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Additional Remarks About the Reentry Story by Dr. George W. Sutton :
Rose and Stark published measurements of heat transfer in dissociated hypersonic flow (Journal of the Aeronautical Sciences, Vol. 25 pp.86-97). This is in Hayes book on hypersonics.
This was a great issue in the Atlas ICBM program. The original contractor, Convair in San Diego, had been analyzing the heat transfer using the properties of undissociated air (Doran?) The progress on this was reviewed by a committee on which was Kantwowitz. He objected to their theoretical treatment; and the Air Force decided to separate the nose cone from the rest of the program.
Kantrowitz then managaged a meeting with Victor Emanuel, then Chairman of Avco, at a reception at Cornell, where K. was a prof. and V.E. was on the board of trustees. K. mentioned to V.E. the separation of contracts, but that the key issue was the heat transfer to the nose cone due to dissociated air; namely, whether the NO which formed would have a large f number and its radiation would be perhaps greater than the convective heat transfer. Here, the shock tube would settle the issue, which it did. Emanuel formed AERL with Kantrowitz as director, and obtained A.F. funding for it. (Later. Wally Warren at G.E. and Pete Rose at AERL would build shock tunnels which more fully simulated the hypersonic aerodynamics.
K's interest in shock tubes stemmed from his first job out of Columbia U (PhD student under Teller, on N2 vibratin relaxation) was at NACA Langley. Jacob Eastman was his superviser. He had read Bethe's stuff on the hydrogen fusion of the Sun and wanted to simulate it in the laboratory and gave that task to K. K tried plasma discharges and became an expert blower of glass. He then thought that maybe a shock tube would do the job - which he built. It was, of course, ideal for raising air to high pressure and temperatures, hence the connection. Sadly, Eastman Jacob lost his job at Langely due to a marital infidelity affair.
Anyway, the f number of NO was small and did not contiribute much to the heating for reentry conditions.
A Rand Corp. report (in about 1954) stated that using known materials, ICBM reentry would not work. Professor Theodore Von Karman described it as a real challenge.
The solution for the Atlas ICBM was going to be a copper heat shield with low beta.(weight divided by drag coefficient times area) For this, G.E. won the reentry systems contract based on copper; for which they promised that Guy Suits, head of G.E.'s research laboratory, would work half time. He never did.
Dr. Leo Steg, a systems engineer at GE optimized the shape of the reentry vehicle and heat shield and later discovered that it could not fly 5,000 mi because of tripping to a turbulent boundary layer with greatly increased heat transfer. (He is now deceased)
Simultaneously, the G.E. systems engineers requested the development of a "data" capsule that would be inside of the copper heat-sheilded reentry vehicle, to record the sensor data that could not be transmitted during reentry due to plasma shielding. It was to be popped out and recovered separately (water landing).
I was asked to develop the heat shield material for the data capsule. Ceramics seemed too brittle, and graphite had too high a thermal conductivity and could heat the structure underneath. I had heard about some GE work on using reinforced plastic laminates for jet-vanes for the Hermes rocket that they were developing. However, they delaminated. I thought that if the fiber could be placed randomly, then it would not delaminate. So I had built little 1" models of this with thermocouples and had them tested at the G.E. Malta rocket test station, in a rocket exhaust. I gave my paper in June 1957 on the results, and Dr. George Solomon, chief engineer of Ramo-Wooldridge, stood up and said that is the answer. In Oct 1957, General Shriever (who was in charge of the Air Force ballistic missile program) ordered that all of the G.E. work on ablation be turned over to Avco. Then the RVX series was started. The heat shield for the first one used three of the materials I had tested, and successfully reentered. Avco supplied a different heat shield which was put on the GE RVX airframe, but this time with a recovery package, recovered ~ April 1959. Wally Schafer of G.E. was the engineer for the RVX series. Incidentally, the textbook on plastics that I used was written by Prof. Herman Mark of Brooklyn Polytechnic; He was the father of Hans Mark.
The Avco material was called "Avcoite." The ex-director of Avco's research lab has told me it was not my material, but quartz (the melting of which I had also analyzed). So I became curious, and working with the Smithsonian curator, recently found the nose part in a warehouse. (The rest of it is on exhibit, and indeed, it is reinforced plastic - probably with the same 91 LD phenolic that I used.) It turns out that the nose tip is a sphere cone. The conical part is also reinforced plastic, but the spherical part of the nose is a glassy material embedded in a metallic honeycomb with about 1 cm spacing. This construction method was confirmed to me last month (February 2005) by Peter Rose, who was working at Avco at the time.
Subsequent reinforcements were Nylon, quartz, and now carbon fiber (the latter on the ill-fated Columbia wing leading edges).
The Army, for Jupiter, chose tiles of laminated reinforced plastics. Although the first short range flight was a success, with a letter inside personally delivered to President Eisenhower, subsequent flight reentries had many failures, possibly due to delamination of the laminate tiles.
The Mark 12 nose tip was made of graphite, for which there were problems. This caused the birth of the high energy laser program. I was working at Avco at the time, and there was a Mark II gas dynamic laser (a name I coined) generating about 8 kW. This work was supported by DARPA under the name "8th Card." It had many review committees, all of whom were against a scale-up because of various imagined problems, like turbulence. So I came up with a conceptual design of a 100 kW unit and took it to the Air Force and briefed Col John Anderson on it. He asked me if I could tell the story to his advisors (Aerospace Corp), and I agreed - he already had them in the next room! (One of them was Dr. Harold Mirels.) It was funded within 10 days. It was built by Arne Mattson of Avco. The first test of it was an abort (the igniter did not fire), but on the second try, it generated 140 kW. So now the country knew that high energy lasers could be built.
The tragedy of the Columbia need not have happened. I was on a National Research Council, reviewing Shuttle safety and upgrades. Absolutely no one told us that insulation was flying off the external tanks and hitting the Shuttle!
The Corona Project also used my material for the film recovery capsule. I am still trying to find out more about the SAMOS, which may have been built by a different contractor. Both projects were in the Air Force Western Development Division.
My paper, "The initial Development of Ablation Heat Protection, an Historical Perspective," J. Spacecraft & Rockets, Jan-Feb, 1982 contains many references. Some are listed below:
Aerodynamic Heating –The Temperature Barrier in Aeronautics", Proceedings of the Symposium High Temperature – A Tool for the Future, Berkeley, Calif. June 1956, Sponsored by Stanford Research Institute and University of California
Sutton, G. W., "The Temperature History in a Thick Skin Subjected to Laminar Heating During Entry into the Atmosphere," Jet Propulsion, Vol. 28, Jan. 1958
Adams, MacC. And Scala, E., "How Avco Developed Ceramic Heat Shielding for ICBM Reentry Vehicle," Ceramics Industry, April 1960
Rose, P. H. and Stark, W. I., " Stagnation Point Heat Transfer Measurements in Dissociated Air," Journal of the Aeronautical Sciences, Vol. 25 Feb. 1958
Scala, S. M. and Sutton, G. W., "Vectored Injection into a Hypersonic Laminar Boundary Layer," Jet Propulsion, Vol. 27, Aug. 1957
Sutton, G. W. " Combustion of a Gas Injected into a Hypersonic Laminar Boundary Layer," Proceedings of the Seventh Symposium (International) on Combustion, Butterworths, London 1958
Scala, S. M. and Sutton, G. W., "Energy Transfer at a Chemically Reacting or Slip Interface." American Rocket Society Journal, Vol. 29 Feb. 1959
Sutton, G. W., "The Hydrodynamics and Heat Conduction of a Melting Surface," Journal of the Aeronautical Sciences, Vol. 25 Jan. 1958
Scala, S. M. and Sutton, G. W., " The Two Phase Hypersonic Laminar Boundary Layer – A Study of Surface Melting," Proceedings of the 1958 Heat Transfer and Fluid Mechanics Institute, Stanford University Press
Bethe, H. A. and Adams, MacC., "A Theory for the Ablation of Glassy Materials," Journal of Aero. Space Sciences, Vol. 26 June 1959
Schmidt, D. L., "Hypersonic Atmospheric Flight," Environmental Effects on Polymeric Materials, Interscience Publishers, New York, 1968
Christensen, D. and Buhler, R. D., "On the Stable Shape of an Ablating Graphite Body," ," Journal of the Aeronautical Sciences, Vol. 26 Jan. 1959
Sutton, G. W. On the Stable Shape of a Slender Ablating Body," Journal of the Aeronautical Sciences, Vol. 26 Oct. 1959
Scala, S. M. and Gilbert, L. M. "Sublimation of Graphite at Hypersonic Speeds," AIAA Journal, Vol. 3, Sept. 1965
Nolan, E. J. and Scala, S. M., "Aerothermodynamic Behavior of Pyrolytic Graphite During Sustained Hypersonic Flight," American Rocket Society Journal, Vol. 329 Jan. 1962
"Protection Potential of Several Ablation Materials for Satellite and Ballistic Reentry into the Earth’s Atmosphere," Ballistic Missiles and Space Technology, Vol. II, Pergamon Press, 1961. My analysis also appears as Eqs. 1-9 and Fig. 5 in American Rocket Society Journal, Vol. 30 Sept. 1960 pp. 815-822.
Georgiev, S. Hidalgo, H. and Adams, M. "On Ablation for Recovery of Satellites," Proceedings of the 1959 Heat Transfer and Fluid Mechanics Institute, Stanford University Press
Scala, S. M., "A Study of Hypersonic Ablation," , Proceedings of the Xth International Aeronautical Congress(1959) Vol. II, Springer-Verlag, Berlin, 1960
Tellep, D. M., "{ The Effect of Vehicle Deceleration on a Melting Surface," Journal of the Aeronautical Sciences, Vol. 26 Aug. 1959
Kadanoff, L. P., "Radiative Transport Within an Ablating Body," Avco Everett Research Laboratory, Research Report 37, Oct 1958
George W. Sutton, Ph.D., NAE
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