - nothing until that time, when there was an 85 foot on the horizon. So I made the calculation and discovered that if we went to a fairly narrow band, we could reach ten light years or so and detect signals like those of the strongest terrestrial signals. And on the day we went to lunch with Berkner- it was a custom at Green Bank then that everyone to eat together - there was no cafeteria or anything, we used to go to a diner at a place halfway to Bartow, a little hamlet you go through on Route 28. We went there for lunch one day - there was Dave and John Findlay and Berkner and I just mentioned that I'd done this calculation, "Isn't that interesting?" And Berkner said "Well, you know, maybe you ought to do something with it." And I said, "I'd like to try it." He said, "All we had to do is build a narrow band system and if we're clever about it, we could use it to measure Zeeman effect." So okay, that's how the whole thing got started.
Sullivan
And for a transmitter power, you were assuming...
Drake
I don't remember now, but it was whatever existed in those days.
Sullivan
Yes. And then you've actually told this story in some detail in that Cosmic Search article. And then the paper by Cocconi and Morrison while...
Drake
Oh, that was long after, because we started, there was snow on the ground that's what I remember that day, so it had to be in the spring of 1959. We decided we were going to do it and we proceeded very slowly, it was done on the side and, in fact, a lot of the equipment construction was built by a visitor who came from England that summer, which was putting together the equipment. So that summer we were building it; Struve had taken over then.
Sullivan
Do you remember his name?
Drake
Ross Meadows - he was a visitor from Slough in England. He spent the summer on sort of a sabbatical, building this thing. We recognized right away that if anyone found out we were doing this, we would be hounded by news people, so we had a policy of not saying a word about it. Then in late, I guess, Morrison and Cocconi was September or October that year. Anyway, six months or so after we were working on it, out came the Morrison- Cocconi paper and a lot of publicity. What I remember also is that's also in Cosmic Search. Struve got really upset. It turned out that he, from his history, was very conscious of the importance of publicity. And recognition and getting credit and stuff - that was a big thing to him. He got very upset because he thought Morrison- Cocconi were going to get credit for this whole idea when actually it had been born six months or so earlier independently. So he wanted to make a lot of publicity, and I was against it, but what he did do was that he was scheduled to give a series of important lectures at MIT, and he went and gave a whole lecture on the subject and announced the Project Ozma - let the cat out of the bag, and it was all just to get it on the record, so that Morrison- Cocconi wouldn’t get all the glory.
Sullivan
Steal some of their thunder.
Drake
Yes, he did it on purpose.
Sullivan
This meant, undoubtedly, that people descended on Green Bank to...
Drake
Yes, that's right. The rest of the story is all in Cosmic Search, reporters and all that stuff.
Sullivan
What I'm curious about. I mean, there are many coincidences in time in science, where the time seems to be right for something. Is that the only way that you can describe the fact that both you and Morrison- Cocconi were you going to go at 21 cm?
Drake
Yes, we were doing 21 cm right from the start.
Sullivan
On the principle that it would be a common frequency?
Drake
No, that was our basis. That was Morrison/Cocconi idea. We did it because the equipment could be used for Zeeman effect.
Sullivan
Okay.
Drake
And we could be sure we weren't wasting anything.
Sullivan
So it just happened that your plans fit very neatly into theirs.
Drake
Yes, but we never justified it on the basis that this was a magic frequency.
Sullivan
I see. So you were really shooting blind, in terms of frequency?
Drake
Well, we had picked the frequency which we had receivers for and where the equipment would be useful for other things.
Sullivan
Right.
Drake
At that time, that was only 21 cm.
Sullivan
Do you see any other reason for this coincidence in time?
Drake
No, it was really a coincidence.
Sullivan
Other than the technology was getting such that you had sensitive receivers and big antennas.
Drake
Yes. Dave could make the Sun calculations. That was for the first time we had receivers and antennas- they'd taken a big jump. Up until then we didn't have much more than a 10 foot antenna. Also, parametric amplifiers and masers had just been invented, so the noise figures had suddenly gotten better by a factor of 10. Overall, you jumped about a factor of 100 in sensitivity in just a few years. If they hadn't made the calculations, a lot of people were going to make that calculation in that time.
Sullivan
Still, it's a bit surprising to me that someone, granted it would have taken the exceptional person but there are some around, in 1950 could have seen ahead that it was only going to be a matter of time and one could do this and just publish.
Drake
Yes, actually it's probably in the literature somewhere.
Sullivan
Weil, I haven't seen it explicitly in any form. [Nikola] Tesla talked about communicating with Mars. I've been looking at of his old papers in the last couple of weeks.
Drake
No quantitative stuff.
Sullivan
But it could have been done. So, the program went ahead and I'm curious that you were able to get so much time to do this. You spent a couple of months of actual observing, and of course, quite a bit of time...
Drake
Well, there was not much proposal pressure.
Sullivan
From outsiders.
Drake
From outsiders, there were only a few on the staff. There were just not many radio astronomers then. So it was possible to...
Sullivan
And the other thing that makes me surprised about the time is, of course, there is much more proposal pressure now, but also the idea of SETI is a much more familiar one now. At that time, it must have really been looked upon as a strange way to be spending telescope time.
Drake
It was, but people hardly knew it was happening, except for at the observatory.
Sullivan
Nevertheless, after it had happened, what I'm trying to get at is can you give me some feeling for the attitude of the average radio astronomer that you would run into that either brought this subject up or had found out about it some way?
Drake
Well, to them it wasn't a lot of time, it was a matter of- in those days everything went more slowly - people integrated a long time.
Sullivan
Yes, that's true.
Drake
A few hundred hours of telescope time is nothing, and so it was considered really insignificant.
Sullivan
It was sort of like the SETI ones now, a minor part of the overall effort.
Drake
Yes. Relation to the rest of what was going on, it was about the size of the SETI things now, so nobody considered it something to...
Sullivan
That's interesting but what about the attitude nevertheless- would it be different? I mean, there are a lot of people now who look at it as a big waste of time.
Drake
I don't know.
Sullivan
Was it just so new that...
Drake
I never really got a good feel for what people thought about it. Everybody knew it was a very long shot, but then when we looked at a couple of stars and very few frequencies. Everybody knew it would only work if intelligent life was very active for reasons that we couldn't even dream of. So nobody really expected success.
Sullivan
But then you were interested enough, of course, to pull together this conference at Green Bank, which was in 1960?
Drake
No, that was after Ozma, 1961, I think.
Sullivan
But it was clear that you wanted to keep on with this and go on to better methods and bigger telescopes, et cetera. Can you sort of identify what it was that gave you this zeal at that time?
Drake
Interesting subject.
Sullivan
The more you got into it...
Drake
It's the Holy Grail, and it still is.
Sullivan
The more it began to fascinate you. But you didn't have that, though, before you made this back-of-the-envelope calculation.
Drake
No, it was really that. It showed it made sense. With the quantitative possibility, that gave it life.
Sullivan
So it wasn't a matter of something you'd always been interested in when you were in the Navy and so forth?
Drake
No. I don't think I ever thought of it.
Sullivan
Okay. So you left Green Bank in...
Drake
In 1963, I went to JPL [Jet Propulsion Laboratory].
Sullivan
Where there was no radio astronomy group per se, they were doing space science.
Drake
I was with the planetary sciences group, which did radio astronomy on other things. At the time that switch seemed like a great step forward. I think Green Banks, six years, it was getting kind of dull. Here was JPLwith its space craft and thousands of people and fancy gadgets, so I went to JPL and it turned out to be a dreadful place where all you did everyday was re-juggle budgets. And the very oppressive thing was you weren't allowed academic freedom. You couldn't pursue what was interesting, you had to pursue certain subjects which were sort of laid down. Which I'd never experienced before and never realized it was a very de-motivating situation. So I got out of there as quickly as I could. Within a few months, I was already searching for jobs elsewhere.
Sullivan
And then you came here to Cornell.
Drake
There was one at Cornell, the Cornell people had made a decision to build an Astronomy Department and were building a receiver. I visited Arecibo.
Sullivan
In ending, can you just tell me what the situation was that you found when you came, relative to Arecibo?
Drake
When I came here...
Sullivan
When did you come?
Drake
I came here in the fall of 1964. Arecibo was built and barely operating, one frequency- 430. There were three astronomers here besides Tommy [Thomas] Gold and that was Ian [?], Marshall Cohen, and me. Marshall Cohen and I were sort of the radio astronomers for Arecibo. There were a couple on this thing called- the thing was primarily ionospheric, and it also was operating very badly. It was the feed, 430 feed was a disaster - which it remained until ‘69.
Sullivan
Right. I've gotten Gold's version of that.
Drake
So there were a few people; there was a telescope and it wasn't working well.
Sullivan
Was that the only major thing that was wrong with the whole development of Arecibo?
Drake
Yes. The only thing where things really went awry was in the feed.
Sullivan
That's sort of amazing because I'm sure that everyone was concentrating their efforts on the tremendous mechanical engineering problems and then it turned out to be electrical.
Drake
Yes. It was an electro-magnetic problem.
Sullivan
I didn't ask you, one more final question - you wrote this article about radiometers in the late 1950s, and that gives us a good idea of the state of the art as you saw it at that time. I'd be interested in your point of view from now as seen in the late ‘50s, what were the limitations at that time - was it really in the radiometers?
Drake
In the late fifties, the limitations to everything that everybody did was in the radiometers and it was always a problem of gain stability. The common limitation and concern of everybody was the zero stability, what’s the zero stability. And every observatory had all the engineers trying all kinds of tricks and gimmicks to stabilize the radiometers. That was the name of the game. Nowadays that's all solved and nobody talks about it anymore. And the radiometer has faded into the background as the center of attention of what people do. Nowadays it’s all the software and the hardware - computer programs. But in those days, it was a whole different story - it was all the instability of the radiometer.
Sullivan
And what, essentially, enabled that situation to be repaired?
Drake
Just the development of better electronic components and circuits. Many different ways - the electronics have just improved.
Sullivan
And the paramp improved.
Drake
The paramp improved - the first sensitivity was terribly unstable when it was new. The masers are good, nowadays the astronomer, a lot young astronomers don't even know what that black box is all about, and don't worry about it because it works so well.
Sullivan
Right. That ends the interview with Frank Drake on 27 April 1979 and this is the end of the tape.