Apollo: The Race to the Moon (52 page)

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Authors: Charles Murray,Catherine Bly Cox

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

BOOK: Apollo: The Race to the Moon
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Chapter 24. “We … we’re go on that, Flight”

Dramatic as Apollo 8 had been, and as novel as the lunar journey had made it seem, the crew had stayed in the command module and performed the kind of maneuvers astronauts had been performing since the first orbital flight in 1962. As 1969 began and preparations for Apollo 9 drew to completion, that was about to change. Beginning with Nine, a brand-new spacecraft was going to be flown, one that functioned very differently from the command module—and, for that matter, differently from any machine that man had ever flown before.

1

The lunar module was a spidery, flimsy contraption. Since the days when Caldwell Johnson and Owen Maynard had drawn designs for the landing gear based on the assumption that the moon would be just like Arizona, the Grumman engineers working on the lunar module had taken the craft through a series of incarnations.

Because it functioned exclusively in the vacuum of space, encountering no air resistance, the lunar module could “be any shape it wanted to be,” as one of the early designers put it. “The realization of this was slow to come for some of us, slow to come that it didn’t have to be round-edged and smooth, that it could be square. It could have corners on it. Things could stick out at odd angles, it didn’t make any difference.” It was disorienting. “Suddenly we were in a very, very free-form world of engineering. There wasn’t any precedent. And we developed a shape that at first looked ridiculous, and looked more and more ridiculous as we worked on it.”

It wasn’t just the shape that was different; the materials were also different. The moon’s gravity is only one-sixth of earth’s, and the stresses that the LEM would have to endure were proportionately smaller. The result was that the LEM’s materials were so light they felt like paper to the workers at the Grumman plant. Because they were so light and flimsy, fittings often couldn’t be stamped out without creating stress lines. Much of the LEM had to be made by hand, with the Grumman technicians taking a block of metal and milling it until it fit the blueprint.

To complicate matters, the propellants for the LEM were so incredibly volatile, one technician remembered, that he could dip a stick into the oxidizer and flick a few drops onto snow on the ground—and the snow would catch fire. The internal pressure in some of the tanks was in the neighborhood of 6,000 pounds per square inch. This combination of lightweight materials, caustic gases, and high pressures was particularly dangerous. One day, a technician at White Sands working with a fully fueled test article was filling out a report and absentmindedly clicked the end of his ballpoint pen on a fuel tank. The pen exerted just enough extra pressure on the tank to open a pinprick leak. Eventually, or so the story goes, they found the pen embedded in a fence post, along with a nub of finger bone. The wire-thin stream of propellant had sliced through flesh and bone as neatly as a scalpel.

Because it was called “the bug” and because the command module was thought of as the mother craft, people tended to think of the LEM as being much smaller than the command module. In reality, it was twenty-three feet high compared to less than eleven for the command module, and with a larger internal volume as well.* It consisted of two separable parts. In the upper portion, along with the ascent engine and its fuel tanks, was the cockpit where the astronauts stood while they descended to and ascended from the lunar surface. They also used this area to eat, sleep, and change into their lunar-surface suits and backpacks. The descent engine, its tanks, the landing gear, and the storage areas for the experimental apparatus (and in later missions the Lunar Rover used to explore the lunar surface) were all in the lower portion. On liftoff from the moon, pyrotechnics and a guillotine apparatus separated the two portions of the LEM. The ascent stage returned to the command module; the lower portion remained on the lunar surface. After the two spacecraft had rendezvoused and all the lunar samples had been moved from the lunar module to the command module, the ascent stage was set adrift, and only the C.S.M. left lunar orbit for the trip home. The lunar module was thus a formidably complex vehicle, a self-contained system designed to perform multiple functions under unique, never-before-experienced circumstances. Apollo 9 was the first of the missions to attempt to operate it.

[* All spacecraft until the shuttle (discounting Skylab, which was not a spacecraft) were claustrophobically small. The Apollo command module, spacious by comparison with Mercury and Gemini, had three men lying shoulder to shoulder, with the control panels only a few feet from their faces, for up to fourteen days. The much-talked-about “lower-bay area,” which the press sometimes described as if the astronauts had the equivalent of a little room to go to, provided enough extra space for the astronauts to move about—not much, but a little—during the course of the flight. In the Mercury and Gemini capsules, they could hardly move at all.]

Apollo 9 was commanded by Jim McDivitt, the man who many within the Apollo Program thought should have commanded the first lunar landing. Jim McDivitt was that good at everything—so good, that when Low eventually left ASPO, McDivitt was chosen to replace him. But Deke Slayton, who ran Flight Crew Operations, was unalterably committed to a rotation system for assigning crews to missions. Anything else, he thought, was an insult to the astronauts and destructive of morale. Others in ASPO and the Flight Operations felt just as strongly that some astronauts were more equal than others, and it was foolish not to pick the very best of the best for the first lunar landing. They had managed to set up a roster of missions so that the rotation was likely to turn up McDivitt or Frank Borman, another especially highly regarded astronaut, for that plum assignment. But first the fire, and then the insertion of C-prime into the schedule, had thrown off those calculations, and Slayton had rejected suggestions that the crew rosters be revised.

And so the luck of the rotation had instead left Jim McDivitt with Apollo 9. This was too bad for him, but it was not such a bad thing to have one of the best astronauts commanding Nine. In the judgment of people around MSC, Apollo 9 was, with the exception of the first landing itself, the most difficult of the Apollo flights. It involved not only the first test of the LEM, with all the hazards and difficulties associated with a maiden flight and a rendezvous, but also an extra-vehicular activity (E.V.A.) by astronaut Rusty Schweikert to test the backpack that would be used for exploration of the lunar surface. Such E.V.A.s, known as space walks to the media, were one of the few activities in manned space flight that were even more dangerous than they looked. On top of all this, Nine would be flown in a low earth orbit, which, for technical reasons involving both communications and navigation, was more difficult than trying to carry out the same activities on a real lunar mission. Apollo 9, the D Mission in Owen Maynard’s alphabet schedule, was known within the program as the connoisseur’s mission.

Demanding, dangerous, crucial to the success of the program, and also perhaps the most anonymous of the Apollo missions, Apollo 9 was launched on March 3, 1969, carrying McDivitt, Schweikert, and David Scott. The mission lasted ten days, during which the LEM separated from the command module, fired both its descent and its ascent engines in a variety of modes, and performed without a hitch. Outside NASA, the media and the public paid little attention. Within NASA, Apollo management penciled in the G Mission for a July launch.

2

The F Mission came next, a lunar flight like Apollo 8 but with a LEM that would be manned and flown to within 47,000 feet of the lunar surface. Forty-seven thousand feet was a natural cutoff point, the altitude at which the LEM would fire its descent engine for the landing, the maximum altitude at which its landing radar could be tested, and the minimum altitude at which the C.S.M. could come to the assistance of the LEM in case of need. But 47,000 feet was so close to the promised land. Many in the space program—George Mueller among them—thought it foolish to go all the way to the moon, take all the risks associated with the journey, and then stop nine miles short of the surface. If everything looked good, why not be prepared to take advantage of success and go all the way down?

Owen Maynard hadn’t included an F Mission in his original schedule. As far as the hardware was concerned, there was no need for it. D and E—or, as things worked out, C-prime and D—had exercised all the systems under all the conditions they would have to face for a landing. But Maynard was part of ASPO. Over in the Flight Operations Directorate, Rod Rose and Carl Huss had been discussing the same problem and were insistent on having an F Mission. “We said that operationally we’d like to have everything else S.O.P. from beginning to end so that [the astronauts] had a storehouse of experience and knowledge,” Rose remembered, and there was a good reason for it. Learning to take the LEM from the command module down to 47,000 feet was a big job in itself, and Rose and Huss felt that the less that was new when the time finally came for the first landing, the better. So despite some spirited arguments within NASA itself, Apollo 10 with a crew of Tom Stafford, Gene Cernan, and John Young blasted off on May 18, 1969. Three days later, Stafford and Cernan undocked the LEM they had named Snoopy from the command module and descended toward the lunar surface.

The most hair-raising moment in Apollo 10 occurred then, with the LEM far from the command module, circling low over the moon, as the crew tried to separate from the LEM’s descent stage. One of the two astronauts had accidentally mis-set a switch, causing the abort guidance system to begin searching for the command module, which threw the LEM into wild gyrations. “Sonofabitch!” Cernan yelled, disrupting NASA’s unremitting effort to make the astronauts come across as squeaky clean in every way.* Stafford took over manual control of the LEM before the guidance system locked altogether, and managed to bring it under control. The test of the LEM in lunar orbit ended uneventfully, and Ten was another in NASA’s growing string of successes.

[* Cernan caused NASA’s public relations officials to blanch only momentarily. Other astronauts caused months of fretting. One, a cheerfully uninhibited fellow who used four-letter words as grace notes to his everyday conversation, was a special project. Look, they finally told him, hum instead of talking. (Another version of the story is that NASA actually sent him to a psychologist, who hypnotized him and left him with the posthypnotic suggestion: Hum.) That’s why, in the tapes of his mission, one Apollo astronaut can be heard going “dum-te-dum-te-dum-te-dum” as he bounces across the lunar surface.]

All of the intermediate steps had been taken. More than half of 1969 remained. To fulfill the commitment that John Kennedy had made eight years earlier, the one remaining task left to NASA was an actual lunar landing.

3

With the manned missions coming at the rate of one every two or three months, it was not feasible for a flight controller to work every mission. Each mission had three flight directors, with a fourth available to fill in occasional gaps. One flight director was designated the lead flight director for each mission, responsible for its overall supervision. The mission everyone wanted to work was, of course, G. And within the G Mission, the shift everyone wanted to work was the lunar descent.

Cliff Charlesworth was the lead flight director for the G Mission. He did not hesitate in picking the flight director for the lunar descent. It had to be Kranz. Kranz had been Flight on Apollo 5, the first unmanned test of the LEM. He had worked the LEM maneuvers on Apollo 9, the first manned test of the LEM. No one else had nearly the experience with the lunar module that Kranz had, plus something else. “Gene was the guy you wanted on the headset when there was trouble,” Charlesworth said later. “When the term ‘flight controller’ is used, the first person I think of is Kranz.”

That decision made, Charlesworth asked himself who had the most experience with rendezvous. The answer was Lunney, so Lunney got the lunar ascent. That left the launch phase and the lunar-surface activities for Charlesworth. Milt Windler, one of the three newest flight directors, would round out the team.

The experience with the LEM that Kranz’s White Team brought to the G Mission from Nine and Ten was limited to the LEM systems and how the machine flew. Accomplishing the actual landing posed new problems. The flight profile from Apollo 10’s 47,000 feet on down was tricky even if nothing went wrong.

The first key point was P.D.I., powered descent initiation, when the crew had to fire the lunar module’s descent propulsion engine (DPS, “dips,”). After that moment, the command module was useless as a rescue vehicle. If something did go wrong, no matter what the failure might be, the astronauts would have to use the LEM to get back up again for a rendezvous.

During the first part of the burn, the descent engine pushed forward against the LEM’s momentum, to slow the orbiting spacecraft, keeping the LEM in a legs-forward position almost parallel to the moon’s surface. During this phase, the crew would be able to look down at the lunar surface, but they would not be able to see where they were going. At about four minutes into the burn, the LEM would rotate so that the critical radar systems would now be looking down, acquiring the data that would guide the spacecraft to its planned landing site. At approximately six and a half minutes into the burn, the crew would throttle DPS back to about 55 percent power. At eight minutes, now only 7,500 feet from the surface, the LEM would pitch forward so that it came nearly to the vertical, enabling the crew to see out their windows toward the landing site. Then it would be time for the landing itself.

The LEM was designed to fly like a helicopter with a rocket engine instead of a rotor. Like a helicopter, the LEM was not easy to fly. On the ground, the crew had three different ways to practice. One was in the simulators at M.S.C. and the Cape, which didn’t fly but could rotate and tilt and show lunar views out their windows. The second was an ingeniously constructed tower facility at Langley, where the crew could practice the final seventy feet of the descent in a simulator suspended from the top of the tower in such a way as to duplicate one-sixth earth gravity. Finally, there was the “flying bedstead,” a free-flying machine that had given everyone scares for the last year. First Armstrong and then another test pilot had been forced to bail out when the machine crashed. It had been grounded for many months, and only because Armstrong insisted was he permitted to resume using it for practice in the spring of 1969. To some degree, design faults made the flying bedstead liable to crash, but there was more to it than that: A machine that truly mimicked the task of flying a lunar module was going to be hard to fly.

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