The Unthinkable Fate of the Challenger Crew
The last words captured by the fight voice recorder in Challenger were not Commander Francis Scobee's haunting, "Go at throttle up." Three seconds later, Pilot Michael Smith uttered, "Uh oh," at the very moment that all electronic data from the spacecraft was lost.
The public has never heard the inflection of Smith's words, nor the ambient noise in the cabin that underscored them (you can read a transcript here). Despite the existence of evidence of what happened after Challenger's 73 seconds of flight, little of that reality is part of the public's consciousness, understanding, or recollection of the events of January 28, 1986. In part, this can be attributed to a justifiable desire to believe in a merciful outcome: that Christa McAuliffe and the shuttle astronauts all died instantly in what appeared from the ground to be an explosion. But like Smith's instinctive interjection, telltale signs exist that our worst nightmare about the Challenger disaster may have been true. It was very likely that the mid-air blast was not strong enough to kill the crew - and that at least some of the seven astronauts were terrifyingly aware of the impending fate.
On July 28, 1986, Dr. Joseph P. Kerwin, director of Life Sciences at the Johnson Space Center, submitted his report on the cause of death of the Challenger astronauts. The crew module was found that March in 100 feet of water, about 18 miles from the launch site in a location coded "contact 67." While references to the crew were stricken from the report, details about the condition of the module provide many clues about the fate of the astronauts. Kerwin wrote that the cause of the crew's death was inconclusive, but that the force of the initial explosion was too weak to have caused death or even serious injury. This was a direct contradiction to NASA's standard line about the crew's fate, that they were vaporized in the explosion and suffered no further.
If the astronauts were not killed by the blast, then how long did they survive? Challenger as a whole was destroyed at 48,000 feet, but the crew module continued its flight upward for 25 more seconds (to 65,000 feet) before pitching straight down and falling into the Atlantic Ocean.
Evidence that at least some of the crew survived included the recovered personal egress air packs, or PEAPs, designed to provide oxygen to the crew in case they had to ditch the craft in a ground emergency. (NASA had no protocol for in-flight shuttle emergencies in 1986.) Each pack contained several minutes of breathing air, but the tanks had to be opened manually. Salvagers recovered four PEAPs; three of them had been opened. The one belonging to Michael Smith was mounted behind his seat, so it's likely another crewmember had leaned forward to activate it.
Kerwin and his experts theorized that the loss of cabin pressure inside the module could have knocked out the crew within a matter of seconds, but damage from the 200-mph impact made determining the rate of depressurization impossible. The air from the PEAPs would not be enough to keep the crew conscious during a rapid drop in pressure. But a rapid drop in pressure would likely have ripped up the middeck floor, which did not occur. A slow or gradual drop in pressure would keep the crew conscious much longer, and the impact at the bottom of that tumble was harsher on the crew's bodies than any car or plane crash would have been.
In either scenario, it is likely that some - if not all - of the crew were awake and coherent after the disintegration of Challenger, and were conscious long enough to feel the module pitch its nose straight down, to see the blue sky in the cockpit window rotate away in favor of the continent below, and to experience a weightless free fall toward the ocean that lasted a full two minutes and 55 seconds. It is a horrifying scenario so extreme that it's unlikely that even 25 more years will be enough to contemplate it objectively.
For now, many still choose to believe that the men and women aboard the Challenger didn't survive the explosion and were unaware that their loved ones on the ground were watching them descend in a plume of smoke to their deaths. Perhaps that belief holds some truth. Or perhaps, it simply serves to bring some peace to the earthbound souls left in the wake of the Challenger's loss.