kwan3217
Addon Developer
On reading the new STS-107 report, one thing I find amazing is how long the ship stayed intact after losing control. Columbia was a tough ship, and hung on a lot longer through much worse attitudes than I thought possible, almost a full minute cartwheeling through the sky at the wrong angle, and if the left wing had not already been compromised, who knows? Even flying at a 90deg angle of attack, it never exceeded its structural limits before the compromised left wing gave up.
Also: At mach 18, when hydraulics are lost and the flaps go flappy, they turn all the way up and put the vehicle in a near 90deg angle of attack. I didn't know such a thing was even possible, as whenever I do an entry, I have to fight with full body flap, full elevators, and a bit of pitch rcs, to even get it to near 38deg. Whenever I release the controls the angle of attack drops to near zero (where the windshield would melt). There is something very wrong with SSU's aero model, at least at high hypersonic.
So: The aero model needs serious work, and when the control surfaces fail at high mach, they go all the way up. If and when we ever do a damage model, we should take this into consideration.
It just seems that they were so close to at least a survivable accident. If all the hydraulics had not been lost, (Don't run all the hydraulics lines through the front half of the wing?) then they would have stayed in control for longer and gotten lower and slower before the RCS fuel did run out and they lost control that way. But, the ship would have been that much slower and that much less hard to survive. The report says the forward heat shield protected the crew module for a good several seconds after breakup, and if they had been lower and slower, the heat shield might have held on longer and maybe the crew module wouldn't have broken up. Then with a drouge or ribbon chute (which they didn't carry, but maybe should) they could have stabilized the crew module and bailed out.
However, I understand that the ship failed in an unanticipated way, and the next crew lost (on whatever ship they will be on) will probably be lost in an unanticipated way. You can't plan for everything and still have a ship light enough to fly. Planning for the last accident doesn't help.
Also: At mach 18, when hydraulics are lost and the flaps go flappy, they turn all the way up and put the vehicle in a near 90deg angle of attack. I didn't know such a thing was even possible, as whenever I do an entry, I have to fight with full body flap, full elevators, and a bit of pitch rcs, to even get it to near 38deg. Whenever I release the controls the angle of attack drops to near zero (where the windshield would melt). There is something very wrong with SSU's aero model, at least at high hypersonic.
So: The aero model needs serious work, and when the control surfaces fail at high mach, they go all the way up. If and when we ever do a damage model, we should take this into consideration.
It just seems that they were so close to at least a survivable accident. If all the hydraulics had not been lost, (Don't run all the hydraulics lines through the front half of the wing?) then they would have stayed in control for longer and gotten lower and slower before the RCS fuel did run out and they lost control that way. But, the ship would have been that much slower and that much less hard to survive. The report says the forward heat shield protected the crew module for a good several seconds after breakup, and if they had been lower and slower, the heat shield might have held on longer and maybe the crew module wouldn't have broken up. Then with a drouge or ribbon chute (which they didn't carry, but maybe should) they could have stabilized the crew module and bailed out.
However, I understand that the ship failed in an unanticipated way, and the next crew lost (on whatever ship they will be on) will probably be lost in an unanticipated way. You can't plan for everything and still have a ship light enough to fly. Planning for the last accident doesn't help.
