Apollo: The Race to the Moon (57 page)

Determining what had happened took M.I.T.’ s teams in Houston and Cambridge nearly the whole twenty-one hours that the Eagle was on the moon. Throughout the night and into the morning they burrowed deep into the computer system, searching for the mysterious something that had been eating up computer capacity during the descent. They ran sims of the software, sims of the hardware, and still they were unable to determine the source of the problem.

On the morning of July 21, George Silver, a heavyset man who looked more like a hard-hat construction worker than the software expert he was, walked into the Apollo Room at M.I.T.’s Instrumentation Lab to supervise the ascent phase. Ordinarily, Silver would have been in SPAN or the MER, but he was in the process of taking over the Systems Test Division at the Instrumentation Lab. When Silver arrived that morning, the team that had worked the descent was still there, unshaven and red-eyed, still working on the program alarm mystery. Something was stealing all the computer time, they told Silver.

Examining the printout, Silver was reminded of some simulations they had run on the computer on LM-1, the first lunar module, flown unmanned as part of Apollo 5 eighteen months earlier. At one point during the tests, they had turned off the simulator and “just let the lines hang open.” On that occasion, Silver had discovered that the computer kept trying to find angles and sines and cosines that matched whatever the signal might be, however meaningless. The situation with Apollo 11 looked much the same to him. He asked the weary M.I.T. team whether they had checked the rendezvous radar angles. Yes, they had, and the angles were moving pretty fast. Every time they moved even a little bit, Silver reminded them, that was a cycle steal—the computer was recalculating from scratch—and it could eat up as much as eighteen percent of the computer’s time. What might be causing the rendezvous radar to calculate angles so obsessively? They hadn’t by any chance had the rendezvous radar set to Auto, had they?

Steve Bales had stayed up long enough to watch the E.V.A. and then collapsed on a bunk in the controller’s lounge. When at 10:00 the next morning he took his place in the MOCR to work the ascent phase, he learned that SPAN still hadn’t received an explanation of the computer alarm anomaly. Bales was surprised—he wouldn’t have thought that any computer problem in the world could have stumped that team of people for that long, once they knew the symptoms. He was disturbed as well. In planning the flights, everyone had always assumed that the ascent would be more difficult than the descent. For a LEM going down, the surface of the moon was hard to miss. For a LEM going up, the C.S.M. was a small and elusive target. The prospect of lifting off with a computer that had been flighty and overburdened on the way down was not reassuring, and Bales was in no frame of mind for more dramatics. He had had enough excitement the preceding afternoon to last him for the rest of his career.

Bales was sitting at his Guidance console in the MOCR when the call came through, just thirty minutes before the scheduled liftoff: Tell the crew to turn the rendezvous radar switch to Manual, and they won’t have any more computer alarms. “I gotta believe you,” Bales said, and passed the word on to Glynn Lunney, who was Flight for the ascent. Lunney had to believe it as well. It was one of the last messages sent up to the crew before liftoff from the moon: Set the rendezvous radar switch to Manual.

L.O.R. had been considered so unrealistic in 1961 because of the maneuver that was now about to take place for the first time: a launch-to-rendezvous by a spacecraft 240,000 miles from home.

The first reason why that prospect had been so forbidding is that spacecraft cannot move sideways any great distance. They can move up, down, forward, or backward, but for practical purposes they are locked into the plane in which they have been launched—sideways movement against that momentum is extremely costly in propellants. Therefore the first constraint of space rendezvous is that the planes of the two rendezvousing spacecraft be virtually identical. This requires, obviously, great navigational precision during powered flight to orbit.

The next problem is timing. Because spacecraft carry limited propellants, it is not enough that the two spacecraft be in the same plane; they must also be reasonably close to each other when the second spacecraft reaches orbit, which means that the second spacecraft must be launched within a narrow time interval. If both spacecraft are launched precisely from the equator (of earth or moon) into an orbit directly above the equator, then the timing is fairly simple: Once during each orbit of the spacecraft in flight, the spacecraft on the ground has a brief period of time when it can launch and be in position to rendezvous. But if the plane of both spacecraft is anything except precisely equatorial, then the timing of launch is complicated by the fact that the earth and the moon rotate—the source of a phrase familiar to television viewers of launches at Cape Canaveral, the launch window. A spacecraft that can launch to rendezvous at time X cannot necessarily launch to rendezvous the next time the orbiting target spacecraft comes around. It might have to wait hours or even days, depending on the orbits involved. On a lunar mission, both spacecraft had tightly budgeted resources, and couldn’t afford to wait long if a launch window were missed.

Even after the second craft has lifted off at the right time into the right trajectory, the pair of rendezvousing spacecraft face a number of additional obstacles. If a spacecraft gets into orbit and finds itself in the identical plane as its target but just half a mile back, the pilot cannot simply step on the accelerator to catch up, because increasing his speed will increase the height of his orbit. The same principle holds true whether he is above, below, behind, or ahead of his target: He cannot point the spacecraft in the direction he wants to go and turn on the engine. Unless he is within a few feet of his target, the astronaut must rely on precise tracking data combined with sophisticated computer programs to tell him what direction to point, the duration of the burn, and what throttle setting to use.

These are just a few of the reasons why space rendezvous had seemed so daunting in 1961. Since then, rendezvous had been gradually demystified. The first rendezvous in history occurred in August 1965, on Gemini V. The plan had called for Gemini V to release a pod with a small radar transponder, let it drift away, and then find it again. But after the pod had been released, Gemini V developed a problem with its fuel cells, the rendezvous attempt was put on hold, and then the members of Ed Lineberry’s Rendezvous Section were told that the pod had drifted too far away to be found even if the fuel cell problem were to be solved. The bitterly disappointed controllers did the only sensible thing and retired to the Flintlock.* There, a few hours later, they got a call from Bill Tindall. The balky fuel cell was working again, and Bill had come up with a gangbusters idea. They didn’t need the pod. They could have the spacecraft rendezvous with a point in space. Everybody should get back to Building 30 right away. By that time, most of the members of the Rendezvous Section could barely navigate to the Flintlock parking lot, let alone find their way to Building 30. As the story is told, the surviving members of the Section who straggled back to Building 30 that night proved not only that rendezvous could be done, but that the controllers didn’t even need to be sober to do it.

[* The Rendezvous Section was notable for including a woman. Her name was Cathy Osgood—the first woman we have mentioned whose role was something other than wife or secretary. There were just a handful of others (Rita Rapp, who ran the nutritional program for the astronauts, was apparently the highest ranking). Women engineers were exceedingly rare either in NASA or on the contractors’ staffs.]

Four months later, in December 1965, Gemini VI rendezvoused not with a phantom, but with another manned spacecraft, Gemini VII. This was followed by an unbroken sequence of successful rendezvous in Gemini VIII, IX, X, XI, and XII. The Gemini flights performed co-elliptical rendezvous and equi-period rendezvous; they rendezvoused from above and they rendezvoused on the first apogee. These were followed by the successful rendezvous of the LEM and C.S.M. in earth orbit on Apollo 9, and in lunar orbit on Apollo 10.

Thus on July 21, 1969, rendezvous itself was not the fearsome thing it had seemed at the beginning of the space program. The main concern now was that the ascent engine start. To that end, the ascent engine on the LEM had been made as simple as a rocket engine could be, with only two moving parts in the entire assembly. It had a magnificently reliable record in the ground tests.

Nonetheless, the first liftoff from the moon was a tense moment for everyone, just as Eight’s entry into the first lunar orbit had been. For Mike Collins, circling the moon alone in Columbia, the lunar liftoff was the most nerve-wracking moment in his long flying career: During the six months since he had been selected to be the command module pilot, his secret terror had been that he might have to come back to earth alone. For Glynn Lunney, waiting at the flight director’s console, this moment was an odd mix of emotions. As at liftoff for any flight, he felt tense (“trying to hold my breath for eight minutes”). But in an odd way, the ascent from the moon was not as draining on the flight director as a launch from earth or any other phase of flight where there was a choice of aborting or going ahead. With the lunar ascent, “there were no decisions to make, so in that sense it was easy. You just say, ‘Well, let’s light this sumbitch and it better work.’”

It did. After a stay of twenty-one hours, Eagle’s guillotines slashed the connections linking the descent and ascent stages, the ascent engine went instantly from a cold start to full power, the computer did all its work without lighting up any master alarms, and within three hours the Eagle was keeping station with Columbia, ready for an uneventful docking.

At dawn on Thursday, July 24, 1969, Apollo 11 splashed down in the South Pacific close to the Navy aircraft carrier Hornet. In the MOCR, which had passed control to the recovery team in the adjacent room when the parachutes deployed, a television image of Columbia bobbing in the water was projected up on the right-hand screen. The MOCR was jammed with people, waving small flags and smoking the traditional splashdown cigars. The large center screen, which for the past eight days had been showing trajectories to the moon and lunar-orbital tracks, went black. In a moment, it lit again, with these words:

I believe that this nation should commit itself to achieving the goal,

before this decade is out, of landing a man on the moon and returning him safely to earth.

—John F. Kennedy to Congress, May 1961

Since Columbia had splashed down, the right-hand screen had been displaying the mission patch of Apollo 11. As the helicopters lifted Eleven’s crew to safety, these words appeared above it:

Task accomplished. July 1969.

Chapter 26. “I think we need to do a little more all-weather testing”

Walter Kapryan, “Kappy,” looked unhappily through the windows of the Firing Room at the skies over the Cape. It was Friday, November 14, 1969, and the launch of Apollo 12 was scheduled for 11:22 that morning. Kapryan, a Langley man and an early member of the Space Task Group, was directing his first launch since taking over the Launch Operations Directorate from Rocco Petrone. Petrone, who had moved into Sam Phillips’s job as Apollo program manager when Phillips returned to the Air Force, had left Kapryan a daunting record to live up to. Petrone had launched every Apollo flight thus far at precisely the planned second—two Saturn IBs and six Saturn Vs: eight flawless launch schedules in a row.

The weather outside was iffy. Yesterday, it had been plainly unacceptable, with thunderstorms passing through the Cape all day. The skies had cleared during the night and it had looked as if the launch was safe, but now the morning had brought more clouds and intermittent rain. The pressing question was whether the current conditions fell within the weather rules for a launch.

Kapryan kept planes and weather balloons at varying altitudes above the Cape throughout the morning. He wasn’t worried about the rain—short of torrential downpours, the Saturn V wasn’t affected by rain—but either high winds or lightning would scrub the launch. All morning, however, the word coming back to the Firing Room was the same: Winds were light at all altitudes. The Sweeney meters they used for measuring lightning potential showed no problem. The countdown continued.

By 11:00, Kapryan was still edgy. They were not in violation of the weather rules, but the cloud cover was at less than a thousand feet and the rain was getting worse. It just didn’t feel like a good day to launch a Saturn V. But none of Kapryan’s options was without risk. The Saturn was fully fueled and (after a quick fix of a minor fuel cell problem) working perfectly. The spacecraft was working perfectly. The astronauts—an all-Navy crew consisting of Pete Conrad, Alan Bean, and Dick Gordon—were already on board. To offload the propellants, reload them, and recycle the countdown was a major job that would introduce a variety of hazards. The spacecraft and launch vehicle were never going to be more ready than they were now. The next time, there might be a small, not-quite-inviolation problem with the vehicle that would worry Kapryan a lot more than the weather was worrying him today.

To increase the pressure, the President of the United States, Richard M. Nixon, was sitting in the small V.I.P. room, a triangular glass enclosure that jutted out over the Firing Room like the prow of a ship. Kapryan knew he couldn’t let Nixon’s presence affect his decision, but having the President watching from up there, waiting to see the advertised launch, didn’t make Kapryan’s job any easier. Kapryan silently asked himself, as he would in the last minutes before every launch he directed, What am I doing up here? Isn’t there a better way to make a living?

At the rows of consoles below him, the countdown was as smooth as he could wish. Kapryan decided: As long as the rain didn’t get worse and the wind didn’t rise and there was no lightning, the rules said Launch, and that’s what he was going to do.