The Mammoth Book of Space Exploration and Disasters

“Do you think 37 minutes is enough?” Haise asked.

“Actually, no,” Lovell answered. “Jack,” he now said back to the Capcom, “we’ll give it a try if that’s all we’ve got, but could you give us a little more time?”

“OK, Jim, we can figure out a maneuver for any time you want. You give us the time, we’ll shoot for it.”

“Then let’s shoot for an hour if we can.”

“OK how about 61 hours and 30 minutes?”

“Roger,” Lovell said. “But let’s talk back and forth till then and make sure we get this burn off right.”

“Roger,” Lousma said.

The hour until the free-return burn would be a frantic one for the crew. In a nominal mission, the flight plan allowed at least two hours for the so-called descent activation procedure, the ritual of configuring switches and setting circuit breakers that preceded any burn of the LEM’s lower-stage engine. The crew would now have barely half that time to do the same job, and do it without sacrificing the necessary precision. On top of that, there was still the elusive fine alignment to establish, something that, with all the space-craft’s wild movements, Lovell was not yet close to accomplishing. But while the hour would be a breathless one aboard the ship, on the ground it would provide a chance to draw a breath.

Kranz’s team was working on how to make the consumable resources last long enough to bring them home. Lovell:

“For the rest of this mission,” Kranz began, “I’m pulling you men off console. The people out in that room will be running the flight from moment to moment, but it’s the people in this room who will be coming up with the protocols they’re going to be executing. From now on, what I want from every one of you is simple – options, and plenty of them.”

“TELMU,” Kranz said, turning to Bob Heselmeyer, “I want projections from you. How long can you keep the systems in the LEM running at full power? At partial power? Where do we stand on water? What about battery power? What about oxygen? EECOM” – he turned to Aaron – “in three or four days we’re going to have to use the command module again. I want to know how we can get that bird powered up and running from a cold Stop to splash – including its guidance platform, thrusters, and life-support system – and do it all on just the power we’ve got left in the reentry batteries.”

“RETRO, FIDO, GUIDO, CONTROL, GNC,” he said, looking around the room, “I want options on PC + 2 burns and mid-course corrections from now to entry. How much can PC + 2 speed us up? What ocean does it put us in? Can we burn after PC + 2 if we need to? I also want to know how we plan to align this ship if we can’t use a star alignment. Can we use sun checks? Can we use moon checks? What about Earth checks?

“Lastly, for everybody in this room: I want someone in the computer rooms pulling more strip charts from the time of translunar injection on. Let’s try to see if we can’t figure out just what went wrong with this spacecraft in the first place. For the next few days we’re going to be coming up with techniques and maneuvers we’ve never tried before. I want to make sure we know what we’re doing.”

Kranz stopped and glanced once more from controller to controller, waiting to see if there were any questions. As was often the case when Gene Kranz spoke, there weren’t any. After a few seconds he turned around and walked wordlessly out the door, heading back toward Mission Control, where dozens of other controllers were monitoring his trio of imperilled astronauts. In the room he left behind were the fifteen men he expected to save their lives.

Lovell gradually learnt how to control the attitude of the twin craft, the burn to correct trajectory for free return being so successful that no additional trim was required. Communication with Apollo 13 was subject to interference from its own third stage which was still following in the same trajectory.

After the free return burn Houston revised the astronauts’ work-rest schedule. One astronaut slept in Odyssey while the other two kept kept six-hour watches with an hour turn around. The hatch between was left open to allow enough air for a sleeping man but it was too cold and too noisy to sleep in Odyssey – Haise gave up after two hours and came back. They were all back on duty by 5 pm which was in time to prepare for the PC + 2 burn at 8.40.

Meanwhile there was a team change at Houston as Gerald Griffin’s Gold Team took over with Joe Kerwin as the new Capcom. The LEM’s descent engine was the main source of motive power available with its ascent engine only to be used if the descent stage was jettisoned. The descent stage contained most of the lander’s batteries and oxygen tanks. They had three possible burns: a superfast, medium or slow burn. A superfast burn had several disadvantages: it used up almost all the LEM’s fuel; they would have to jettison the service module as soon as possible; and they would land in the Atlantic where the US Navy had no recovery vessels. The medium burn was only a little slower than the superfast burn, its main benefit being that it retained the service module which protected the heat shield from the cold of space. They decided to take the slowest option.

Kraft and his flight directors let the arguments play out and watched, satisfied, as the men in the room settled for the slowest alternative. It was the choice the flight directors themselves had preferred, and it was the one the administrators would prefer. Now, as the arguments began to get into a consensus, Chris Kraft transformed the consensus into a decision.

“So it’s agreed,” he summed up. “At 79 hours and 27 minutes there will be an 850-foot-per-second burn for four and a half minutes, aiming for a Paciflc splash at 142 hours. If all goes well, Apollo 13 will be home by Friday afternoon.”

Bill Peters was TELMU in charge of the LEM’s consumable resources. He had worked out how many systems needed to be shut down to provide enough water and power to get them home. Water was needed as a coolant. Hundreds of systems were taken offline, making the LEM even more uncomfortable. There was one outstanding problem: how to keep the LEM’s oxygen clean. Odyssey needed some of the LEM’s power to bring its batteries back up to the required level.

The PC + 2 burn required precise alignment. Checking by star sightings was impossible because of the glare from sunlight reflecting off the debris. The controllers concluded that they would have to use the sun itself to check their alignment.

In the front row of Mission Control, Russell, Reed and Deiterich listened to the crew and said nothing. At the Capcom station, Brand held his tongue until he was called again. At the flight director’s station Griffin pulled his log toward him and scribbled the words “Sun check initiated.” On the air-to-ground loop, the fractured chatter continue to flow back from the crew.

“Yaw right side,” Haise could be heard saying. “Commander’s FDI.”

“Deadband option,” Lovell responded.

“Plus 190,” Haise said. “Plus 08526.”

“Give me 16—”

“I’ve got HP on the FDI—”

“Two diameters out, no more than that—”

“Zero, zero, zero—”

“Give me the AOT, give me the AOT—”

For close to eight minutes, the murmuring of the crew continued as Aquarius swung its bulk around and the controllers eavesdropped in silence. Then, from off the right side of the ship, Swigert thought he saw something: a small flash then nothing, then a flash again. All at once, unmistakably, a tiny degree of the solar arc flowed into the corner of the window. He snapped his head to the right, then turned to the left to alert Lovell, but before he could say anything, a shard of a sunbeam fell across the instrument panel and the commander, monitoring his needles, looked up with a start.

“Call it, Jack!” he said. “What do you see?”