Chapter 3: The flying ash can
Theme: Describes the process by which the spacecraft design was determined during the period after Sputnik I. Main characters: Faget, Mathews, Heberlig, Eggers, Hammack.
“How can it be a bird if it doesn’t have wings?” Certainly Mercury was one of the strangest-looking devices for human transportation ever conceived. The first manned space vehicle had to be a cross between an airplane and a missile, but finding the proper cross was a difficult problem. Those engineers whose experience was primarily in aviation felt that a space vehicle should have some sort of wings, so that it could make a landing like an airplane, and so that it could use the atmosphere to maneuver and pick its touch down point. In an effort to design such a vehicle, literally hundreds of different shapes were evaluated in wind tunnels -- designs that looked like tear drops and slightly smashed ice cream cones, to designs with folding wings which could be opened as the vehicle came close to the earth. But all of these flying models had one basic problem -- they were too heavy. Our ICBMs had been built just large enough to carry highly refined atomic warheads. Therefore, they were very limited in the load they could carry. But there was no time to build a new rocket. We had to use the one we had, or accept a long delay in achieving manned flight.
Max Faget came up with the answer. The astronaut was not flying -- he was being shot like a bullet, and his spacecraft would have to look something like a bullet. There was one major problem. Elaborate computer calculations of the flight path indicated that in emergencies the astronaut might have to withstand as much as twenty times the normal load of gravity. For a few seconds a two-hundred-pound man would weigh over two tons. Could any man survive that? “No” was the answer that came from the Air Force. Their standard doctrine was that no man should be asked to take more than twelve g. How could you protect the man against this tremendous load? Some medical specialists had proposed putting him in a water bath in order to equalize the pressure around his body. But this was impractical for space flight.
Perhaps the next best thing would be a closely contoured couch, molded to the astronaut’s body. In July 1957 Max Faget and Jack Heberlig took a couch which had been molded to the body of a test pilot to the Johnsville centrifuge and made a series of runs beginning with low acceleration and gradually working up. 12, 14, 16, 20 g! The pilot had to work hard to control his breathing, but otherwise he was all right. He could watch instruments and make radio reports, even when his body was twenty times its normal weight. Max Faget’s basic concept had been demonstrated. Project Mercury could get underway.
Many other problems remained to be solved: the problem of providing a means to escape an exploding rocket; the means by which the attitude of the spacecraft was to be controlled in space; how to provide a livable atmosphere for the astronaut in the void of space; how to provide a door which could be securely closed and yet would open rapidly in the event of emergency; how to deploy the parachutes reliably at just the right altitude; how to cushion the astronaut's fall; how to keep the spacecraft floating once it had landed in the water. Solutions were needed for these and many other questions. All involved a number of possible approaches which were argued vigorously, studied carefully, and usually settled by exhaustive tests.