Kraft wanted to get the advice of the Lead RETRO and the Lead FIDO, both of whom were then on duty with the Gold Team. Deiterich, who had been up all night, arrived at the glassed-in gallery followed by David Reed, the Lead FIDO—a tall man of twenty-eight with light-brown hair, a graduate of the University of Wyoming, who joined NASA in 1964. Reed was more rested, for he had been at home in bed at the time of the accident, and when he turned on his television set and observed Deiterich and several other dynamics officers already in the Trench he had sensibly taken three aspirins and gone back to bed, on the theory that he would be of more use in the morning if he got some sleep. He had had a restless night anyway, and had come in to work at four o’clock in the morning.
Reed and Deiterich, who would be the ones to work out whatever trajectory the meeting settled on, were both opposed to any burn that required jettisoning the service module. Reed pointed out that if they retained the service module and did the slower burn, they would still have the option later, if anything else went wrong, of jettisoning the service module and making a faster burn. NASA engineers tend to favor any alternative that “keeps the options open.” Kraft, who was also in favor of retaining the service module and doing the slower burn, summed up the case for this alternative strongly, and Dr. Gilruth, who had said little during the meeting, nodded assent. The men who had to plan how to bring the crippled spacecraft back through the atmosphere were grateful for the extra twenty-four hours that the slower burn gave them.
Deiterich and Reed went back to their consoles, which were side by side in the Trench. Reed’s had a single orange light that flickered constantly, showing that telemetry was being loaded into the computers downstairs, but Deiterich’s console had no lights whatever. It had two television screens and six clocks. Under the glareproof glass covering the console’s desk there was a map of the earth, centered on the Pacific—the target Deiterich was aiming for. As he began planning the PC+2 burn, he also began to consider some of the problems that would come up at reëntry. The astronauts, back in the command module by then, would have to jettison both the service module and the lunar module before the spacecraft hit the atmosphere, but, with a dead service module, the LM would have to do all the work, including jettisoning itself. Nothing of the sort had ever been tried before. Deiterich had a couple of ideas, which he jotted down.
Many of the flight controllers on duty now would be on duty again three days later during reëntry. Behind Deiterich, at the CAPCOM’s console, Joseph Kerwin, who had succeeded Lousma at seven-thirty that morning, was talking with the astronauts in the spacecraft. Kerwin, a trim, clean-cut man, was a commander in the Navy Medical Corps; born in Oak Park, Illinois, in 1932, he graduated from Northwestern University Medical School in 1957 and became an astronaut in 1965. Kerwin was having a hard time hearing the Apollo’s crew, because the spacecraft’s amplifier had been turned off to save power. He had the volume on his headset turned up so high that hours after he went off duty he was still deafened. In spite of the crackling in his headset, he managed to catch one unexpected statement. Loud and clear, and apropos of nothing in particular, Lovell said, “Joe, I’m afraid this is going to be the last moon mission for a long time.” That was not the kind of talk that Lovell’s superiors expected to hear from one of their astronauts under any circumstances. (This was the only indiscretion, if that is the word for an honest doubt, an astronaut committed during the whole flight. Lovell’s fears did not come true, though Apollo 13 may have been a factor in NASA’s pending decision to drop two of the then six remaining Apollo flights. However that may be, some design changes were to be made in the spacecraft before the next mission to prevent another such accident from happening. All wires inside the cryogenic tanks were to be insulated with stainless steel; a third oxygen tank was to be added to the service module, at some remove from the other two tanks; and a battery capable of powering the command module home from any point in its orbit was to be added. Some alterations were also to be made in the Control Room: the EECOM’s console would be provided with a better warning system, and the philosophy behind the training simulations would change so that, as Reed would say later, “They can throw anything at us they want, and we won’t object.”)
When Lovell woke up Haise at about ten o’clock in the morning, he asked him how he had slept. Haise hadn’t slept well at all. Shortly afterward, Lovell and Swigert disappeared upstairs into the command-module bedroom. They didn’t sleep very well, either. The brilliant sun kept streaming in through the windows as the spacecraft rolled about, making disconcerting stabs of light. At Lovell’s suggestion, they pulled the shades on the windows. But without benefit of sunlight the cabin got very cold, and without electrical power it didn’t warm up again.
The main business Tuesday afternoon was preparing for the PC+2 burn, which was to take place at eight-thirty that evening. First, the astronauts would have to make sure that the alignment of the guidance platform was still accurate, for the gyroscopes that kept the small metal platform stationary could gradually drift out of line, imparting errors. Ordinarily, an astronaut seeking to check the alignment punched into his computer a request that it find a particular guide star. The computer, using the platform as its reference, swung the spacecraft to the right attitude to bring the star into view, and then the astronaut squinted through a telescope—the Alignment Optical Telescope, or A.O.T.—to see if the star was neatly centered in the telescope’s field of vision. If the A.O.T.’s aim was off, he computed the angle of error, which was also the degree of error in the alignment, and punched the correction into the computer. Doing this now was out of the question, because clouds of debris particles from the exploded tank surrounding the spacecraft shone so brightly in the sunlight that they completely obscured the stars. That morning, the Lead GUIDO, Kenneth Russell—a tall, curly-haired man, who sat alongside Deiterich and Reed—had suggested that instead of using the guide stars the astronauts check the platform against the sun, which would be a good deal easier to see in the blizzard of particles. Deiterich had complained that a sun check would not be exact enough; whereas a star is a precise pinpoint of light, the sun’s disc is so big that a check based upon it would be accurate only to within two degrees. However, Russell had nothing better to offer, and Deiterich couldn’t think of anything better himself, so he agreed to accept the two-degree error.
What had made him hesitate at the time was uncertainty whether the error could be corrected later, because the TELMUS had told him that the guidance platform would have to be turned off immediately after the PC+2 burn and kept off all the way back to earth, and Kranz had indicated that there would be no reprieve this time. However, Reed, the Lead FIDO, had found a way out: he had remembered from Apollo 8 a trick for tweaking up the trajectory on the way back to earth without the platform. An alignment involving the earth’s terminator, it was almost as simple as a sailor’s using the North Star to steer by, but without it Deiterich would never have been willing to accept the two-degree error now.
As Lovell veered the spacecraft in search of the sun, he muttered that he didn’t “have all the confidence in the world in this sun check.” When the sun appeared in the window, Lovell, momentarily leaving the controls, squinted through the Alignment Optical Telescope. “I’ve got it!” he said, but just then the LM lurched and the sun disappeared from view. The problem was that the A.O.T. was fixed rigidly inside the LM’s window—it didn’t swivel like a simpler telescope in the command module—and consequently Lovell had to aim it by maneuvering the LM, which of course couldn’t move with the necessary precision as long as the command and service modules were attached. With Haise’s help, he managed to get the sun lined up on the cross hairs long enough to align the platform up to the two-degree limit. Kranz, who was back on duty now along with the White Team, was not satisfied—he hoped they would be able to get a finer alignment on a star a little later, when the spacecraft would be in the moon’s shadow and there would be no more glare from the sun.
Though the
astronauts had not had much time to think about the moon, they were so close to it now that it overflowed the spacecraft windows, filling the cockpit with cold white light. The light, however, lessened and lessened, for they were moving around to the moon’s dark side, and at last the moon and the sun as well suddenly vanished. So did their own dazzling halo of debris. The sky outside was now calibrated with precise pinpoints of light, suitable for a star check. However, whenever the astronauts got one of the guide stars in view, it snuffed out—although their debris no longer glowed in the sunlight, it was still there and made black splotches that obliterated whole constellations. At last Kranz told Lovell to stop chasing after them—he was using up too much thruster fuel.
The spacecraft was going around the moon like a boat rounding a buoy. The nearer to the moon the spacecraft came, the faster it moved; it was travelling at six thousand miles an hour now—three times its speed at the time of the accident. The earth sank nearer and nearer the moon’s horizon, and then it, too, disappeared. The astronauts would be out of touch with Houston for about twenty-five minutes—until they emerged on the other side. The orange light on the upper left of the FIDO’s console stopped its constant flickering, and he knew that the telemetry from the spacecraft was no longer reaching the computers downstairs. The flight controllers stood up, stretched, and began talking to each other face to face, without benefit of the loop. Normally, the first passage of a spacecraft behind the moon was a suspenseful time for those waiting on earth, but the Apollo 13 mission had been so suspenseful already that most of the flight controllers regarded the period of radio silence as a breather.
The astronauts regarded it as a breather, too, for the pass behind the moon gave them their only chance to take a close look at it; at pericynthion, they were only a hundred and thirty miles from its surface. Before that, the sun had popped up into the sky again, so that they could see the ground. In the early dawn, the mountains below cast shadows longer than their own height—the moon itself looked dappled and dark—but as the spacecraft hurtled on, coming ever closer, the shadows shortened and the ground became increasingly bright. The inside of the spacecraft became brighter, too, and the astronauts put away the flashlights they had been using. Lovell had circled the moon ten times on the Apollo 8 mission, but Swigert and Haise were seeing it for the first time. Coming so far to see what others had seen before, and better, was anticlimactic, but although they were not the first to see the moon so close, they had the disquieting feeling that they could well be the last, and this gave their observations a compensating urgency. The back of the moon was a jumble of whitish highlands, with here and there a small black mare nestled among the hills like an alpine lake. Haise clicked away with his camera at one of the black spots, the Crater Tsiolkovsky, until it was lost again in the folds of the mountains. The photographs proved to be the most detailed ever taken of the area, one of the most interesting on the moon’s back side. At pericynthion, Lovell pulled the two other men away from the window, reminding them that they had a burn to do in two hours.
On the ground, Kranz, too, was getting nervous about the PC+2 burn, in part because the FIDO had reported some unexplained changes in the spacecraft’s velocity. The changes were all the more perplexing because the venting from the oxygen tanks had almost certainly stopped by now, and this was the only cause of such aberrations Kranz or the FIDO could think of. Of course, any unpredictable last-minute changes in the spacecraft’s speed—and hence in its trajectory—would further complicate the planning for an accurate burn. Above all else, Kranz was anxious that nothing go wrong with the PC+2 burn and knock the spacecraft off the return trajectory that everybody had worked so hard the night before to achieve. On the radio, the CAPCOM reminded Lovell that he should cut short the burn at the first sign of trouble; the burn could be done again any time in the next several hours. There was a new CAPCOM now; Kerwin had passed on the crackling headset to Vance Brand, a thirty-eight-year-old graduate of the University of Colorado, who had been a test pilot with the Lockheed Aircraft Corporation before becoming an astronaut, in 1966. Brand, a stocky man with light hair, helped out in the command-module simulator between shifts as CAPCOM. The idea now was to speed up the spacecraft so that it would arrive at its perigee about nine hours sooner; not only would this bring the astronauts back earlier but it would move the landing site from the Indian Ocean to the southwest Pacific, a distance of some ten thousand miles. If the burn had to be cut short, the astronauts could come down anywhere between the two points, and, accordingly, the RETRO on duty, Bobby Spencer, drew a line between them on a map and passed the map on to the Recovery Officers, who would have to be prepared to rescue the astronauts anywhere along it.
The Recovery Officers, who now had to compile a list of all shipping within striking distance of the line, were already nervous, because their meteorologists had announced that a hurricane—Tropical Storm Helen—was heading for approximately the same spot in the Pacific as the astronauts. The Recovery Officers suggested that the astronauts land somewhere else on that longitude—a little east or west. Deiterich, who had been up now for almost twenty-four hours, and who had the plans for the burn all set, strode into the Recovery Room and, as he put it later, “really hounded those guys until I got them to admit that they didn’t have enough of a handle on the weather to say what would happen in two days’ time.” RETROS sometimes were as tough on Recovery Officers as they were on mechanics and electricians.
The spacecraft had rounded the moon and was heading back toward the earth. It was still travelling at over five thousand miles an hour, but the higher it rose from the moon the slower it would go, until the next morning, at the crossover point into the earth’s gravity, it would be travelling at less than three thousand miles an hour. At the moment, it was moving so quickly that Haise felt as if he were in a jet plane taking off from a short runway; when he stole a glance out the window, the spacecraft seemed to be rising straight up from the moon. Immediately below, he could see Censorinus, a crater so sharp that it seemed the spacecraft might have just been ejected from it. To the west of Censorinus he could make out Tranquillity Base, where the Apollo 11 astronauts had landed nine months before. He couldn’t see the Fra Mauro hills, where he and Lovell had been supposed to land the next day, nor was he ever able to see the crater that Lovell and the other Apollo 8 astronauts had named for him. Brand’s voice came in over the crackling radio to report that the booster had hit the moon and made a crater that (on the basis of seismic data) was probably a hundred and twenty feet in diameter, but Haise couldn’t see that, either. However, he told Brand he was glad to hear that something had worked right on this flight.
Brand was talking to the astronauts less now, for he knew that they were busy. Ten minutes before the burn, Kranz checked with each flight controller in turn to make sure each was ready. At the back of the Control Room, the visitors’ gallery was filling with people who wanted to be present; there was even more NASA brass than there had been that morning, for Dr. Thomas O. Paine, who was then the NASA Administrator, and Dr. George M. Low, the Associate Administrator, had flown down from Washington. There was a spectator up in the spacecraft as well, for Swigert was in the LM, looking over Haise’s and Lovell’s shoulders. Ordinarily, command-module pilots were not present for lunar-module rocket burns. Swigert, who had nothing to do himself, was feeling like a third wheel. Everyone was tense. Brand, who was supposed to say “Mark!” to inform the astronauts when there were exactly forty seconds to go, said “Mark!” by mistake three minutes ahead of time—an understandable mistake, because there were several electronic clocks at the front of the Control Room counting down the time to different events, and it was easy to look at the wrong one. Fortunately, one of the astronauts caught the error.
At the right moment, Brand called out “Mark!” again, and just forty seconds later Lovell, his hand on the throttle, turned on the LM’s main rocket. Because—like the free-return maneuver—this was a docked burn, Lovell had to do the throttling
manually; even though the computer was what flight controllers called “up and running,” it was not programmed for throttling a docked-DPS burn. It would, however, control the guidance and turn the rocket off when the spacecraft had reached the proper acceleration; one of the guidance instruments could measure increases or decreases in speed. Lovell made the burn in three separate stages, so that it could be stopped more easily in case of trouble. First, he throttled the rocket up to ten per cent of its thrust for five seconds, to warm it up. Then he brought it up to forty per cent of its thrust for twenty-one seconds to trim the gimbals. Any problems with the rocket’s firing would show up now. In Houston, the Control Officer, Richard Thorson, studied his telemetry. When the CONTROL was sure the burn was going smoothly, Lovell brought the rocket up to full thrust for almost four minutes. The computer turned off the rocket only thirteen-hundredths of a second after the time predicted to reach the right speed, which Deiterich and Spencer thought was surprisingly accurate for a manual docked firing. Now that the astronauts would not be landing in the Indian Ocean, the Bordelon was called off, and the special crane was taken off “alert” at Norfolk.
Thirteen: The Apollo Flight That Failed Page 7