To Touch The Face Of God

Originally published in the Informanté newspaper on Thursday, 1 February, 2018.

Thirty-one years ago, at 14h42 Eastern Standard Time on 22 January 1986, the Space Shuttle Challenger was due to launch. However, due to delays on the previous mission, the launch was first rescheduled to 24 January, and then 25 January due to weather problems at the Abort Landing Site, before finally it was rescheduled to the 27^th of January 1986. Unfortunately, crosswinds at the launch site did not co-operate, and finally the launch was scheduled for the morning of the 28^th.

The 28^th turned out to be an exceptionally cold morning, with temperatures expected to be close to -1 degrees Celsius, the minimum permitted for a launch.  The Shuttle, however, was not certified to operate at such low temperatures, and one of the sub-contractors, Thiokol, had their engineers organise a teleconference with NASA to discuss the problems that the O-rings (flexible rubber seals, in essence) in particular would face, as they were rated only for down to about 4 degrees Celsius, and would harden in colder temperatures. NASA thought the secondary O-Ring would still seal if the primary one failed, and recommended that the launch proceed. Engineer Bob Ebeling told his wife that night that the Challenger would blow up.

The next morning, engineers found ice on the launch tower, indicating the temperature was far lower than anticipated, at -2.2 to -1.7 degrees Celsius. The coldest launch before had been at 12 degrees. Nevertheless, an ice team was assigned to clear the ice, and the launch was postponed for a few hours. But at 11h38 EST, the launch proceeded. The Solid Rocket Boosters (SRB) ignited, and the vehicle was speeding upwards.

At T+0.678 seconds, dark grey smoke was observed from the right-hand SRB, and continued until T+3.375 seconds. Under the stress of ignition, metal casings bent, and hot gases in excess of 2760 degrees Celsius escaped.  Usually, the O-Rings were flexible enough to form a seal before the gases damaged them too much, but on this morning they were too cold, no longer being elastic and flexible enough to do so. Both O-Rings were vaporised before enough Aluminium oxide sealed the joint they were unable to.

At T+40 seconds, the shuttle reached Mach 1, the speed of sound. For the next 27 seconds, Challenger experienced severe wind shear, stronger than any previous flight. By T+58 seconds, a plume appeared near the attach strut of the right SRB. The wind shear had shattered the oxide seal that formed to replace the vaporised O-ring, allowing a flame to pass through the joint. At T+60 seconds the plume burned through the joint and onto the external liquid hydrogen tank. The pressure in the tank began to drop at T+66 seconds. All still seemed normal to both the crew and flight controllers. 

At T+68 seconds, CAPCOM informed the crew to throttle up, and Commander Dick Scobee confirmed, “Roger, go at throttle up.” This was the last communication from Challenger via radio. At T+72 seconds, the Right SRB pulled away from tank, giving the Shuttle sudden lateral acceleration. Pilot Michael J Smith’s last recorded remark on the flight recorder was ‘Uh-oh.’ At T+73 seconds the aft dome of the liquid hydrogen tank failed, ramming it into the liquid oxygen tank. The right SRB rotated, and struck the intertank structure. The external tank suffered complete structural failure.

A fireball enveloped the whole stack. The launch vehicle broke up 15 kilometres in the air. The SRB’s detached, and were remotely detonated at T+110 seconds. The crew cabin, however, was more robustly constructed. It continued on its course, in a ballistic trajectory, peaking at 20km in the atmosphere. At separation, the force of acceleration in the cabin was 12 to 20 times higher than gravity, but within ten seconds in had slowed down to free fall. The forces were not enough to cause major injury.

At least Pilot Mike Smith was confirmed to be conscious during the next two minutes and 45 seconds, based on switches with level locks that had been moved from launch positions. Three of the four Personal Egress Air Packs had been activated on the flight deck, with the expected oxygen consumption during that time. The cabin hit the ocean surface at roughly 333 km/h, with the impact resulting in deceleration of well over 200 times the force of gravity, far beyond the structural limits of craft or crew survivability, way more than any possible car or even aircraft accident. The crew was torn from their seats, and killed instantly by the impact.

The deaths of Francis R Scobee, Michael J Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis and Christa McAuliffe was watched by millions, including schoolchildren, as Christa McAuliffe was to be the first teacher in space. In the aftermath of the disaster, the Rogers Commission investigated the accident, and found NASA’s organizational culture resulted in the disaster. Richard Feynman, in particular, noted that the estimates of reliability offered by NASA management were wildly unrealistic, differing as much as a thousand fold from those of the actual engineers. "For a successful technology," he remarked, "reality must take precedence over public relations, for nature cannot be fooled."

President Reagan put it best, in his speech following the disaster, which remains one of the most significant of the 20^th century. This is an excerpt from that speech:

“Ladies and Gentlemen, […] today is a day for mourning and remembering. […] We know we share this pain with all of the people of our country. […] Your loved ones were daring and brave, and they had that special grace, that special spirit that says, "Give me a challenge, and I'll meet it with joy." They had a hunger to explore the universe and discover its truths. […] We've grown used to the idea of space, and perhaps we forget that we've only just begun. We're still pioneers. They, the members of the Challenger crew, were pioneers.

And I want to say something to the schoolchildren of America who were watching the live coverage of the shuttle's take-off. I know it is hard to understand, but sometimes painful things like this happen. It's all part of the process of exploration and discovery. It's all part of taking a chance and expanding man's horizons. The future doesn't belong to the fainthearted; it belongs to the brave. The Challenger crew was pulling us into the future, and we'll continue to follow them. […]

The crew of the Space Shuttle Challenger honoured us by the manner in which they lived their lives. We will never forget them as they prepared for their journey and waved goodbye and slipped the surly bonds of earth to touch the face of God.”