Originally Posted by Excargodog

The original first few space shuttle flights the two pilots aboard sat on ACES-II ejection seats. I’ve never figured out what NASA was thinking with that. They couldn’t eject after SRB ignition because they would have been cremated until they lose those SRBs. That happened 24 miles up when they were hypersonic. Couldn’t eject in atmosphere AT ALL except in the last minute or so before landing because they were still supersonic and the q forces would have torn their limbs off. Only place they could safely eject was in orbit.

An Aces II air bottle was good for about 20 minutes.

They took them out for later flights...