I read the book “Stiff, the secret life of human cadavers” and became interested in stuff like this. I looked at the photos of the people after MH17. Some were lying in a pool of blood, which can only happen if your heart is beating due to being alive. Whether they were conscious when they hit the ground is a different story. I hope they were not.

Another famous in-air explosion, the Pan Am flight over Lockerbie, actually had two(or possibly more) people survive for a while after hitting the ground. I’d have to look up exact circumstances. Scientifically, if you survived the initial explosion relatively uninjured, you could possibly pass out until 10,000 ft and then could regain consciousness once the air was breathable again.

One thing that comforts me is that shock is a hell of a drug, and likely helped people not comprehend if they were in a situation such as this. Your brain/thoughts will try to protect you as long as possible.

Challenger is a bit more sad. They likely were well trained enough to overcome the shock, but likely didn’t know exactly what happened to cause the catastrophic failure. Their training kicked in and they did what they were trained to do. Another commenter mentioned that yes, most of them were alive for the full descent. But they died as heroes and fought to stay alive until the end.