Harold Larson, on the airborne spectroscopy program

I’d never been in Arizona, so I just got off a plane and here I was. Everything was new, shocking. I didn’t know what was happening because I took this job by mail from France. I like to say I was a mail-order professor. I hadn’t made any visits; I had no idea what I was getting into. I had never met Kuiper; all I had was two letters from him.

So that was the way I arrived, and it took a while to settle in and figure out what my role would be. Kuiper of course was pioneering the use of aircraft. He wanted to use this particular type of spectrometer that Harold Johnson was developing, perhaps more for use on the ground, but Kuiper saw a role for it in an airplane.

So there was an emerging technology, all kinds of changes, all kinds of potential—discovery potential, you might say—and Kuiper had the sense to know that he could be one of the first people using it.

That’s why he hired me through the mail. I was working in France on a post-doc with a team of people who had also been pioneering the use of this kind of instrumentation, not for aircraft, but for ground-based telescopes. I had become familiar with the optics, the technique, the computer programs. My job when I came here was basically to step in and pick up the pieces, and continue developing this program of airborne spectroscopy.

So as soon as I got here I got engrossed in what he was doing on the CV-990; that was the four-engine passenger jet that NASA had acquired. Nothing worked. Nothing even came close to working. But we acquired experience with trying to make things work in what really is a very hostile environment.

Then something very tragic happened. The plane we were using crashed. It crashed out on Moffett field, in the Bay area, and that put an end to what Kuiper was trying to do. But by that time he had demonstrated well enough the potential that NASA replaced that plane with a bigger plane, the C-141, which is a military aircraft, and which eventually had a 36-inch diameter telescope. That isn’t a very big telescope by today’s standards, but it’s a very big telescope because it has to look through a hole in a plane that wasn’t designed for it.

That facility came on-stream after Kuiper died. He saw the plane, but he never flew on it. He walked through it, but he never flew on it. It was eventually dedicated to him. After he died it was dedicated to him because of his pioneering work directing NASA’s attention to doing astronomy this way.

The C-141 became operational in ’74. I was one of the first groups to fly on it, and one of the last. For me it was about a 25-year involvement. It was a plane that had no insulation, so it was noisy, it was cold, it had no windows, and you just sat their for 72 hours being bored because nothing was happening, or when you were observing, you were watching your instrumentation, you were worried about things going wrong every second, and while computers were running everything you were always ready to press buttons and take control if something happened.

Observing isn’t pleasant. It is hard work, it’s tiring, and 80 to 90 percent of what you do is never useful for anything. It’s a very low efficiency operation. But then you get a discovery. And then you forget all the bad moments because suddenly something is important. We had enough discoveries to make the whole effort worthwhile.

George Rieke, on inventing infrared astronomy

Gerard [Kuiper] had a sort of strange attitude for something called the Lunar and Planetary Laboratory, that is, he brought in people that did, I would say, slightly offbeat but very technically advanced kinds of astronomy. [Harold] Johnson left before I joined the lab, but I gather that he used to joke that he was in the stellar division of the Lunar and Planetary Laboratory, which was sort of true.

Because Gerard had this interest in infrared, one of the offbeat areas that flourished was infrared. So he brought Harold in, and Harold had been befriended by a young physicist named Frank Low while he was in Texas. Harold quickly became Frank’s mentor in getting into infrared astronomy. So then you had three major figures in infrared astronomy—not that there was a field of infrared astronomy, but they became major figures as time went on and people realized how much they developed it.

Harold was the premier person in photometry. He knew how to take the data so you could inter-compare stars and study them and actually make field advances in science. He really started with the first photometry measurements in 1961 or 1962, and in 1966 he published a review article with all the infrared photometry results that he had done. That review article is still cited. It’s incredible that in four years he went from a clean sheet of paper to a mature area of astronomy.

Harold had ideas of how to build [photometric] telescopes that would be cheap, they didn’t have very good optics, and they could be moved quickly around the sky, which meant you’d unclamp the telescope and move it manually, just hang on the telescope and move it. The 28-inch was the first one. Harold and Frank then developed and carried out all kinds of pioneering infrared astronomy using the 28-inch. Harold then got a 60-inch telescope built, which followed the same premise of the photometric telescope. It was getting about as big as you could move with my hand, but that’s how it worked. We shifted a lot of these efforts to the 60-inch.

Gerard had his own 61-inch, and interestingly, I found a progress report that Gerard wrote on the 61-inch about a month after it was first being used. In the progress report it said that Frank had discovered the internal energy of Jupiter—which was one of the major discoveries of infrared astronomy—within that month. It tells you something really interesting, which was that infrared astronomy was super-ready to have discoveries come out. There were things that were well within in reach of the detectors and capabilities that people had then, just sitting there, super-saturated with discoveries ready to be made.

For quite a while the 61-inch in the infrared—at least the thermal infrared, which means the wavelengths beyond two microns—was by far the most sensitive telescope in the world. We used to make observations and send them over to Caltech where there was another infrared group, and they would actually not be able to confirm the observations, but they turned out to be right. They had the 200-inch, but the fact that we had optimized the 61-inch so carefully for this application gave us a big advantage.

There were really three centers of ground-based infrared that sprang up. There’s this one, and shortly after Caltech under Gary Neugebauer, and not too long after that Ed Ney at the University of Minnesota. I think the fact that there were three was actually important. You wouldn’t tell the deep secrets of how you did something, but you would show enough that people could benefit from what you’d done. In some ways the rivalry was fiercer than at present, but in other ways it was much more gentlemanly—the way you imagine science should be done, where people pass things around and say, “What do you think?” I think that sense of community was really important to getting the field started.

George Coyne, on the balloon polarimetry program

My original work with Tom Gehrels was great. We had a nice team there [including Krzysztof Serkowski, Martin Tomasko, and graduate student Ben Zellner]. We would fly balloons, because these were early days of the space program, so you couldn’t send a rocket off into space at that time. But you could send up balloons, which would get up above a lot of the Earth’s atmosphere, and do research in infrared from balloons.

There was an agency of the federal government called the National Center for Atmospheric Research, NCAR. They had a site in Northern Arizona and a site in Palestine, Texas for launching these things. One of the exciting things we’d do is once or twice a year we’d go to these sites and we’d fly these balloons. They were very early days so even methods of collecting your data were being developed.

Then the polarization went into all kinds of new and exciting areas. We first discovered that some stars give off polarized light. That’s very important for knowing the kind of structure of the atmosphere of the star. Then we found that some galaxies give off polarized light, because they have very energetic sources at their center and that light is scattered as it comes out from the galaxy. So that whole research in polarimetry began to broaden from planetary into all kinds of other objects. They were the early days of my research.

Don McCarthy, on observing with Frank Low

Frank Low was always fun on observing runs, because he has this tremendous insight into what problems were. We were just exploring. We measured some of the first sizes of astronomical objects. That became my thesis, and it led to me doing the same kind of work at the Multiple Mirror Telescope [MMT], which back then was six separate 72-inch telescopes.

No one had really ever envisioned that you could adjust the way light bounces to each telescope so that all those distances were equal, so that instead of the telescope performing as six separate 72-inch mirrors, it performed as one 6.5-meter telescope that you just used six parts of. We learned how to make those adjustments. That was the start of a different kind of interferometry, which you have today at many different facilities where the telescopes are separate and you bring the light together.

One day we were driving up the MMT road [on Mt. Hopkins] for one of these observing runs, and this was before the MMT was dedicated. They had what were called Friday Night Specials: They would have Friday nights devoted to scientists who would come up there and try to do experiments under non-ideal conditions. We were doing one. So Frank’s driving us up the mountain, which is a very scary road and was scarier then before they paved a lot of it.

We go around a corner—it’s a one-lane road—and this big Greyhound bus comes down suddenly from the other side. Frank’s reactions were very quick: He took us right into the side of the mountain; not on the outside of the mountain but the inside.

The Greyhound bus—there was no way that momentum was going to stop. They were practicing for the dedication of the mountain the following week or two. Those Greyhound buses were out there without anyone’s knowledge, just learning the road.

The interferometry actually began on the 21-inch telescope here right behind us. Frank gave instructions that if I ever got it working to phone him no matter what time it was. So I remember 3am phoning him when we had the first interferometer working. That led to the MMT eventually, and to the design of the Large Binocular Telescope because it’s two separate mirrors whose light you want to combine. So the legacy of that was pretty huge, and we had some fun times doing it.

There aren’t many times when you have a place or a group of people who start something completely new. It’s getter harder and harder to do, I think. What Frank Low did with infrared astronomy is simply not common or maybe not possible today: To make a new kind of detector or instrument here on your desk, take it to a mountain, put it on a telescope and discover that Jupiter has its own energy source. That’s just not common. To explore a whole new realm of the electromagnetic spectrum was really odd. Or to start a whole new way of exploring, namely the space program, which LPL figured in so prominently, is really amazing. It’s not like it was in the LPL days of infrared astronomy, where you put together a detector and haul it up a mountain and you’re doing an observation and discovering something all in the same day.

Steve Larson, on Kuiper’s search for telescope sites

I grew up under Kuiper’s style. Most of the great investigators and scientists at the time of course were very proud of their work and worked hard to maintain their position in the field and all that. But Kuiper was of such stature, all the people in the lab basically went along with what he dictated.

He was fully aware of the fact that in the post-Apollo era of NASA it might be difficult to get funding for the kind of research that was going on at the time. So he started looking at other sources. He was spending a fair amount of time with a colleague in Mexico, Guillermo Haro, who was interested in striking up collaboration with American observatories. They had some money at the time to build an observatory, so he spent time site testing for new observatories. He used to fly down to places like Southern Baja with small telescopes, to see what the seeing was like.

One of Kuiper’s true legacies was identification and establishment of what are considered now great observatories. He was the primary ruler in establishing Mauna Kea observatory, and in fact the first telescope set up there to do site testing was an LPL telescope, a little 12-inch telescope that was used to determine how good the seeing was. An observer went there for several months out of the year. That kicked things off at what many people now consider now the premier ground-based site.

Funny as things went, that was sitting on a cinder cone that is now considered sacred, and there is no telescope there. It’s the one peak that has no telescope. All the telescopes are on other ones nearby. He was getting ready to put a proposal to NSF to build telescopes up there with Harvard, and the Hawaiian politicians got involved, saying Hawaii should be involved, so they ended up going another route to develop the telescopes. But he also, in conjunction with the Mexicans, helped established the San Pedro Mártir Observatory in Northern Baja. In fact the crew that attended the telescopes here took a month off and went down there and actually plowed the road to the top. That turned out to be a very good site.

He was always looking for high sites. He had looked at the San Francisco peak, Agassiz Peak as a high altitude site. The higher you go, of course, the less water vapor you have to look out through, which absorb infrared radiation, so you want to be in tall mountains. His search for the ideal infrared site was one of the reasons they named the Kuiper Airborne Observatory aircraft, the C-141, which was used with a 36-inch telescope for many years.

Of course Kuiper had worked hard to establish the telescopes on the Catalinas, and had in fact, when the Air Force vacated their summit with the radar site, wrote a proposal to use that for a site, which is still used today.

William Hartmann, on the Mauna Kea telescope site

In the summer of ’64, Kuiper was the first person to get the idea that there should be observatories on Mauna Kea, or at least that Mauna Kea might be a fantastically good site for observatories. This is funny because what they were looking for was lack of water vapor. Water vapor absorbs the infrared light coming in through the atmosphere, so you want to get up above it. You’d think the worst place would be out in the middle of the Pacific Ocean. But Mauna Kea is so big—14,000 feet—it sticks up above most of it. Kuiper hit on this idea of going up there and seeing if there could be an observatory there.

Kuiper had a history of hiring interesting, off-beat people, like Ewen Whitaker. He had been the head of the lunar section of the British Astronomical Association, which is basically an amateur association. Another example was Alika Herring, a guy who built very high quality amateur-sized telescopes, and Kuiper hired him to come in and take his homemade telescope down to Hawaii and do site testing down there.

In the spring of 1964, Alika had been down there for a couple of months, I guess, living up at the 10,000 foot level in little stone cabins that were sort of Ranger cabins and then driving up to the 14,000 foot level at night. Okay, time for Alika to have a vacation. Kuiper sends young Bill, me, down to Hawaii.

That was the first time I had ever been to Hawaii. I just completely fell in love with the Big Island; it’s such a wonderful place to be. Kuiper said, “Now, you take some days off and go down to see the volcano part, because this is part of your training, and see craters and lava flows and all of that,” which I had not seen before, coming from Pennsylvania. So I did site testing down there, for what became Mauna Kea Observatory.

Some years passed, and that turns into a big world-class observatory. By the 1980s, Dale Cruikshank, my buddy who had worked on the spectrometers for Kuiper, had gone off to the University of Hawaii and is doing infrared spectrometry, and following exactly the footsteps that Kuiper had trained him in.

Mel Simmons, on the construction of the 61-inch telescope

I came in ’64 at the request of Dr. Kuiper, because the construction of what we call the 61-inch, later referred to as the 1.5-meter, had been stopped. The U of A had more billings than money available to complete the telescope. So the Comptroller’s Office stopped construction and said, “No more work until we see what’s going on.”

Kuiper called me, and I went in and took the job to see what was going on. I worked over in the Comptroller’s Office for about a month. I got a copy of the contract with Western Gear because that’s where the problem was, with the telescope itself. Not with the dome, but the telescope. I went over every invoice from the time it started to where they stopped it, and then I classified all the invoices paid or not paid, as well as what I thought were erroneous billings.

Anyway, I spent about a month going through all the invoices, and then I told Sherwood Carr who was the Comptroller at the time that I was going to call Western Gear, the contractor, and tell them I would like for them to send a man over to go over every invoice, one with the authority to void an invoice. I spent about three weeks with him, and he agreed with me, and okayed all the ones I said were okay and voided all the others.

Anyway, to make a long story short, we finished the construction. Kuiper had an optical professional from Scotland [Robert Waland] to grind the mirrors that was to be in the telescope. We made the mirror in the basement of the Space Science building. Probably the instruments used for the grinding are still in the basement. When Astronomy got in on it later in the years—because they wanted to put all the telescopes together—they referred to it as a 1.5-meter.

We had enough money left to do the dormitory. We went ahead and started construction, and because we didn’t go through Physical Resources they wouldn’t furnish anybody to look at the construction and see if it was being followed the way we had it outlined. So I used Arnold Evans, who was in charge of the observatory facilities, to check all the construction because I was down here and didn’t go up there that often.

He did a great job. We finished the construction of the dormitory; we still had a little bit of money left over. So I talked to the contractors that built these cabins, and he gave me enough—just gave it to me—enough redwood to cover the steps. The telescope was up above and the dormitory was down, behind it, on the North side. So we had to have steps, and in the wintertime those would be covered with snow, and a tired man observing was liable to slide all the way down. So we covered the steps with redwood and made it safe.

Later we built another telescope up there, a small one, for Dr. [Elizabeth] Roemer. Dr. Kuiper was spending most of his time trying different areas, testing them, and some of the areas he tested were Pikes Peak, Colorado, and Flagstaff. He went over to where the University now has telescopes on Mt. Graham, and he did a test there. As I remember, Dr. Kuiper felt there was a little bit too much moisture as far as he was concerned, so he dropped that.

But then he went to Hawaii, Mauna Kea. We took a 21-inch telescope over there, about halfway up the mountain, where he did a lot of testing. He talked NASA into building the telescope that’s there, through the University of Hawaii. He then tested the Mexico site for a telescope. We built a road to the top so he could test the site. He put a 21-inch telescope up there for testing; later on they had their telescope up there.

After Dr. Kuiper left, he still went on to do all this testing. We have the radar site that’s up on Mt. Lemmon itself. It was owned by the Forest Service. But the military had it as a radar site and there were a couple of radar buildings up there. I went out and talked to the DM because I was in the materials division of the Air Force and I was in the Army Air Corps then; it’s just Air Force now. I went out and talked to them and they gave me a letter releasing the site, to the University. Then I went to the Forest Service and they approved it.

We took over their buildings and they’re still there. There were two domes that weren’t quite what you’d want for an observatory, but they still worked fine for infrared, and that’s what we had to do. We got tractors and snowplows and trucks and trailers and stuff we needed when we were doing all this testing of different sites for Kuiper. One of the tractors went to Mexico when Arnold Evans built the road up to the top. That’s where they have their telescope now. I think the 21-inch is still about halfway up to Mauna Kea, before they get in to where they need to have oxygen. That’s where he did his testing and found it to be great.

That’s the reason I came in was to get the construction of the Kuiper Telescope—then the 61-inch—done and completed. I think there’s probably a 21-inch telescope in Flagstaff, too; I think he left one there. You’ll find them all over. I think there’s one in Flagstaff, one in Hawaii, and one in Mexico. He used them for testing.

Ewen Whitaker, on the 61-inch telescope

In the earlier days, when we first got the telescope going, in order to have the eyepieces together I’d got a “Saniflush” box, a junk box, made into a thing with holes so the eyepieces would sit in it. I believe it’s still up in the dome. Completely wrecked, I’m sure. You’d think, okay, we’ve got these highly expensive eyepieces, let’s make a nice box for them, a wooden box. Was it ever made? No.

George Coyne, on the consolidation of the telescopes

Up until that time all the telescopes had been naturally under the administration of the Astronomy Department. When Kuiper came he got NASA funding to build what was then a major telescope, which is still there near Bigelow Mountain. The 61-inch it’s called. That was built to be a high-quality imaging telescope for the Ranger program, to map the Moon to select the sites. Of course that came under the administration of LPL, and eventually the Department of Planetary Sciences.