If the weather holds, this afternoon we’ll be launching astronauts from Florida for the first time since 2011. I saw on the news last week that they’ll be wearing spiffy new suits for the launch.
Which got me to wondering about the old suits. Whenever a space shuttle launched or landed, the astronauts on board were wearing an orange suit. But whenever they were conducting an on-orbit EVA, they wore a white suit. The most obvious difference I can guess at is that the launch/return suit would only need enough of an air supply to keep its occupant alive for the longest possible contingency after closing their faceshield, which might be…what, 20 minutes? Whereas EVAs have lasted as long as 8 hours.
So what other differences were there between these two types of suit?
Great question. I imagine that the OP’s point about air supply would only determine what tank is attached to the outside of the suit, and not affect anything about the suit itself. Looking forward to other responses.
The flight suits used post-Challenger were the Advanced Crew Escape Suit (ACES, colloquially known as the “pumpkin suit”) is just a partial pressurize flexible flight suit. It does not have self-contained air supply other than a ~10 minute reserve, thermal regulation, or the other features of a primary life support system (PLSS) that would be needed in an extravehicular activity (EVA) suit. The NASA suits used for EVAs are the Extravehicular Mobility Unit (EMU) is a pressurized semi-hardshell with a PLSS, multiple garments for thermal regulation, communications equipment, a multi-part visor assembly, and the optional propulsive system (Simplified Aid For EVA Rescue or “SAFER”, intended only for contingency operations). The EMU is less a suit than a very small spacecraft that is primarily habitat.
I don’t know what those SpaceX ascent suits are built for but they look like a fancy track suit. I’m sure that is someone industrial designer’s idea of what a “modern” flight suit should look like but they are definitely built for appearance over function, and I personally wouldn’t put high confidence in one without seeing far more testing than what SpaceX has presented publicly. On the other hand, there is a very narrow range of in-flight failures that hypothetically could be survivable, and an ascent suit only provides a marginal improvement in survivability; the Shuttle crews flew in shirt sleeves after the first four checkout missions (where they wore modified SR-71 flight suits) and the suits would not have let the astronauts survive the failure of Challenger on STS-51-L nor did they save the crew on the re-entry failure of Columbia on STS-107.