Read Apollo: The Race to the Moon Online

Authors: Charles Murray,Catherine Bly Cox

Tags: #Engineering, #Aeronautical Engineering, #Science & Math, #Astronomy & Space Science, #Aeronautics & Astronautics, #Technology

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According to Johnson, things were going fine until they got a call from von Braun saying that Marshall had reduced the diameter of the third stage to 154 inches. “We said, ‘Jesus Christ, now we can’t leave this sonofabitch hanging out over the edge like that, and we can’t change the mold lines, because that’ll cut in on the interior space.’ So we said to each other, ‘Let’s just round the corners, nobody’ll ever know the difference.’ And that’s how that command module got rounded. I don’t doubt that the rounded corners are very beneficial and all that, but that was not the driving reason when it was done.” Owen Maynard saw another benefit. He knew from experience that whatever design they submitted would inevitably accumulate weight as time went on, eventually reaching “the density of water.” The only way to limit the weight was to limit the amount of space that the engineers could stuff things into. Rounding the corners helped.

To add to the irony, all that fiddling would have been unnecessary had they procrastinated a few more months. After struggling to make the capsule fit a Saturn that had been reduced from 160 inches to 154 inches, Marshall changed its mind again and replaced the planned third stage with another, larger one. The Space Task Group could have made the volume of the spacecraft just about as big as it wanted, after all; but by that time the design had been locked into the 154-inch configuration. This is why the adapter atop the third stage of the final Saturn/Apollo stack slanted inward—to make the rocket diameter small enough to fit the spacecraft diameter that Johnson and Faget had struggled to reach.

Because Apollo’s basic design was laid out before the lunar landing mission had been given to it, the spacecraft did not have the capability to get down to the moon’s surface and up again. As talk about a landing mission became more explicit, Johnson went to Owen Maynard one day and told him to put his Systems Integration Section to work devising a spacecraft capable of a lunar landing and liftoff. But as Maynard and his team went to their drafting tables and began to try out ideas, it soon became apparent that designing such a vehicle would be a bafflingly difficult thing to do. The usual assumptions about how man was going to land on the moon didn’t seem to work very well.

2

For many years, small boys pretending to be Buck Rogers knew exactly how to get to the moon. First you got a big rocket with fins on it that took off from earth, and then when the rocket got close to the moon you turned it around and used its rocket engine as a brake. You got out and climbed down a ladder, explored for a while, climbed back up the ladder, and took off for earth. When you got close to the earth, you did the same thing all over again. In the parlance of Apollo, small boys pretending they were the first man on the moon opted for the direct ascent mode.

In 1952, a new idea was shown in spectacular full-color pictures in the Collier’s issue of March 22. A panel of scientists headed by Dr. Wernher von Braun told how a space station, a great spinning shining ring, filled with workshops and living quarters and observation posts, with artificial gravity, serviced by a fleet of space tugs, could be built within the next ten to fifteen years. Among other things, such as promoting world peace (“It would be the end of Iron Curtains wherever they might be”), the space station would be an intermediate step for getting to the moon. A spacecraft would be assembled in space, using components launched separately from earth. This new way of getting to the moon (minus the great spinning space station) would become known later as the earth-orbit rendezvous mode, or E.O.R.

The advantage of E.O.R., when NASA came to study it, was that it required a smaller launch vehicle than direct ascent. The vehicle that landed on the moon (it was assumed) had to be a large, self-contained rocket system, complete with crew quarters, onboard life-support systems, equipment for exploring the lunar surface, enough fuel to escape the moon’s gravity for the return to earth, and a heavy heat shield for surviving the 25,000-m.p.h. entry into the earth’s atmosphere. Lifting that much weight in a single launch called for a mammoth vehicle. If instead the spacecraft could be launched from earth in two or three components and assembled in earth orbit, the lunar enterprise immediately became much more realistic.

The disadvantages of E.O.R. were considerable, however. First of all, how easy was it to rendezvous in space? In the early 1960s, no one knew yet. But presumably those difficulties could be overcome “Rendezvousing in earth orbit was not the problem,” Faget explained, “but the business of, after you rendezvous, how do you put together the wherewithal to go to the moon?” At the time of Kennedy’s speech, two main variations were being considered. In one of them, the propellants for the lunar journey would be put into orbit by one Saturn V, then a complete but unfueled spacecraft would be launched by another Saturn V. Another variation called for the spacecraft itself to be launched in segments and assembled in space.

These sounded straightforward enough, but actually doing them would be a tricky business. If the E.O.R. scheme called for rendezvousing with the propellants, then exactly how could they transfer these large quantities of volatile liquids from the storage tanks to the spacecraft in the weightlessness and vacuum of space? And if instead the E.O.R. scheme called for putting the spacecraft up in two or three segments, what were the actual engineering devices whereby these segments were to be connected in outer space, ready for a lunar voyage? “Every time you’d tell them what was wrong with one way of doing it, they’d tell you, well, they were going to do it the other way,” Max Faget recalled. “As far as I know, those problems never got solved.” For a long time, direct ascent still seemed simpler than E.O.R.

Furthermore, by the early 1960s direct ascent was no longer an impossible dream. The F-1 engine for powering the Nova, the same engine actually used for the Saturn V, was already in development by the time of Kennedy’s speech. Von Braun’s rocket scientists had the booster itself, called Nova, on their drawing boards. It was mammoth. In one typical configuration, Nova was to have eight engines clustered in its first stage (the Saturn would have five) developing 12,000,000 pounds of thrust, a second stage with four engines developing 4,800,000 pounds of thrust, and a third stage with 200,000 pounds of thrust. By way of comparison, the shuttle has a total liftoff thrust of about 6,400,000 pounds, only a little more than half the thrust of the Nova’s first stage alone.

Many people in NASA thought the Nova should be built (Faget was an especially enthusiastic proponent), and as late as June 1961, when the Fleming committee submitted the first post-speech plan for Apollo, the recommendation was for a Nova configured in three stages, capable of boosting 160,000 pounds into orbit. Once again, Owen Maynard saw an indirect benefit to supposedly scientific logic: If they had not been talking about the Nova, the huge Saturn would have seemed impossible. “The fact that we could postulate Nova with somewhat of a straight face automatically made the five-eighths-size Saturn credible.” It is one of the tricks engineers sometimes use on themselves, Maynard said, to maneuver themselves into taking on tasks that would otherwise be terrifying.

But there were daunting obstacles to actually building Nova. “It would have damn near sunk Merritt Island,” one engineer observed of Nova, not entirely kidding. The designers of Nova weren’t even sure that they could launch Nova from a land-based launch pad because of the noise and vibration it would generate. They were thinking about launching it from barges built several miles offshore from the Cape. It was this kind of complication that kept getting in the way of making the decision for Nova. It seemed to be an unearthly vehicle in many ways.

Oddly, it was Marshall that took the lead in opposing Nova and supporting E.O.R. in its place. Nova had an obvious attraction for the people at Marshall —it would have been the ultimate new toy for people who loved to design rockets. Nonetheless, they preferred the Saturn. Earth-orbit rendezvous would still require a huge booster, but Saturn-sized. Von Braun argued, with growing support, that E.O.R. would be a faster, surer way of getting to the moon.

Some of the people in the Space Task Group, which was favoring direct ascent, suspected ulterior motives behind Marshall’s position. Earth-orbit rendezvous would multiply the number of launch vehicles that would be needed, thereby increasing Marshall’s role. But the argument openly used by von Braun and his people was plausible: Going directly from Redstone and Jupiter vehicles to the Nova was too big a step. Building Saturn seemed to be a much more orderly and prudent advance in rocket technology.

3

Whichever way the choice went, direct ascent or E.O.R., the problem facing Maynard and his team was the same. Whether it was lifted in one piece or assembled in earth orbit, the spacecraft had to be able to escape Earth’s gravitational field, cross 240,000 miles of empty space, execute a landing on a surface of uncertain terrain and composition, execute a liftoff from the lunar surface without ground support, survive entry into the earth’s atmosphere, and then serve as a boat after it landed in the ocean. It was one thing to talk about such a vehicle in the abstract; it was quite another to create one that an astronaut could actually fly.

“As an example,” Maynard said, “for launch, you wanted the guy lying on his back so that the escape system could haul him away from the launch vehicle at as high an acceleration as he could stand.” They also had to be watching their displays, so that they could monitor all the command module’s systems. They had to be able to look out a window, so that they could see a horizon and have secondary sources of information about the attitude of the spacecraft.

The difficulty the designers faced was to make the resulting layout (about which they had virtually no choice) work when the spacecraft came in for a landing on the moon. At this point in the flight, as Maynard described it later, “I want the guy to be able to see where he’s landing, to be sitting upright with his spine aligned with the engine axis. That means I’ve now got to turn him around ninety degrees, and reorient his displays and controls. This made you have either very complex arrangements of displays or two sets of displays.” Maynard and his people tried everything, including swiveling couches and displays. Nothing worked. “There’s no way you could see the surface all the way down without putting the astronaut out on a porch,” said Faget. “So it was a hard spacecraft to land if you wanted to eyeball it, and there was certainly every reason to believe that the astronauts would insist upon having eye contact with the surface at the time of landing.”

As the options diminished, they finally were driven to thinking about giving up eye contact with the surface, but it never got far enough to take to the astronauts—none of the designers really wanted to do it. “But that was the only other alternative,” Faget said. “So we were really at an impasse.” Maynard felt he was trying to overload the spacecraft with functions.

They did manage to come up with some designs that were supposed to be able to do the job, but all of them were getting too big and awkward and heavy. “It was like landing a Mack truck instead of a small sports car,” said Maynard. And landing was only the half of it. Assuming you got down in one piece, there was still the problem of lifting off. “It just got dicey as hell,” said Caldwell Johnson. “That stage that landed was a big clumsy thing… . If you land with the cylinder upright so you can take off again, the sonofabitch will fall over. And if you land it flat, it won’t take off again. So it wasn’t only the crew’s position but all the mechanics of the whole thing. We had more harebrained schemes than you could shake a stick at.”

For Walt Williams, in charge of trying to launch the Mercury astronauts on the Atlas even as the Apollo concept was being developed, the whole thing began to take on an ominous parallel. The spacecraft that Johnson and Maynard were coming up with was about the size of an Atlas, ninety feet long, and Williams shuddered at the notion of “backing an Atlas back down on the pad.” They were having enough trouble getting the Atlas to go the other way, he thought, without trying to land one.

Finally they moved toward a scheme that solved some of the technical problems. Instead of trying to land a ninety-foot-long cigar on the surface of the moon, they would build a “lunar crasher.” The assembly would consist of a command module with a comparatively small engine and propellant tank, along with an additional stage especially designed to take out most of the velocity on the descent. The additional stage—the crasher—would slow the rest of the spacecraft until it had reached an altitude of about 10,000 feet above the surface and a velocity of 1,000 feet per second (about 680 m.p.h.). Then—and here things got a little tricky—the crasher would separate and crash onto the lunar surface, leaving the rest of the spacecraft to use a smaller, lighter descent engine to get the rest of the way down on its own.

Hairy as it sounded, the lunar crasher was the most plausible arrangement they came up with. “We went to headquarters and argued long and hard for the lunar crasher,” said Faget, “and as a matter of fact we did sell the concept.” But it was so cumbersome, so inelegant, so downright ugly. None of their schemes, including the lunar crasher, gave Maynard that warm feeling that he liked to have about a design.

Chapter 8. “Somewhat as a voice in the wilderness…”

Tom Dolan’s team at Vought Astronautics was the first to come up with the notion of using a second spacecraft to descend to the lunar surface.* Dolan, a farsighted fellow, read the accounts of the new Project Mercury in December of 1958 and decided that it would surely be followed by something more ambitious. He assembled a team of engineers at Vought to try to get a head start on the competition. By the middle of 1959, they were already concentrating on how to get to the moon.

[* Historians have found earlier references to the lunar-orbit rendezvous concept. Yuri Konratyuk, a Russian rocket theoretician, had written a paper suggesting an analogous scheme back in 1916, and H. E. Ross, a British scientist, had described one in 1948. The people who worked on the lunar-orbit idea in the 1950s do not seem to have been aware of this work. Dolan’s team gets credit for being the first to propose lunar-orbit rendezvous after a lunar landing became a live technological possibility.]

BOOK: Apollo: The Race to the Moon
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