[tzs]

I'd like both if I'm heading to space--I want my vehicle to not explode, and if it does explode I want a way to get back down to Earth reasonable safely.

At least several of the Challenger crew survived the explosion and were definitely conscious and functioning for at least several seconds afterwards, and oxygen use records indicate they were alive for the fall to the ocean (whether they were conscious or not for the whole fall depends on whether or not the cabin depressurized, which is not known).

So, parachutes for a Space Shuttle crew are not prima facie unreasonable. There are engineering issues, which ultimately were determined to make them not worth it.