Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.jsc.nasa.gov/history/oral_histories/RiedRC/RiedRC_2-7-02.pdf Дата изменения: Thu Jul 11 00:36:25 2002 Дата индексирования: Sun Apr 10 01:56:50 2016 Кодировка: Поисковые слова: meteor shower

NASA JOHNSON SPACE CENTER ORAL HISTORY PROJECT ORAL HISTORY TRANSCRIPT
RT C. RIED, JR. INTERVIEWED BY KEVIN M. RUSNAK HOUSTON, TEXAS ­ 7 FEBRUARY 2002

ROBE

RUSNAK: Today is February 7th, 2002. This interview with Bob Ried is being conducted in Houston, Texas, for the Johnson Space Center Oral History Project. The interviewer is Kevin Rusnak assisted by Sandra Johnson and Jennifer Ross-Nazzal. Thank you for taking the time out to spend with us this morning.

RIED: My pleasure.

RUSNAK: Good. Well, if we can start out, tell me about any interests you might have had in aviation or science growing up, the kinds of things that might have led you on to a career path that took you to the space program.

RIED: Well, my father was an engineer. He passed away when I was very young, but I felt like I wanted to be an engineer. He was a practical engineer. He had his own company. So when I went off to college, I focused on being a practical engineer and particularly in materials metallurgy, which is part of his expertise. I discovered that I'd probably be fifty years old by the time I was an expert in that area, so I slowly became, if you want, more interested in science, more theoretical things. I had very little money. I was interested in pursuing graduate work. I also had a girlfriend. I was going to get married. So I was looking for a position for a couple of years to

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make some money and then go back to graduate school. I had used some NACA [National Advisory Committee for Aeronautics] reports in my work in undergraduate school, and I was very impressed with those reports. They were sort of in between the journal articles and textbooks, and they were very complete. Of course, Sputnik had come along and space activity was starting, but I was so focused on my studies, I really wasn't aware of the broader world at the time, you might say. I was interested in doing research and gaining an understanding of things. When I interviewed NASA, I looked at it as the NACA. Like I said, I was interested in doing research, so I asked if that's what I'd be doing and was told yes. So I accepted a job offer with them. It was not the most lucrative, but it seemed to be the best foundation for what I thought I wanted to do. Came to work at the Space Task Group at Langley [Research Center, Hampton, Virginia] and at the time I didn't realize the difference between the Space Task Group and the Langley Research Center. I was interested in doing research. So after a few months when I figured all this out, I was trying to transfer to the Langley Research Center and had a very interesting opportunity there. But Bob [Robert E.] Vale, Aleck [C.] Bond, called me in and said, "You don't want to do that. We've got some real challenges here in space flight." They interested me in a particular challenge on the Apollo. By the way, my very first job when I went to work was working on the Apollo. That was in 1961. It was sort of, well, looking at the configuration and the

aerodynamics, but I had no view as to what Apollo was to become at the time. In any event, there had been some newspaper publications that one could not bring men back from the Moon because of the thermal radiation from the gas cap. It was a nonequilibrium

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phenomenon, which I had done a little work in nonequilibrium when I was an undergraduate, and it was a real challenge. They said, "Your job would be to take two years and understand this phenomenon and let us know, indeed can we come back from the Moon or will it burn up the capsule or whatever. We don't really understand what this is." That was exciting, and also the time frame was right, because I wanted to go back to graduate school. So I started to pursue that. There was a contract that had already been under way to AVCO [Corporation] Everett [Massachusetts Division] research organization, which was an outstanding small elite research organization. They had shock tubes that were far in excess of anything that NASA had at the time and were most appropriate for understanding or doing diagnostics on very strong shock waves. Briefly, at equilibrium for Apollo entry, the gas cap at equilibrium is about 10,000 degrees Rankin or 6,000 Kelvin. That's equivalent to what the apparent temperature of the sun is; that is, the sun's radiation is like black body radiation from about 10,000 Rankin. So the equilibrium temperature of the gas in front of the capsule coming back from the Moon was basically the same as that. But the nonequilibrium temperature right behind the shock, if one does a quick calculation, is like a hundred thousand degrees. That is what gave rise to the predictions that the radiation from that high temperature would burn the capsule up. Well, it turned out to be very interesting phenomena. There were diagnostics made at AVCO and other places, but primarily at AVCO that could get the higher shock speeds, characterizing the radiation behind the shock. What happened was the temperature indeed went to very high value, but all the energy was in translational form, not in the excited states that are needed to radiate. So the radiation, indeed, would shoot up and exceed by two orders of magnitude the radiation from the equilibrium gas, but it happened very quickly, and so the total

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integrated radiation coming to the capsule was limited. It turned out actually that the equilibrium radiation was more important to the heating to the capsule, comparable to the convective heating, which was all new at these high velocities, if you want. So my first real challenge was to understand that. AVCO did all the real work. They took the data, did the basic analysis, but the idea was for me to take that basic information and apply it to the entry of Apollo and understand what the heat transfer would be so that we'd understand better what the thermal protection or the ablator characteristics had to be. So that was my first job, and it was a lot of fun. I really enjoyed it. I felt like indeed I was contributing, although once we understood it, there was no doubt that we could bring people back from the Moon, but initially there was a question, like lots of other questions. It was also the first time I ran into the bureaucracy, if you want. This contract had been in place prior to my joining that particular group, and it ran for two years to get adequate data to understand that, which was my time constant for understanding it. As I mentioned before, we then understood that the equilibrium radiation was more important to the heat transfer and we needed an accurate assessment of that radiation for the heat transfer to the capsule. So I'd asked for an extension of the contract to AVCO to get some additional spectroscopic data and characterize the equilibrium radiation. Well, I don't remember the details, but it turned out that someone in Washington had decided--and at this point we had moved to Houston, it was the Manned Spacecraft Center-- that we don't need some young kid at MSC monitoring a contract with these great people at AVCO. This is mor