Krista McAuliffe was selected by NASA to be part of the 25th Space Shuttle Mission. Her job would be to teach lessons to children all over the world from space. She and her backup, Barbara Morgan, took a year's leave of absence from teaching in order to train as astronauts as well as promote the Teacher in Space Project to the public.
The launch was originally scheduled for January 22, but was delayed for a number of reasons, including bad weather predictions. Challenger would have launched on January 27 but for the final delay, this time to have then-Vice President George Bush (Sr.) stop by to watch.
January 28 was an unusually cold morning, and concerns were expressed about the effects of the cold on the rubber O-rings that sealed the rocket boosters. Those who did so were overruled, and the launch went ahead.
One minute after launch, a small plume of flame appeared on one of the boosters. Nobody noticed at the time, and 68 seconds after launch the final air-to-ground communication from Challenger was heard: "Roger, go at throttle up." At 72 seconds, one of the boosters pulled away from the shuttle, and probably caused a sudden sideways movement. The cabin recorder has the voice of Pilot Michael Smith saying "Uh oh" a half-second after this. A second later, the breakup of Challenger began. It veered from its course and was torn apart by the abnormal aerodynamic forces.
The crew cabin detached in one piece and slowly tumbled and within 10 seconds was free-falling toward the earth. The "post-breakup trajectory" was nearly three minutes, and oxygen consumption (calculated by the unused air supply) indicates that the cres were probably still alive. How long they remained conscious is not known; If the cabin lost pressure, they would have passed out in a few seconds. The cabin hit the ocean surface at 207 mph (337 kph), creating deceleration of more than 200g. If they were still alive before it hit, they were not alive after.
The report of a biomedical specialist, released in July of the same year, stated:
The findings are inconclusive. The impact of the crew compartment with the ocean surface was so violent that evidence of damage occurring in the seconds which followed the explosion was masked. Our final conclusions are:
* the cause of death of the Challenger astronauts cannot be positively determined;
* the forces to which the crew were exposed during Orbiter breakup were probably not sufficient to cause death or serious injury; and
* the crew possibly, but not certainly, lost consciousness in the seconds following Orbiter breakup due to in-flight loss of crew module pressure.
There was no possibility of crew escape; the shuttle had not been designed with that need in mind.
McAuliffe's backup, Barbara Morgan, watched as the shuttle took off, cheering and clapping for her friends. You can see a clip of this on YouTube. At about 1:40 into the clip you hear a male voice say "That's not right". Gordon reacts, her hands flying up under her chin, and in a few seconds she leaves the shot. Those few seconds tell a story in body language.
Morgan continued to work with NASA on educational projects. Twelve years later, in 1998, Morgan became a full-time professional astronaut, and flew on a space shuttle mission to the International Space Station in August 2007. One need not imagine her thoughts at that time; they are available on YouTube.