Sadly, for the crew, it wasn't:
Myth #3: The crew died instantly
The flight, and the astronauts’ lives, did not end at that point, 73 seconds after launch. After Challenger was torn apart, the pieces continued upward from their own momentum, reaching a peak altitude of 65,000 feet before arching back down into the water. The cabin hit the surface 2 minutes and 45 seconds after breakup, and all investigations indicate the crew was still alive until then.
What's less clear is whether they were conscious. If the cabin depressurized (as seems likely), the crew would have had difficulty breathing. In the words of the final report by fellow astronauts, the crew “possibly but not certainly lost consciousness,” even though a few of the emergency air bottles (designed for escape from a smoking vehicle on the ground) had been activated.
The cabin hit the water at a speed greater than 200 mph, resulting in a force of about 200 G’s — crushing the structure and destroying everything inside. If the crew did lose consciousness (and the cabin may have been sufficiently intact to hold enough air long enough to prevent this), it’s unknown if they would have regained it as the air thickened during the last seconds of the fall. Official NASA commemorations of “Challenger’s 73-second flight” subtly deflect attention from what was happened in the almost three minutes of flight (and life) remaining AFTER the breakup.
