4 ms·

If Wikipedia is to be believed, even if a Challenger-like disaster could be made survivable, it would require quite radical and undesirable changes to the orbit

by qntm 16y ago

If Wikipedia is to be believed, even if a Challenger-like disaster could be made survivable, it would require quite radical and undesirable changes to the orbiter. http://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disaster#Cause_and_time_of_death http://en.wikipedia.org/wiki/Space_Shuttle_Challenger_disast... http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes#Ejection_escape_systems http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes#Eject... NASA playing hide-and-seek with the true fates of the Challenger crew is deplorable, but not taking the steps you describe - before and after the disaster - was a conscious acceptance of risk.

rtyuioikujhy 16y ago
the difficulty isn't just making this accident survivable, it's making any other accident at any other stage of the flight survivable. So any escape system that would work for the specific Challenger failure - supersonic but at regualr aircraft altitude - wouldn't work for say a pad explosion, or a failure at higher altitude, or a failure where the boosters didn't separate, or a crash on landing or ..... Fitting a dozen different ejection seats to swap between during takeoff and landing is tricky!
- starpilot 16y ago
  Not really. Zero-zero ejection seats have been around for decades and function from zero altitude and airspeed to supersonic speeds and higher altitudes (50,000+ ft). These will work during crashes. The F-35 and AV-8B can operate at low enough speeds (hover, or hover transition) that the canopies are laced with explosive cord to shatter the glass (polycarbonate) out of the pilot's way (normally, the canopy would fly aftward from forward flightspeed). SR-71 pilots wore space suits so that they could endure such high altitude egresses, which would certainly protect at lower altitudes as well. We have ejection systems that work in most flight regimes. I don't see significant reasons why a crew escape capsule would not work for even higher altitudes and speeds. Not saying it would be easy, though. For reentry safety, the best approach IMO is reducing reentry speeds via a lifting body fuselage. This is what SS1 uses. With drag bodies (e.g. Apollo capsule) there's all this worry over heatshields and reentry angle; with a lifting body, the vehicle glides into the atmosphere subsonically and heating is a nonissue. SS1 has minimal heat shielding, and no active cooling. A capsule is apparently simpler to design and easier to understand than something more airplane-like, but so is an ornithopter over a fixed-wing aircraft (kids ask how planes fly without moving their wings, because flapping flight is more obvious). One design requires delicate control and handling though, while the other is elegantly robust, more reliable, and safer.
  - rtyuioikujhy 16y ago
    Ejector seats would work for a challenger stage accident. The first shuttle with only 2 pilots on board did have aircraft style ejector seats. The problem comes when you have a crew of 7 on two levels - you could have down/side-ward firing seats, as used on some B52 variants, but that compromises the heat shield. But the most dangerous part of the flight is on the pad, a seat capable of firing you horizontally far enough to be clear of an explosion on the pad would be difficult - you would probably need the entire crew compartment to eject on it's own set of rockets - but this wouldn't work on landing, the other dangerous stage. Then there is the added danger of the rest of the flight - when inside the pressure hull you have the rockets necessary to blow a 2ton escape pod 3-5km clear of a pad fire.

by qntm 16y ago

rtyuioikujhy 16y ago

the difficulty isn't just making this accident survivable, it's making any other accident at any other stage of the flight survivable. So any escape system that would work for the specific Challenger failure - supersonic but at regualr aircraft altitude - wouldn't work for say a pad explosion, or a failure at higher altitude, or a failure where the boosters didn't separate, or a crash on landing or ..... Fitting a dozen different ejection seats to swap between during takeoff and landing is tricky!

starpilot 16y ago
Not really. Zero-zero ejection seats have been around for decades and function from zero altitude and airspeed to supersonic speeds and higher altitudes (50,000+ ft). These will work during crashes. The F-35 and AV-8B can operate at low enough speeds (hover, or hover transition) that the canopies are laced with explosive cord to shatter the glass (polycarbonate) out of the pilot's way (normally, the canopy would fly aftward from forward flightspeed). SR-71 pilots wore space suits so that they could endure such high altitude egresses, which would certainly protect at lower altitudes as well. We have ejection systems that work in most flight regimes. I don't see significant reasons why a crew escape capsule would not work for even higher altitudes and speeds. Not saying it would be easy, though. For reentry safety, the best approach IMO is reducing reentry speeds via a lifting body fuselage. This is what SS1 uses. With drag bodies (e.g. Apollo capsule) there's all this worry over heatshields and reentry angle; with a lifting body, the vehicle glides into the atmosphere subsonically and heating is a nonissue. SS1 has minimal heat shielding, and no active cooling. A capsule is apparently simpler to design and easier to understand than something more airplane-like, but so is an ornithopter over a fixed-wing aircraft (kids ask how planes fly without moving their wings, because flapping flight is more obvious). One design requires delicate control and handling though, while the other is elegantly robust, more reliable, and safer.
- rtyuioikujhy 16y ago
  Ejector seats would work for a challenger stage accident. The first shuttle with only 2 pilots on board did have aircraft style ejector seats. The problem comes when you have a crew of 7 on two levels - you could have down/side-ward firing seats, as used on some B52 variants, but that compromises the heat shield. But the most dangerous part of the flight is on the pad, a seat capable of firing you horizontally far enough to be clear of an explosion on the pad would be difficult - you would probably need the entire crew compartment to eject on it's own set of rockets - but this wouldn't work on landing, the other dangerous stage. Then there is the added danger of the rest of the flight - when inside the pressure hull you have the rockets necessary to blow a 2ton escape pod 3-5km clear of a pad fire.