Ten Years After Columbia
A little over half a minute later, alarms went off in the cabin as sensors indicated problems with pressure in the left main tire. A few seconds later, there was a false signal that the gear itself on that side was deployed and locked. After a minute or so, the crew received a call from mission control about the tire-pressure issue. Within a few seconds, the left elevon had lost control authority to maintain the proper pitch and roll rate. At that point, the yaw jets, which usually operated in pulse mode, started to fire continuously in a vain attempt to prevent the vehicle from turning to the left. The crew could have seen the indicator lights for this, and a rapid decrease in the propellant on the gauge, but we’ll never know if they did, because the signal was lost at about that time and mission control had received their last transmission. But the flight control system started annunciating its own master alarm, as actuators started to fail, which wouldn’t have gone unnoticed.
Within a few seconds, the hydraulics themselves failed, and the vehicle was out of control. It started to transition from a controlled glide to a ballistic trajectory, like a misshapen cannonball. What had been a forward-moving aircraft started to corkscrew, something that the commander and pilot couldn’t have failed to observe, both from the unexpectedly changing acceleration and shifting horizon in the windshield. The mission specialists behind them on the flight deck probably realized that things were going south as well. A few seconds later, the cover of the left Orbital Maneuvering System pod was torn off, and the top of the cabin started to overheat.
The acceleration was starting to build up, but the crew did manage to restore the mode of the digital autopilot to auto when it was accidentally changed to manual, a few seconds later. At that point, the reaction control system was out of propellant, having fought as long as it could to keep the vehicle under control. Seeing the loss of hydraulic pressure from the failed actuators, the flight crew attempted to restart the Auxiliary Power Units that drove the pumps, to no avail. It was likely their last conscious act to save themselves.
The left wing was tearing off, shearing the softened and melting aluminum, and the noise within the cabin would have been horrific. The vehicle started to pitch up.
Within another ten or fifteen seconds, attacked by the dynamic pressure from a direction never planned by the vehicle’s designers, the payload-bay doors blew off, exposing the payload bay itself to the brutal force. The hurricane of plasma separated the forebody of the vehicle, with the crew cabin, from the rest.
With all power lost, the cabin went dark other than sunlight and earthlight from the windows, but not silent, and started tumbling. The hull itself was quickly breached, and rapidly started to lose pressure. The crew had never closed the helmets of their flight suits, but it probably didn’t really matter. From either the rapid accelerations or the decompression, unconsciousness likely came very quickly, which is merciful, because the heat started to melt the structure itself, spattering molten metal within.
The fiery cabin, now briefly their airborne coffin, continued its long, thirty-four mile uncontrolled parabolic fall over northern Texas, with the charred remains of its inhabitants, until it came completely apart from the increasing atmospheric pressure forces and all took their own path to the earth. Ironically, and perhaps almost poetically, had it occurred an orbit later (as they had considered earlier that day for weather reasons at the planned landing site in Florida), Johnson Space Center would have been ground zero. The heaviest debris would have rained over the southwest Houston neighborhoods in which they had lived at supersonic speeds, and in which their co-workers continued to live. It might have even hit the Mission Control Center itself, where so many of the fateful, and ultimately fatal decisions had been made.
We will never know what thoughts went through the minds of Columbia’s doomed crew in that last minute in which they were becoming aware of their imminent peril. Perhaps, being the rational pilots and engineers that they were, they were simply focused on trying to save the ship. It could have been something as pragmatic as, “I wish that we’d had a better look at the leading edge of that wing.” What we can know is that they died doing something that they had worked years to be able to do, and they loved it, and thought it important. If we now fear to open up the high frontier because of what happened to them, they will have died in vain.
This article is the prologue of the forthcoming book, titled "Safe Is Not An Option: How Our Futile Obsession With Getting Everyone Back Alive Is Killing Our Future In Space."