3 ms·
The real mistake happened around 1976 when they settled on the basic design which they estimated had a 2-3% chance of blowing up on any launch. From what I rem
by tremon 6y ago
The real mistake happened around 1976 when they settled on the basic design which they estimated had a 2-3% chance of blowing up on any launch.
From what I remember from this case study in university wasn't that the launch risks weren't ignored, they were evaluated and deemed acceptable. The problem was that the effect of outside (weather) temperature on the efficacy of the rubber seals in the fuel conduits wasn't factored into the risk assessments.
After-the-fact analysis of the data from previous launches showed a clear relationship between the outside temperature during launch and the amount of fuel (or oxygen, don't remember) leaked from the joints. But this relationship wasn't known before launch, because (IIRC) nobody had done such a temperature-gradient analysis on the launch data before.
- bigbubba 6y ago> fuel (or oxygen, don't remember) leaked from the joints. The o-rings were in joints connecting sections of the solid rocket boosters (SRBs). The gas blowing past them was the superheated exhaust from the burning solid propellant. This plume of exhaust gas impinged on a strut attaching the SRB to the big orange external fuel tank (ET) (which held liquid hydrogen and oxygen for the space shuttle main engines located on the orbiter.) This soon lead to the damaged SRB detaching from the ET and colliding with it. The ET then catastrophically failed, creating a huge fireball. Some of the crew were likely still alive until their compartment hit the ocean.