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

Apollo: The Race to the Moon (17 page)

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The chief barrier to getting to the moon and back again was the energy budget. Putting a pound of payload into earth orbit takes a lot of energy coming off the launch pad, which means a lot of propellant; taking a pound all the way to the moon requires that much more; taking a pound all the way to the moon and back again requires the most of all. Dolan and his men developed a solution: Design the spacecraft so that you can throw away parts of it as you go along. The Dolan team called it a “modular” spacecraft, in which different segments were designed exclusively for certain tasks. When the task of one module had been completed, it would be detached from the remainder of the spacecraft and discarded, ending its drain on the energy budget.

In exploring how to make the most efficient modular system, someone in the team came up with an idea that was not at all obvious: After you had gotten the spacecraft out to the moon, suppose that you didn’t land the whole thing? Suppose that instead you designed a second spacecraft exclusively for the purpose of going down to the lunar surface and returning to the mother craft?

They ran the idea through their slide rules and came out with revolutionary results. A second spacecraft built specifically for the lunar landing would not have to carry the heavy heat shield necessary for entering the earth’s atmosphere—a big savings. It wouldn’t have to carry the propellants for returning home—another big savings. A lunar lander could be constructed of light materials, because it wouldn’t have to contend with much gravity (only one-sixth of earth’s) and would encounter no atmosphere at all. The weight savings of this method were enormous. There was one difficulty, however. To take advantage of this method, the astronauts on the moon would have to rendezvous successfully with the mother craft orbiting overhead, and no one knew how to do that yet. Furthermore, the rendezvous would have to be conducted 240,000 miles out in space, far from any hope of rescue.

At about the same time Dolan was putting his team together at Vought Astronautics, a Langley engineer named Clint Brown believed, mistakenly, that a new little rocket called the Scout might be used to put a two-pound payload into orbit around the moon. He and his colleagues began to play with lunar trajectories. They soon realized that they could never use the Scout for that purpose, but they had become intrigued with the problems of lunar trajectories and continued to work on them. “We had a very nice competition going between the two divisions at Langley,” Brown recalled, with John Bird over in the Flight Research Division and Bill Michaels in Brown’s own Theoretical Mechanics Division working through the theory of getting into and out of lunar orbit. After a while, they began to postulate manned spacecraft in their theoretical analyses.

Early one morning in February 1960, Bill Michaels came into Clint Brown’s office with some new calculations on what they were calling a “lunar parking orbit” for use in a manned landing. Michaels’s figures indicated weight savings far beyond anything they had realized before. This looked really interesting, they agreed. They ought to get out and tell someone right away. And at 10:00 that very morning, Brown would recall ruefully, they were scheduled for a presentation by a team of engineers from Vought led by Tom Dolan. “And, darn, they got up there and they had the whole thing laid out. They had scooped us. Bill was going around with his face hanging down to the floor.”

Michaels went ahead and wrote up their analysis in a Langley working paper entitled “Weight Advantages of Use of a Parking Orbit for Lunar Soft Landing Mission,” which Langley circulated in May 1960. At about this time, another name for the technique began appearing—lunar-orbit rendezvous, or L.O.R. But at that time only a handful of people in NASA were thinking seriously about a lunar landing anyway, and no one paid much attention.

Even after NASA did begin to think seriously about a lunar landing in late 1960, no one would take L.O.R. seriously. An engineer from the Instrumentation Laboratory at M.I.T. remembered being down at Langley during this period. Someone there described to him this idea of detaching a little bug from the main spacecraft. The engineer went back to M.I.T. and told his colleagues “about this nut who had suggested such an outlandish thing, and we all chuckled.” That’s what everybody thought the first time they heard it: Those guys couldn’t possibly be serious. “It’s like putting a guy in an airplane without a parachute and having him make a midair transfer,” John Disher scoffed to John Bird. No, Bird replied, it’s like having a big ship moored in the harbor while a little rowboat leaves it, goes ashore, and comes back again. But no one was persuaded.

1

If it hadn’t been for John Houbolt, that might have been the end of it.* The Langley engineers on Brown’s team had done what Langley did best. They had explored an interesting research problem, prepared a technically careful discussion of it, and published the results in a Langley paper. If the practitioners cared to use their work, they were welcome to it. If not, that was their business. But by that time John Houbolt had gotten involved.

[* Herein lies contention. In 1969, at the time of the first moon landing, Life magazine ran a long article that portrayed John Houbolt as both the creative force and lonely crusader for L.O.R. This was an exaggeration, perhaps customary in glossy magazines but scandalous to Langley engineers, who were always finicky about questions of scholarly attribution. Subsequently, Robert Gilruth was to become the leading proponent of an alternative interpretation of history, that Houbolt’s contribution really wasn’t that important—L.O.R. would have won on its engineering merits anyway. It is of course impossible to be sure what would have happened without Houbolt, but the text reflects our own reading of this history: Houbolt was not the originator of the L.O.R. concept (nor did he claim to be), but his advocacy was crucial, probably decisive, in leading to the adoption of L.O.R. There is a fascinating doctoral dissertation yet to be written on this episode, however.]

Houbolt was a Langley engineer who headed up the Rendezvous Panel, a group established in 1959 at Langley to support the planning for a space station. He had been working on the general subject of space rendezvous since 1957. In the course of these investigations, Houbolt too had begun to think about rendezvous in lunar orbit. At about the same time that Dolan and Brown were doing their work, Houbolt independently did what he called “back of the envelope” calculations that revealed large weight savings to be gained by use of a second spacecraft.

For Houbolt, what happened next was like a conversion experience. “Almost spontaneously,” he wrote later, “it became clear that lunar-orbit rendezvous offered a chain-reaction simplification on all back effects: development, testing, manufacturing, erection, countdown, flight operations,
etc.
All would be simplified. The thought struck my mind, ‘This is fantastic. If there is any idea we have to push, it is this one!’ I vowed to dedicate myself to the task.”

The scholarly John Houbolt became a crusader. Beginning in the summer of 1960, he wrote memoranda and letters, talked informally to anyone who would listen, and tenaciously tried to get across to NASA that a wonderfully simple way of getting to the moon was open to them, if only they would take a fresh look. Nobody paid much attention.

In December 1960, when a lunar landing was beginning to be taken seriously, Houbolt finally got his first chance to brief an important conference. Virtually everyone was there, including Glennan, Seamans, and von Braun. Houbolt and Brown put up a large chart and went through their arguments. When Houbolt finished presenting his estimates of weight savings, Max Faget spoke up from the audience, even blunter than usual. “His figures lie,” Faget said. “Houbolt doesn’t know what he’s talking about.” Even in a private bull session, Faget’s words would have been provocative. In an open meeting, in front of Houbolt’s peers and supervisors, they were a brutal thing for one Langley engineer to say to another.

When von Braun (who ultimately was converted to L.O.R.) was once asked about Faget’s remark, he shrugged and answered, “They [the figures] did lie. The critics in the early debate murdered Houbolt.” The crux of the problem, von Braun said, was whether the savings that L.O.R. promised were worth the price. “John Houbolt argued that if you leave part of your ship in orbit and don’t soft-land all of it on the moon and fly it out of the gravitational field of the moon again, you can save takeoff weight on earth,” von Braun said. “That’s pretty basic. But if the price you pay for that capability means that you have to have one extra crew compartment, pressurized, and two additional guidance systems, and the electrical power supply for all that gear, and you add up all this, will you still be on the plus side of your trade-off?”

In these early presentations, Houbolt and Brown were talking about three possible lunar modules, “plush,” “economy,” and “budget.” The budget model was a stripped-down, 2,500-pound version in which an astronaut descended on an open platform, and it attracted ridicule—the astronaut would descend “with a silk scarf around his neck,” it was said. Nobody in the Space Task Group seriously considered the stripped-down version. Faget argued that the weight of even the plush model was underestimated. Later, he enjoyed pointing out that the configuration that actually flew to the moon had a total weight (command module, lunar module, and service module combined) which approximated their initial calculations for direct ascent. It wasn’t really a fair comparison, as even Faget knew. The weight of the spacecraft-as-built would have grown as much from the spacecraft-as-designed if they had decided on the direct-ascent mode. But it was not obvious from the beginning that the weight savings of L.O.R. were as great as Houbolt claimed.

Apart from questions about the real magnitude of the weight savings, there was that rendezvous 240,000 miles from home to worry about. “We had never demonstrated a rendezvous,” George Low pointed out later. “L.O.R. involved doing a rendezvous a quarter of a million miles from home. It seemed like an extremely far-out thing to do.” Far-out, and dangerous. Low’s early task group thought it had to be more dangerous than either direct ascent or E.O.R. Direct ascent, if they had a big enough booster, would be the safest of all by virtue of being the simplest. And if direct ascent was not possible, then the rendezvous in earth orbit had to be safer. If the rendezvous failed in an E.O.R. mission, the astronauts in the manned spacecraft could fire their retro-rockets and return safely to earth while the unmanned segment continued to orbit. Or if for some reason the manned spacecraft was stranded in earth orbit, it was at least conceivable that a second spacecraft could be launched to rescue them. If a rendezvous failed in lunar orbit, the astronauts in the lunar lander were dead.

Furthermore, even in those days, NASA was already beginning to formulate the primal rule of manned space flight: Do not commit yourself any earlier than you absolutely have to. If there is any way to give yourself a way to back out, keep it. E.O.R. kept all sorts of options open longer than L.O.R. did. In earth orbit, the astronauts and ground controllers could check everything out while they still retained the option of canceling the mission and coming home. With L.O.R., some of the most critical maneuvers of the flight would have to be done after committing the spacecraft to a circumlunar trajectory. Still others would have to be performed after committing the spacecraft to a lunar orbit. There was no question about it: Maybe L.O.R. would save some weight, maybe it wouldn’t, but it was still too crazy for serious consideration.

For Houbolt and the other Langley people who were continuing to work on the L.O.R. problem, the criticism only goaded them on. From the end of 1960 through Kennedy’s speech in May of 1961, Houbolt and his colleagues prepared studies on lunar landers, landing gear, descent and ascent trajectories, and rendezvous maneuvers. The more they explored L.O.R., the more convinced they became that it was not just a faster way to get to the moon, it was also safer.

Just a week before Kennedy’s speech, Houbolt wrote a letter directly to Seamans, skipping over half a dozen bureaucratic layers in the process, pleading for a fair hearing for L.O.R. A few weeks later, when Seamans appointed Bruce Lundin from Lewis to investigate alternative modes for getting to the moon (“mode” is the NASA word for it, so that the whole lengthy process is now remembered as the “mode decision”), Seamans made sure Houbolt was on the committee.

The Lundin Committee, however, was another rejection for Houbolt. H e explained L.O.R. to the other members and got what was by now a standard response. “They’d say, ‘Oh, that’s good,’” Houbolt recalled, “and then the next day they’d laugh.” In its report, the Lundin Committee put L.O.R. at the bottom of its list along with lunar-surface rendezvous, a scheme whereby the astronauts would land on the moon with empty tanks and then do their own refueling from a fuel cache landed earlier. In Houbolt’s view, lunar-surface rendezvous was “the most harebrained idea I’d ever heard of.” That the committee put it in the same category as L.O.R. was degrading.

Next came the Heaton Committee, which had a charter to explore earth-orbit rendezvous. “I was in a strange position,” Houbolt recalled later, “because I was one of the staunchest believers in rendezvous in the country. I’m not against earth-orbit rendezvous; I am in favor of it.” It was just that Houbolt was so sure that L.O.R. was an even better way. “What upset me on the Heaton Committee,” Houbolt said, was that E.O.R. “was becoming a beast. The configurations [that the other members of the committee] were coming up with involved putting together five pieces of hardware. It was getting to be a great, big, long cigar.” Houbolt could hear engineers reading the Heaton Report and saying to themselves, “The guys on rendezvous are nuts like I always thought they were.” So Houbolt pressed on.

“That summer of 1961 was probably the busiest summer I’ve had in my life,” Houbolt said. “I was living half the time in Washington, half the time on the road, dashing back and forth.” In the early fall, he was asked to make a presentation on L.O.R. before the Golovin Committee, the group that was supposed to recommend the boosters to be chosen for Apollo. For the first time, a crack appeared in the united wall of opposition, as Nick Golovin (who, ironically, would later become a major antagonist to L.O.R.) saw some merit in Houbolt’s arguments. But it was only a crack, and Houbolt decided that they weren’t going to get anywhere until they put together such a thorough documentation of the argument for L.O.R. that it couldn’t be ignored. Houbolt, John Bird, and Arthur Vogeley put together a two-volume report describing the concept in full technical detail.

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