After a journey lasting up to 13 days, and having taken men further from Earth than they would go for at least another two generations, an Apollo lunar mission ended with a hefty thump on the surface of the ocean. With luck, the spacecraft would catch the tip of the descending swell which would soften its impact. Not so for the crew of Apollo 12. Luck went against them, and especially against the skull of LMP A1 Bean when rough waves and bad timing created a very hard impact, as Conrad explained afterwards: “We really hit flatter than a pancake, and it was a tremendous impact. Much greater than anything I’d experienced in Gemini. The 16-millimetre camera, which was on the bracket, whistled off and clanked A1 on the head to the tune of six stitches. It cold-cocked him, which is why we were in Stable II.”
In the water, the command module had two stable modes of floating – right-way up, known as ‘Stable Г; or upside-down, or ‘Stable IT, which left the crew hanging uncomfortably in their straps facing downwards. One of Bean’s tasks was to close two circuit breakers mounted by his side to let power reach the pyrotechnic circuits, so that when Conrad threw a switch, guillotines would cut the main parachutes free from the spacecraft. However, as Bean had been temporarily
Apollo 12’s CM in its ‘Stable ІГ attitude soon after landing. (NASA)
knocked unconscious by the dislodged camera, the cutters were not fired and the capsule was pulled over.
"He was out to lunch for about five seconds,” continued Conrad. "Dick was hollering for him to punch in the breakers, and in the meantime, I’d seen this thing whistle off out of the corner of my eye and [Bean] was blankly staring at the instrument panel. I was convinced he was dead over there in the right seat, but he wasn’t, and finally got the breakers in. By that time, we’d gone Stable II, which was no big deal.”
Apollo 8’s CM also ended upside-down. When it hit in the dark, Borman got drenched with a few litres of sea water. "The one item that we were perhaps not expecting was the impact at touchdown,” he explained afterwards. "There was a severe jolt and we got water in through the cabin repress valves even though they were closed. A good deal of water came in the cabin pressure relief valve.” Distracted by the torrent of water that had entered the cabin, he did not release the chutes before they pulled the spacecraft over.
With the parachutes cut free, the SECS pyro system was safed for the last time. Beneath where the parachutes were packed, three flotation bags had been installed which the crew inflated with stored gas to upright an inverted spacecraft. Even if the spacecraft was already floating upright, the bags were inflated in case a freak wave should flip it over.
There seemed to be an evens chance that the CM would end up in the ‘Stable IT position. For Apollo 16, it took a bit longer to get it upright. "It may have taken us four or five minutes to upright,” explained Young. "The centre bag apparently didn’t fully inflate. It’s supposed to be the one that inflates first. But the other two bags were certainly inflated. It uprighted just like normal.”
“I felt a solid jolt.1′ was Collins’s recollection of the Apollo 11 impact. “It was a lot harder than 1 expected.’’ Aldrin had tried to be ready to close the circuit breakers to allow Armstrong to release the chutes as quickly as possible, but the force of the impact foiled him. "It pitched me forward with a little bit of sideways rotation.” he said. "I [had] my fingers quite close to the circuit breaker. The checklist fell, and the pen or pencil, whatever I had. dropped. It didn’t seem as though there was any way of keeping my fingers on the circuit breakers.’’
Once they had the spacecraft upright and stable, a dye was released into the water if required, to aid search and rescue, and the post-landing vent (PLV) could be opened to let fresh air in. Mindful of NASA’s need to keep supposed lunar bugs at bay, Collins, while somewhat sceptical of the fear, tried his best not to leave the vent open. "The big item for us was that we not contaminate the world by leaving the post-landing vent open. We had that underlined and circled in our procedures to close that vent valve prior to popping the circuit breakers on panel 250. I’d like to say for the following crews that they pay attention to that in their training. If you cut the power on panel 250 before you get the vent valve closed, in theory, the whole world gets contaminated, and everybody is mad at you.”
Dick Cordon pointed out how this vent gave the Apollo 12 crew some problems, given that they were floating on heavy seas. "The procedures say. of course, to open the PLV duets. With that rough water out there, when we did, we just took water in through the intakes and that fan just blew it into the spacecraft. After a while, we got tired of getting wet so we just turned the PLV duct off. We just turned it off, and then when we got real warm again, I turned it back on just to let some more air in."