How Artemis II returned to Earth |
The key event in the return of the Artemis II crew was the moment of real drama during what mission controllers call Entry Interface. The capsule is 400,000 feet above the Earth and still traveling at 25,000 miles an hour. They were among the fastest humans even though they did not break the incoming speed of the Apollo 10 mission. It is only fourteen minutes until splashdown in the Pacific, there is no turning back, no second chance, re-entry will happen no matter what.
A few hours earlier the crew donned their orange so-called crew survival suits and lowered their visors. In essence these are personal spacecraft providing everything they need to survive for up to six days. Their water-cooled inner suit was keeping them cool even though the cabin temperature was normal. Outside it was a very different matter.
When you return from the Moon, and they are only the tenth crew to do so, you are traveling very much faster than the velocity required to orbit the Earth, so this is no routine re-entry from the International Space Station. For days they have been making adjustments to their trajectory to align them with a small entry corridor which they must meet with exquisite precision. Failure to do so is unthinkable. To steep and they will burn-up, too shallow and they will bounce off the atmosphere and off into space only returning when all their oxygen is exhausted.
And so, at Entry Interface they begin slowing down from thirty-five times the speed of sound to a 17-mph splashdown just a few minutes later and the only thing that will slow them down is air, and the only thing keeping them alive is a three-inch thick heatshield made of........