As soon as the PC+2 burn was over, Brand expected Kranz to give him the go-ahead to read off the procedures for powering down the spacecraft for the long coast back to earth. Looseleaf notebooks giving the procedures were spread out on Brand’s console, and he was anxious to get on with them, because he realized how tired the astronauts were, and wanted to get them to bed. CAPCOMs sometimes have to represent the crew’s interests on the ground. The go-ahead for the power-down never came, and when Brand turned around to find out why, he saw a number of men standing around Kranz’s console. Kranz was in the middle of what he later called “a long and loud debate” between the TELMUs, on one hand, who were anxious to proceed with the power-down immediately, and a group of design engineers, on the other, who were insisting that a good thermal roll be set up right away; the spacecraft’s attitude in relation to the sun had been so erratic for about a day, they argued, that some part of the craft was likely to overheat and break down. Having the astronauts roll the spacecraft manually every hour had not proved effective, and the design engineers were hoping to set up an automatic roll, monitored by computer. The TELMUs had powerful allies in members of the astronaut corps, for, like Brand, they all wanted to get the spacecraft powered down as soon as possible, to let the crew have some rest. Donald K. Slayton, who, as Director of Flight Crew Operations, was the unofficial chief astronaut, was telling Kranz that it would take a good two hours to set up a roll, and the astronauts in the spacecraft had had almost no sleep for the better part of two days. The TELMUs were saying that keeping the LM powered up for another two hours would knock their power profile out the window, and that that was nothing compared to what would happen to it if they had to keep the guidance system powered up to monitor the roll. Kranz listened, and then, in the NASA tradition of the top man’s making the decision, announced that they would set up the roll anyway—the astronauts, he reasoned, would be better off losing a little more sleep than risking any more breakdowns. They would not, however, keep the guidance equipment powered up all the way back to earth.
Brand put aside the power-down checklist and began reading up the procedures for the roll instead. The LM’s guidance system had never been designed to maintain a roll, and doing so was particularly difficult with the two other modules attached. Each time the astronauts got the spacecraft rolling, it developed a wobble, and the wobble worsened until there was no roll left—the spacecraft was like a top at the end of its spin. While the astronauts continued to wrestle with the roll, the FIDO was plotting vectors to get some idea of how accurately the spacecraft had been placed on its new trajectory. David Reed, the Lead FIDO, was worried because there appeared to be an unexplained error in the trajectory. The spacecraft was about one degree from where it ought to be. For a minute he thought he had the answer—he heard Swigert boast that he had been the first Command Module Pilot ever to witness a lunar module rocket burn from inside the LM. When Reed checked with the Control, the two agreed that Swigert’s having been out of place was enough to throw the spacecraft off course, as if it were a small boat. Neither Reed nor the Control was satisfied with this explanation, though, because the aberration in the trajectory was a large one, and it was getting worse. Something in the spacecraft had to be venting, but Reed couldn’t think what.
The astronauts were not told that night about the increasing error in their trajectory. While Lovell kept trying to work the wobble out, Haise began powering down parts of the lunar module. What the TELMUs couldn’t win directly, they won by persistence and stealth: they were continually getting Brand to read up small lists of items to turn off. For the two-and-a-half-day coast back to earth, the LM would be almost as inert as the command module. About the only things to be left running would be the radio transmitters and the life-support system.
After an hour and a half, Lovell felt he had set up as good a roll as he could get. Accordingly, when Brand was transmitting some more suggestions from Duke, in the simulator, one of the astronauts in the spacecraft interrupted, “Hey, we’ve gone a hell of a long time without any sleep,” and another voice put in, “I didn’t get hardly any sleep last night at all.” At about ten-thirty—some twenty-four hours after the accident—Brand told the astronauts that they could begin to power themselves down. This was easier said than done, for the astronauts had built up a good deal of nervous energy. They still hadn’t gone to sleep an hour later, and Brand then radioed up instructions from Slayton that they stop fiddling around and get to bed. Swigert, however, who was particularly keyed up, ran through a recapitulation of his impressions of the accident for Brand.
Rounding the moon had given the astronauts’ spirits something of a lift, but now that they were on the quarter-million-mile straightaway back to earth, Swigert was growing increasingly apprehensive. As command-module pilot, reëntry would be up to him. He told Brand he was worried about the command module’s fitness; in particular, he was concerned about Main Bus B, where the failure in the electrical system had first become apparent. During reëntry, along with Main Bus A, it would be providing power drawn from the three reëntry batteries—assuming the bus itself hadn’t been damaged by the accident. “You think Main Bus B is good, don’t you?” Swigert asked anxiously.
Brand answered, “That’s affirm. We think it is, but we want to check it out anyway. We think you guys are in great shape all the way around. Why don’t you quit worrying and go to sleep?”
“Well, I think we just might do that. Or part of us will,” a voice said from the spacecraft.
BACK
GENERALLY SPEAKING, space-flights are less satisfying to the people who follow them on television than the adventures of earth-bound explorers have usually been to those who have read about them in books. For one thing, technology seems to impinge too heavily on the televised space travels; what was once called a spaceship, to give a small example, has become a module. However, technology notwithstanding, the men who ply between the earth and the heavens are not doing anything much different from what was done by the explorers who merely used the heavens to steer by. The Apollo 13 astronauts were now in every bit as understandable and distressing a predicament as any seamen aboard a leaky vessel in danger of foundering. This was readily grasped by the estimated third of the world’s population who were following Apollo 13—probably more than had followed any other spaceflight. There was a sort of worldwide shudder of horror, for if these men died they could do so in a way no men ever had before: they could be the first never to return to the dust of this planet. Newspapers in many countries published cartoons representing the world with a pair of hands; in some cases the hands were reaching out for the astronauts, and in others they were simply clasped in prayer.
Despite similarities with earthbound crises, getting the astronauts back would obviously require a vaster cerebral effort than any conventional rescue operation. After the PC+2 burn, Kranz removed his White Team from the regular cycle of shifts—or, as he put it, he “took it off the line,” the way astronauts might set aside a battery that was needed for some special purpose—so that its members could devote themselves entirely to this effort. While the three other teams were handling the relatively routine coast back toward the earth, the White Team would be writing a new reëntry checklist. A checklist for a spaceflight can be as thick as a telephone book and take three months to prepare; now the White Team had to write one in less than three days, and that span of time would shrink by half a day before they actually got down to it, for Kranz wanted his team to get some sleep before they set to work. According to Swigert, the astronauts could never have got back to earth without the White Team’s checklist. On that trip back, a number of things would have to be done that had never been done before. In the last hours of the flight, the astronauts would have to leave the lunar module and find some way to power up the command module, the only part of the spacecraft that had a heat shield. A power-up of a dead command module had never even been simulated on the ground, let alone attempted in space, and there were many questions. Wo
uld the command module’s delicate electronic systems work after more than three days of cold? For that matter, would its three reëntry batteries, which would be supplying its power when it was flying alone, still work after the long chill, or would they be weak and useless, like a car battery on a cold winter morning? Besides these problems, there would be unprecedented difficulties in getting rid of the two other modules just before reëntry.
The necessity for all these new and untried maneuvers meant that the flight controllers couldn’t borrow much from the checklists of previous missions—something they normally did—and this inability made them grateful for the extra day the slower PC+2 burn had given them. Doing three months’ work in under as many days meant they had to take shortcuts they had never thought possible. Afterward, David Reed, the Lead FIDO, said, “When you take a lot of time, you get the most conservative consensus. But here we shaved off the conservatism to give some fast decisions, and we stuck with them. We found out what we could do when the chips were down. Often, the only Simulators we had were our minds,—and damn if they didn’t work!”
Early Wednesday morning, Haise was on watch in the lunar module while the others slept in the command module. The temperature in the LM was about fifty-five degrees and falling, for the TELMUs had decided that, during the long coast back to earth, the LM could draw only eleven amperes from its batteries. That way, there would be more electricity to transfer to the command module at the end of the flight.
Jack Lousma, who was back as CAPCOM, did his best to give Haise a little company. Haise told him he could now tell that the spacecraft was definitely moving away from the moon, because, for the first time, he was able to get the entire moon in the field of vision of the LM’s monocular, or hand-held telescope. The craft was then over twenty thousand miles away from the moon. Lousma did his best to keep Haise’s spirits up—sometimes the CAPCOM had to act as a fourth member of the crew. When the spacecraft wobbled and Haise had to scramble to switch omni antennas, Lousma said soothingly that everyone in Mission Control was one hundred per cent optimistic, and he added, “It looks like we’re on the up side of the whole thing now.” The up side had its down moments, however. Once, for instance, Haise remarked that he saw a chunk of silvery metal, about four inches square, tumbling around outside the window. Presumably, it was part of the spacecraft’s ruptured oxygen tank. Haise was looking out because, with the guidance platform turned off, the only way he could check on the roll was to time the alternate reappearance at a window of the earth and the moon. From time to time, he would say to Lousma, “O.K., the earth went by there,” or “There goes the moon.” There was a reticle—a grid of hairlines for measuring positions—printed on the glass, and every time the earth or the moon went by, Haise would look to see if it was in the right spot. It never was; at each pass the moon seemed to be a bit higher and the earth a bit lower, and that meant that the spacecraft was still wobbling. It seemed as if something was venting.
At three Wednesday morning, Lousma heard Lovell’s voice on the radio. “Gee whizz,” Lousma said, “you got up kind of early, didn’t you?” Lovell replied that it was cold upstairs in the command module—that the temperature was somewhere in the forties. This was the first indication that the temperature in the command module, which had dropped irretrievably when Lovell had pulled the blinds, would keep the astronauts from sleeping. Their clothing, designed with the spacecraft’s normally conditioned air in mind, was of a flimsy material called Beta cloth, and their sleeping bags were merely thin sheets of fabric designed to keep them from floating around, and were, in fact, perforated for ventilation. It was suggested by the controllers that the astronauts put on their space suits, but they declined, on the ground that the suits would make them too clumsy to handle the spacecraft efficiently. There were some blankets stored near the floor of the command module in an emergency pack to be used in case the astronauts weren’t rescued after splashdown and had to head for shore themselves; but the astronauts didn’t open the emergency pack because it was so tightly put together that they could never have packed it up again after removing the blankets. If they had opened it, the spacecraft would have been awash in flashlights, tinned foods—even a rubber boat.
At ten-thirty on Wednesday morning, a yellow caution light flashed inside the LM to indicate that the level of carbon dioxide in the spacecraft’s atmosphere had built up to the point where something had to be done about it. The Crew Systems Engineers in Houston who had been working on this problem for a couple of days had finally come up with a way of adapting the command-module canisters for use in the LM: There was a hose in the LM meant for sucking air out of space suits, should the astronauts be wearing them, and this could be used to suck cabin air through the canister—provided an airtight connection between hose and canister could be devised. The Crew Systems Engineers had found that they could make the airtight connection out of one of the plastic bags used for storing part of the astronauts’ moon-walk garb. The bag could be put over the canister in such a way that the canister’s open mesh bottom was outside; then a hole could be cut through the other end of the bag for the hose; and finally, the whole apparatus could be sealed with tape. A major stumbling block had been how to prevent the plastic bag from collapsing with the suction. After experimenting an entire night, the Crew Systems Engineers had solved the problem by holding the bag away from the mesh with one of the astronauts’ plastic checklist cards.
The astronauts were very curious about the contraption, for the previous day Vance Brand had given Lovell something of a preview of it by telling him that making it would be like putting together a model airplane, but that when the thing was finished it would look more like an R.F.D. mailbox. During the night, Haise had got together several of the items needed for the project—plastic bags, a roll of tape, a checklist card—but now Haise had gone to bed. Lovell and Swigert were up. Down in the Control Room, the Black Team had just taken over from the Maroon Team, and Joseph Kerwin, who had relieved Lousma at the CAPCOM’s console, had got them started on the mailbox. It hadn’t been easy to explain over the radio how to build something that no one had ever seen before. “Now, then, we want you to take the tape and cut off two pieces about three feet long, or a good arm’s length,” Kerwin had begun. Earlier, the Crew Systems Engineers had pondered over the best way to say “thirty inches.” “Two or three feet?” “An arm’s length?” They had decided to say both. (Wording would prove to be a problem with the entry checklist, too.) Now, when the caution light went on, Lovell turned on the suction. Air from the cabin was drawn through the canister and scrubbed air was vented back again, and in a short time the carbon-dioxide level was back to normal.
The planning for the reëntry checklist got seriously under way at a meeting at about one o’clock Wednesday afternoon, when splashdown—set for around noon Friday—was less than two days away. The meeting had been put off until one in the afternoon in order to give the White Team a good rest following the PC+2 burn the night before. However, because this was the fifteenth of April, several of the flight controllers had spent some of the intervening hours doing their income taxes, which they had left until the last minute because everyone had expected the flight to be a smooth one. The White Team met once again in the unused Staff Support Room on the second floor of the Operations Wing, beneath the big room where the controllers worked and above a computer room on the ground floor. Some of the flight controllers present referred to themselves as the Tiger Team, because the White Team had been augmented by a number of outside engineers, and, in addition, a number of changes had been made in the team assignments, so that the White Team would include most of the Lead controllers. These were the Lead FIDO, David Reed; the Lead GUIDO, Kenneth Russell; the Lead RETRO, Charles Deiterich; the Lead EECOM, John Aaron; the Lead GNC, Buck Willoughby; the Lead TELMU, William Peters; and the Lead CONTROL, Harold Loden.
What the Tiger Team was planning was the last six hours or so of the flight—the crucial period when the crippled spacecraft
had to be made ready for the plunge through the atmosphere. Kranz, the Flight Director, standing at the front of the room, briefly outlined what he thought were the most important points: The controllers would have to be completely accurate, because the spacecraft would be less flexible and therefore less tolerant of error than ever before. They would have to develop procedures in such a way as to let the LM do most of the work. There might be many ways to do the job but only one that was best, and that was the way that would be easiest on the consumables and easiest on the astronauts. The talk was over quickly, for Kranz’s words tended to be terse, like those of the captain of a ship caught in a squall.
Kranz felt that the key to the problem was to conserve the command module’s reëntry batteries as long as possible by having the lunar module supply all the electricity for the initial powering up and warming up of the command module; only in that way was there a chance that the reëntry batteries would last through the critical period between the jettisoning of the LM and the splashdown—the period when the command module would be flying alone. Normally, the three reëntry batteries were expected to provide power for about forty-five minutes, but now it was a question of doing so for several hours. Moreover, there were only two and a half reëntry batteries this time, because half of one had been used up after the accident, and, all told, they could provide only ninety-six ampere-hours of electricity. (One amp-hour of electricity, on the spacecraft’s twenty-eight volt current, would keep a forty-watt bulb burning for one hour.) Obviously, then, the more the LM could do for the command module ahead of time, the better. Since everything depended on the transfer of power from the LM to the command module, and since such a transfer had never been tried before, as soon as he had adjourned the meeting Kranz beckoned to three engineers. One, from the Grumman Aerospace Corporation, was a chief designer of the LM; another, from the North American Rockwell Corporation, was a chief designer of the command module; and the third was the Lead EECOM, John Aaron, who would be in charge of the power-up. Kranz wanted to get these men together because they had most of the necessary information in their heads: Aaron knew what had to be powered up, the North American man knew how much power it would take, and the Grumman man knew how to deliver the power from the LM. Later, some of the flight controllers said Apollo 13 was “an EECOM’s mission” equally as much as a RETRO’s. Aaron, a tall, ruddy-faced twenty-seven-year-old graduate of Southwestern State College, was a veteran of many emergencies—he had been the man who had made the decision to go ahead with the Apollo 12 mission after the spacecraft had been hit by lightning. He said later that the members of the Tiger Team were all perfectly well aware of how little time they had before the astronauts smacked into the atmosphere but that nobody in the room seemed to have a clear idea of where to begin. People seemed to be wandering aimlessly about. “Suddenly I realized that it all had to begin with me,” Aaron recalled. Since he knew he couldn’t formulate a coherent plan with so large a group, he collected four or five other flight controllers and took them, along with the men from Grumman and North American, over to a quiet corner. Kranz said later that there were only a few things he would do differently if a similar crisis arose again, but one would be to pack off small groups of engineers to other rooms instead of having them all milling around in the same place.
Thirteen: The Apollo Flight That Failed Page 8