Since I spoke a bit about the Crew Dragon launch in May I thought I’d follow up by announcing that the crew is now back, having successfully splashed down in the Gulf of Mexico, and now being released from the capsule onto a medical facility on the ship that retrieved them (they are ok, its just routine to have them looked over).
Basically, when the capsule returns, after some maneuvers that lead to the craft ‘de-orbiting’, it more or less becomes like a falling rock. But, there are some issues with that. Its a falling object that gets quite hot as it slows down and experiences friction with the increasingly dense atmosphere. This leads to a heating of about 3500 degrees F. That’s hot! We don’t want the space craft or anyone in it to be in danger, so we need a way of absorbing the heat. That’s the purpose of a heat shield on the surface of the craft (the “bottom” for lack of better term) that hits the atmosphere first. It was damage to this sort of heat absorbing material at launch that lead to the demise of the Space Shuttle Columbia in 2003.
But there are still problems even if the capsule gets through this point. The space craft is still going fast, in the hundreds of miles per hour range, so needs to slow down. To do this, parachutes are deployed and slow the craft down to under less than 20 miles per hour (less that 30-35 or so km/hr). Now, the capsule can hit the water without there being much of a problem for craft or crew!
So, does science fiction treat this sort of thing realistically? I think by now, since we’ve doing this (more or less, but with breaks and landings instead of splashdowns) since the 1960’s, they usually get parts of it right, but speed up the process a bit too much (in interest of not making splashdown be 1 hour of a 2 hour movie) , and sometimes skipping details.
If you want to see more about this sort of thing, check out my (Steve Bloom) book, The Physics and Astronomy of Science Fiction, available via Amazon or direct from the publisher, McFarland Inc.