The Mammoth Book of Space Exploration and Disasters

The understated report from the spacecraft tore though the control room like a bullet.

“Crew thinks they’re venting something,” Lousma said to the loop at large.

“I heard that,” Kranz said.

“Copy that, Flight?” Lousma asked, just to be sure.

“Rog,” Kranz assured him. “OK everybody, let’s think of the kind of things we’d be venting. GNC, you got anything that looks abnormal on your system?”

“Negative, Flight.”

“How about you, EECOM? You see anything with the instrumentation you’ve got that could be venting?”

“That’s affirmed, Flight,” Liebergot said, thinking, of course, of oxygen tank two. If a tank of gas is suddenly reading empty and a cloud of gas is surrounding the spacecraft, it’s a good bet the two are connected, especially if the whole mess had been preceded by a suspicious, ship-shaking bang, “Let me look at the system as far as venting is concerned,” Liebergot said to Flight.

“OK, let’s start scanning,” Kranz agreed. “I assume you’ve called in your backup EECOM to see if we can get some more brain power on this thing.”

“We got one here.”

The change on the loop and in the room was palpable. No one said anything out loud, no one declared anything officially, but the controllers began to recognize that Apollo 13, which had been launched in triumph just over two days earlier, might have just metamorphosed from a brilliant mission of exploration to one of simple survival. As this realization broke across the room, Kranz came on the loop. “OK,” he began. “Let’s everybody keep cool. Let’s make sure we don’t do anything that’s going to blow our electrical power or cause us to lose fuel cell number two. Let’s solve the problem, but let’s not make it any worse by guessing.”

Lovell, Swigert, and Haise could not hear Kranz’s speech, but at the moment they didn’t need to be told to keep cool. The moon landing was definitely off, but beyond that, they were probably in no imminent danger. As Kranz had pointed out, fuel cell two was fine. As the crew and controllers knew, oxygen tank one was healthy as well. Not for nothing did NASA design its ships with backup system after backup system. A spacecraft with one cell and one tank of air might not be fit to take you to Fra Mauro, but it was surely fit to take you back to Earth.

Lovell checked the readings for his remaining oxygen tank. Lovell:

The commander glanced at the meter and froze: the quantity needle for tank one was well below full and visibly falling, As Lovell watched, almost entranced, he could see it easing downward in an eerie, slow-motion slide. Lovell was put in mind of a needle on a car’s gas gauge. Funny how you can never actually see the thing budge; funny how it always seems frozen in place, but nevertheless makes its way down to empty. This needle, though, was decidedly on the move.

This discovery, horrifying as it was, explained a lot. Whatever it was that had happened to tank two, that event was over. The tank had gone off line or blown its top or cracked a seam or something, but beyond the very fact of its absence, it had ceased to be a factor in the functioning of the ship. Tank one, however, was still in a slow leak. Its contents were obviously streaming into space, and the force of the leak was no doubt what was responsible for the out-of-control motion of the ship. It was nice to know that when the needle finally reached zero, Odyssey’s oscillations would at last disappear. The downside, of course, was that so would its ability to sustain the life of the crew.

Lovell knew Houston would have to be alerted. The change in pressure was subtle enough that perhaps the controllers hadn’t noticed it yet. The best way – the pilot’s instinctive way – was to play it down, keep it casual. Hey you guys, notice anything about that other tank? Lovell nudged Swigert, pointed to the tank one meter, then pointed to his microphone. Swigert nodded.

“Jack,” the command module pilot asked quietly, “are you copying O₂ tank one cryo pressure?”

There was a pause. Maybe Lousma looked at Liebergot’s monitor, maybe Liebergot told him off the loop. Maybe he even knew already. “That’s affirmative,” the Capcom said.