As o11c mentioned, they only existed for the first few flights, the ones that only had two crew. It wasn't possible to have the election seats with the full sh

As o11c mentioned, they only existed for the first few flights, the ones that only had two crew. It wasn't possible to have the election seats with the full shuttle crew so they were removed. The ejection seats were essentially the same as those used in the SR-71, so they were survivable at shockingly high speeds and altitudes.