6 ms·
You're not wrong, but I think it's cool how much safer the generic capsule design is than something like the Shuttle. Really the Shuttle got a whole lot wrong—h
by caconym_ 6y ago
You're not wrong, but I think it's cool how much safer the generic capsule design is than something like the Shuttle. Really the Shuttle got a whole lot wrong—heat-intolerant aluminum structure and critical, sensitive machinery directly beneath a layer of tiles so fragile you can crush them in your hands (IIRC).
SpaceX's Starship will probably be a lot more tolerant to defects in the heat shield because of the relatively heat-tolerant steel underneath, but landing safely relies on the operation of massive aero surfaces and a relight of the engines with thrust vectoring. It'll be interesting to see how that goes.
- zitterbewegung 6y agoThis is at the stage where you cant really make assumptions about what may happen because you don't know what could go wrong. (A.K.A you don't know what you don't know).
- free_rms 6y agoI'm not claiming that OP or I are experts, but there's actually a pretty big body of knowledge for capsule re-entry. It's more 'known problems' than 'unknown unknowns'.
- caconym_ 6y agoAll you need to bring a traditional capsule design down to ~sea level terminal velocity safely is a blunt body with offset CG and the kind of circular ablative heat shield that's been shown over decades to be simple, safe and reliable. You don't even need active control unless you want more precision for hitting your landing target. The biggest risk, assuming your position and velocity were correct at interface, is the parachutes–which is why SpaceX took so much time testing and refining them. Things can always go wrong, but we know enough about both classes of vehicle to be able to say that the Shuttle's design was in general terms both more complex and more risky. This is slightly off topic, but the Shuttle was horribly unsafe on the way up as well as on the way down. Using solid rocket boosters with no means to get the crew safely off the stack until they stop burning is, for lack of a better word, demented. The Crew Dragon/Falcon 9 stack offers realistic abort modes from the moment fueling begins until the vehicle reaches its intended orbit.
- one2know 6y agoThe Shuttle was built to bring down soviet spy satellites and spacecraft, so in that regard, it was the best design made.
- whoisthemachine 6y agoHuh interesting. Do you have sources for that information?
- kraemahz 6y agoIn the time it took you to ask, you could have been searching. This is the first result on "shuttle design airforce" in Google: https://en.wikipedia.org/wiki/Space_Shuttle_design_process#Air_Force_involvement https://en.wikipedia.org/wiki/Space_Shuttle_design_process#A...
- redis_mlc 6y agoThe main concern of the Soviets was that the Shuttle could swoop down and drop bombs without warning. (Both Reagan and the Soviet top leadership didn't care about MAD, they cared about practical methods to stop incoming missiles. To get the arms limitations agreements signed, Reagan allowed the Soviets an exception to the anti-ABM ban to allow a ring of anti-ABM sites around Moscow, which exists until today. The "Star Wars" kinetic interception methods are also likely still active, though the laser methods probably never worked well.)
- js2 6y agoThere was at least one mission to retrieve a satellite (not Soviet): https://www.nytimes.com/1990/01/07/us/space-shuttle-poised-to-begin-mission-to-retrieve-a-satellite.html https://www.nytimes.com/1990/01/07/us/space-shuttle-poised-t...
- one2know 6y agoI don't have access to classified military secrets, but you don't think they would build a vehicle that could return 15 tons of payload to earth to retrieve US satellites? US could just build and launch a new satellite easier and cheaper than bring one down to fix only to launch it again. Obviously there is the movie about Salyut 7 that depicts the shuttle trying to capture the station. Salyut 3 had a machine gun attached to it.