[Moonman62]

Remember that the seats are designed to hold astronauts wearing full pressure suits.

If they are, then those suits didn't help much during the Columbia and Challenger disasters.

[tanknetter]

If they are, then those suits didn't help much during the Columbia and Challenger disasters.

The full pressure suits were discontinued after the initial test flights. Instead the astronauts launched in flight suits with lightweight helmets.

They were re-instituted after Challenger, not because they would have saved the Challenger astronauts (they wouldn't have), but because they permitted a higher degree of survivability under a wider range of accident scenarios.

Breakup of vehicle at 200,000 feet and somewhere around Mach 15, as happened with Columbia, wasn't one of those scenarios. However, had Columbia made it further along and NASA determined that the damage would prevent a safe landing (say if the wing structure survived, but the port-side landing gear sensors showed it was destroyed) the astronauts would have been able to successfully bail out above 60,000 feet.