The Mammoth Book of Space Exploration and Disasters

The next problem was that their angle of trajectory was becoming too shallow for re-entry – something was eroding it. Houston considered a small burn to correct the angle. The latest consumables report was favourable: electricity consumption was actually below their projections. Their speed was accelerating as the earth’s gravitational pull increased and that of the moon decreased.

Haise was on watch when:

Just as Haise approached the right-hand window, a chillingly familiar bang-whump-shudder shook the ship. He shot his hand out, braced himself against the bulkhead, and froze in mid-float. The sound was essentially the same as Monday night’s bang, though it was unquestionably quieter; the sensation was essentially the same as Monday night’s shudder, though it was unquestionably less violent. The locus of the event, however, was utterly different. Unless Haise was mistaken – and he knew he wasn’t – this disturbance had not come from the service module, at the other end of the Aquarius-Odyssey stack, but from the LEM descent stage below his feet.

Haise swallowed hard. This should be the helium burst disk blowing: if the ground has told you to expect a venting and a moment later your ship bangs and rocks, chances are the two are connected. But viscerally, Haise – the man who understood Aquarius better than anyone else on board – knew this wasn’t true. Burst disks didn’t sound this way, they didn’t feel this way, and, floating cautiously up to his porthole and peering out, he also saw that they didn’t look this way. Just as Jim Lovell had discovered vented gas streaming past his window more than forty hours ago, Haise, the LEM pilot, was alarmed to see much the same thing outside his window now. Drifting up from Aquarius’s descent stage was a thick white cloud of icy snowflakes, looking nothing at all like misty helium streaming from a burst disk.

“OK Vance,” Haise said as levelly as he could, “I heard a little thump, sounded like down in the descent stage and I saw a new shower of snowflakes come up that looked like they were emitted from down that way. I wonder,” he said somewhat hopefully, “what the supercritical helium pressure looks like now.”

Brand froze in his seat “OK,” he said. “Understand you got a thump and a few snowflakes. We’ll take a look at it down here.”

The effect of this exchange on the men in Mission Control was electric.

“You copy that call?” Dick Thorson, at the CONTROL console, asked Glenn Watkins, his backroom propulsion officer.

“Copied it.”

“How’s that supercrit look?”

“No change, Dick,” Watkins said.

“None?”

“None. It’s still climbing. That wasn’t it.”

“CONTROL, Flight,” Gerry Griffin called from the flight director’s station.

“Go, Flight,” Thorson answered.

“Got an explanation for that bang?”

“Negative, Flight.”

“Flight, Capcom,” Brand called.

“Go, Capcom,” Griffin answered.

“Anyone know what that bang was about?”

“Not yet,” Griffin said.

“Anything at all we can tell him, then?” Brand asked.

“Just tell him it wasn’t his helium.”

As Brand clicked back on to the air-to-ground loop and Griffin began polling his controllers on the flight director’s loop, Bob Heselmeyer at the TELMU station began scanning his console. Looking past the oxygen readouts, past the lithium hydroxide readouts, past the CO₂ and H₂O readouts, he noticed the battery readouts, the four precious power sources in Aquarius’s descent stage that, working together, were barely providing enough energy for the exhausted, overtaxed ship. Gradually, the readout for battery two – just like the too easily recalled readout for Odyssey’s O₂ tank two – had slipped below what it should be and was failing steadily.

If the data were right, something had arced or shorted in the lunar module’s battery, just as it had arced or shorted in the service module’s tank on Monday night. And if there had been a short, the battery, like the tank would soon go off line killing fully one quarter of a power supply that Houston and Grumman were rationing down to the last fraction of an amp. The numbers on the screen were too preliminary to be conclusive – too preliminary even for Heselmeyer to pass them on to Griffin. And if Heselmeyer didn’t pass them on to Griffin, Griffin couldn’t pass them on to Brand, and Brand couldn’t pass them on to Haise.

At the moment, that was probably just as well. Standing at his window and looking out at the growing cloud of flakes surrounding the bottom of his LEM, Fred Haise had more than enough burdens of command.