flows.”
“We copy,” replied Lousma.
“And Jack,” Lovell added, “O2 cryonumber two tank is reading zero. Did you get that?”
“O2 quantity is zero,” Lousma repeated.
Bad as these developments were, Lovell had yet another problem to contend with. More than ten minutes after the initial bang, his spacecraft was still swaying and wobbling. Each time the command service module and the attached LEM moved, the thrusters would fire automatically to counteract the motion and try to stabilize the ships. But each time they appeared to have succeeded, the ships would start lurching again and the thrusters would resume their firing.
Lovell now took hold of the manual attitude controller built into the console, to the right of his seat. If the automatic systems couldn’t bring the ships to heel, perhaps a pilot could. Lovell was concerned about keeping the spacecraft under control for more than aesthetic reasons. Apollo ships on the way to the moon did not simply fly straight and true, with the command module’s nose pointed properly forward and the LEM attached to it like a big, ungainly hood ornament. Rather, the ships rotated slowly like a 1 rpm top. This was known as the passive thermal control, or PTC, position and was intended to keep the ships evenly barbecued, preventing one side from cooking in the glare of the unfiltered sun and the other side from freezing over in the deep freeze of shadowed space. The thruster convulsions of Apollo 13 had shot the graceful PTC choreography all to hell, and unless Lovell could regain control he faced the real danger of ultra-high and ultra-low temperatures seeping through the ship’s skin and damaging sensitive equipment. But no matter how Lovell worked his manual thrusters, he could not seem to settle his spacecraft down. No sooner had he stabilized Odyssey than it would go off line again.
For a pilot who had been taken to space three times before, with little more than nuisance problems from his equipment, this was getting to be intolerable. The electrical system in Lovell’s smoothly functioning craft had gone on the fritz, the safe harbor of home was shrinking in his mirror at better than 2,000 miles every hour, and now he faced even greater danger because something – who knew what – kept shoving his ship this way and that.
The commander let go of the attitude controller, punched open his seat restraint buckle, and floated up to the left-hand window to see if he could determine what was going on out there. It was the oldest pilot’s instinct in the world. Even when he was nearly 200,000 miles from home, in a sealed spacecraft surrounded by the killing vacuum of space, what Lovell really needed was a simple walk-around, a chance to make one slow 360 degree circuit of his ship, to eyeball the exterior, kick the tires, look for damage, sniff for leaks, and then tell the folks on the ground if anything was really wrong and just what had to be done to fix it.
However, he had to settle for a look out the side window, in the hope that whatever problem Odyssey might have would somehow make itself clear. The odds of diagnosing the ship’s illness this way were long, but as it turned out, they paid off instantly. As soon as Lovell pressed his nose to the glass, his eye caught a thin, white, gassy cloud surrounding his craft, crystallizing on contact with space, and forming an irridescent halo that extended tenuously for miles in all directions. Lovell drew a breath and began to suspect he might be in deep, deep trouble.
If there’s one thing a spacecraft commander doesn’t want to see when he looks out his window, it’s something venting from his ship. In the same way that airline pilots fear smoke on a wing, space pilots fear venting. Venting can never be dismissed as instrumentation, venting can never be brushed off as ratty data. Venting means that something has breached the integrity of your craft and is slowly, perhaps fatally, bleeding its essence out into space.
Lovell gazed at the growing gas cloud. If the fuel cells hadn’t killed his lunar touchdown, this certainly did. In a way, he felt strangely philosophical – risks of the trade, rules of the game, and all that. He knew that his landing on the moon was never a sure thing until the footpads of the LEM had settled into the lunar dust, and now it looked as if they never would. At some point, Lovell understood, he’d mourn this fact, but that time was not now. Now he had to tell Houston – where they were still checking their instrumentation and analyzing their readouts – that the answer did not lie in the data but in a glowing cloud surrounding the ailing ship.
“It looks to me,” Lovell told the ground uninflectedly, “that we are venting something.” Then, for impact, and perhaps to persuade himself, he repeated: “We are venting something into space.”
“Roger,” Lousma responded in the mandatory matter of factness of the Capcom, “we copy your venting,”
“It’s a gas of some sort,” Lovell said.
“Can you tell us anything about it? Where is it coming from?”
“It’s coming out of window one right now, Jack,” Lovell answered, offering only as much detail as his limited vantage point provided.
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.
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.
