Challenger Disaster
by ClearThunder​

It was an unusually frigid morning along the central Florida shores of the Atlantic Ocean when, in the pre-dawn darkness, Francis Scobee, Michael Smith, Ellison Onizuka, Judith Resnick, Ron McNair, and Greg Jarvis, boarded a NASA bus to thundering applause and made the 3.5 mile ride to launch pad 39-B. Among this group was a 38-year old American high school teacher named Christa McAuliffe, who had been chosen out of 11,000 applicants to be the first Teacher in space, and conduct classroom lessons from the orbiter that would be beamed to schools worldwide.

Most people saw it as a valuable use of the shuttle that would inspire young people around the world, and especially America, to look to the skies for their future careers. NASA looked at it as the greatest P.R move since the original seven Mercury astronauts were introduced.

Once strapped in and the hatch sealed, there was little that anyone but the Pilot and Commander could do but go through the tedious pre-launch checklist. McAuliffe, who was in the mid-deck area with her fellow astronauts, could only banter among themselves via the intercom. All were trying to calm Christa down, whose heart was beating "a mile a minute" according to one NASA doctor who was monitoring the sensor data. A natural thing for anyone about to make a trip into outer space. The atmosphere was jovial, to say the least.


Christa McAuliffe

Back at the launch control center, located next to the massive Vehicle Assembly Building (VAB), the mood of NASA managers was less than jovial. There were heated arguments between NASA managers and launch controllers, and lengthy telephone conversations with engineers from Morton-Thiokol, the builder of the solid rocket boosters, and engineers at the Marshall Spaceflight Center in Alabama.

Overnight, temperatures in the launch area dipped as low as 18 degrees. Low enough that it violated the threshold of the operating temperatures of the solid rocker boosters, which the shuttle required in order to lift off the pad and fly through the thick lower atmosphere. Morton Thiokol engineers expressed 'grave concern' that the frigid cold would have an effect on the rubber seals or 'O' rings that divided sections of the solid rocket boosters. But these concerns never made it within earshot of NASA administrator, George Abbey, or Jesse Moore, Associate Administrator for Spaceflight at KSC, who spent most of the morning in a spirited debate that was occasionally moderated by Rocco Patrone, an employee of Rockwell, the builder of the Shuttle. There had already been several launch delays, and NASA officials did not want another.


Icing conditions directly under the Main Engines

In typical government fashion, a pressing desire to get the shuttle into space elicited a 'Go' for launch from Moore, who later testified before congress that he never got word of Morton Thiokol's objections to launch due to the weather. NASA, unwilling to have a delay, proceeded with the countdown.

The fate of the seven astronauts were sealed.

At exactly 11:37:21 am, 900,000 gallons per minute of water were discharged from 'rain birds' located on the pad beneath the shuttle --- to absorb the sound and resulting shockwaves of the engines. At the same time, a 100,000 volt electric current passed below the three nozzles of the main engines of Challenger. The hot gases they emitted, ignited, and the engines roared to life. A few seconds later, the solid rocket boosters ignited. Explosive bolts, which held Challenger to the pad, released their grip. Challenger lifted off at exactly 11:38 am.

Everything was 'nominal' as the shuttle began it's roll maneuver --- designed to orient the shuttle for the correct angle of flight. Within a few seconds, a massive, thundering shockwave --- unlike anything any of the first-time observers had ever experienced ---- shook the ground at the VIP viewing area where Christa McAuliffe's parents, and hundreds of other invited guests and the media were seated. A look of wonderment and awe was seen on the faces of everyone. Cheers erupted. There was applause. Everything looked great... just as it should have been.

But unseen by those at the VIP area, the launch control center nearby, and at Mission Control in Houston, was a pillar of flame that had erupted from one of the boosters .... a section that was isolated by an O-ring that had been subjected to below-freezing temperatures overnight, and had been the topic of those heated arguments that got lost between Thiokol engineers, the Marshall Spaceflight Center, and launch control at KSC.


Searing hot, the plume of hot gas penetrated the large external fuel tank which held more than a half-million gallons of propellant. As Challenger passed through the sound barrier, about 65 seconds into the launch, the order to increase the main engine power was given. Eight seconds later, with no apparent warning or reason, there was a massive explosion so violent that Challenger actually separated from the fuel tank and the solid boosters and disintegrated from aerodynamic forces it was subjected to when it was thrown clear of the explosion.

The crowd in the VIP area were stunned. They kept waiting to see if the shuttle would fly out of the tremendous fireball. Perhaps a booster exploded when they separated, some thought. But NASA engineers knew that wasn't the case. Both solid boosters became dislodged from Challenger and kept burning --- flying off in different directions. It was way too early for that to happen. Then, a few seconds later, debris could be seen falling to the ocean. The shuttle would not --- to the naked eye --- fly out of that fireball. Instead, debris was falling everywhere, and NASA officials quickly escorted the families of the astronauts, including the McAuliffe's, away from the VIP area and the media.


Christa McAuliffe's parents react to the Explosion
NASA officials quickly whisked them away moments after this photo

As is customary during NASA flight disasters, all the doors to Mission Control in Houston (who takes over control of all shuttle flights once it leaves the pad) were locked. Drapes that hung in the media viewing area were closed. Rescue teams were dispatched. NASA and Air Force jets, who were patrolling the skies around the 'range' --- the path of travel, began hovering around the area where Challenger's fuel tanks had exploded, looking for any signs that a part of the shuttle, perhaps even the section that held the astronauts, hoping that it had somehow remained intact. Long range cameras, located 525 feet high atop the roof of the VAB spotted large pieces of debris crashing into the ocean over 17 miles away. Helicopters immediately were launched in hopes of finding survivors.

But there were none to find. They were still strapped into their couches on the ocean floor.

The investigation into the tragedy was begun before the bodies were even located or discovered.

Congressional hearings were held. As families .... as the nation, and as the world mourned, a bureaucratic blame game was being waged. In the end, heads rolled. George Abbey was demoted. Jesse Moore, who gave the final 'Go' for launch eventually 'retired.' Others, rather than be subject to public outrage and humiliation, either resigned or retired. In the end, it was all blamed on mismanagement and poor communications between designers, engineers, and administrators.

So typical of government bureaucracy.

There was also a cover up. NASA administrators had told the victims families, and the public, that their loved ones, most likely, died instantly. Perhaps it was to give the families of the astronauts comfort. But it wasn't true. They did not die instantly. Divers who recovered the remains saw that the entire section of the shuttle that comprised the mid-deck and flight deck --- the forward section of the shuttle where the astronauts were seated, had indeed remained intact. In pressurized spacesuits, and with their visors closed, the astronauts would have survived the explosion. But their 65,000 foot plunge to the ocean, making impact at over 200 miles an hour, killed them instantly. One can only and eerily imagine the chaos and horror that those astronauts were experiencing as the ocean grew closer and closer, knowing that impact meant certain, instant death. Though few in number, there are some scientists and medical experts who doubt that the crew remained conscious from the tremendous G-forces they were subject to when their ship was hurled away and broke apart.

But Story Musgrave, a scientist, engineer, and surgeon -- a veteran of several shuttle missions, knew what NASA knew. And when he retired ---- free of the secrecy oaths and threats of punishment, Musgrave spoke out, vociferously, about the tragedy. Speaking to the press, he was succinct.

"They were alive when they hit that water." He said, with authoritative conviction. "They were alive! And that's a fact!" Musgrave gave several interviews in the years' since his retirement, reiterating not only his belief, but that there was "hard evidence" to back up his assertion that the Challenger astronauts died when they hit the water. In an interview with a local Orlando TV station --- 3:35 into the clip ---- Dr. Musgrave again reasserts his position.

NASA, to this day, still refutes it.

Months after the tragedy, as congressional hearings continued, NASA, in a bid to perhaps show the public that they were taking steps to ensure that astronauts would have a means of escape, developed a launch escape system, including parachutes, that could be used as a last resort in the event of a similar tragedy at a similar altitude and in similar circumstances. It seemed odd to many observers that the agency that claimed that the astronauts aboard Challenger perished instantly and publicly said that there was no way that anyone could have survived, would develop an escape system for the exact same eventuality.

Still, NASA had to continue with the space shuttle program once the flaws in the Booster rockets were solved, and new procedures were put into place. And when NASA approved of the changes, the shuttle program was back in the business of flying two and a half years later.

But they were still flying the same machine that had an extraordinate amount of flaws that could cause a disaster at every turn. The Space Shuttle was, and remains, the most complex and dangerous flying machine that had ever been built by man. With over 100,000 moving parts, and the most unorthodox launch and re-entry procedures, the ship was literally a disaster waiting to happen. The three main engines aboard the shuttle, each cranking out over 65,000 horsepower, was not enough to lift the 100 ton orbiter and it's massive cryogenic fuel tank (and it's contents) off the launch pad. Two solid fuel rocket motors had to be incorporated into the array. Once started, they could not be stopped. When they had exhausted their fuel, they would separate from the shuttle and parachute into the ocean, where they would be retrieved, restored and reloaded.

In all, it took 1900 tons of fuel and hardware to get a 100 ton spaceship to an initial altitude of 80 miles.

Danger lurked in every facet of the shuttle. Each solid booster had to ignite exactly 100 milliseconds apart. And if one ignited, and the other didn't -- a possibility --- the shuttle would lift off the pad and do a U-turn right back onto the ground, or in the ocean only a few hundred yards from the launch pad. The holocaust that would ensue not only would instantly kill the crew, but potentially destroy the entire launch site and everything else, for miles around.

The three main engines on (inside) the shuttle were just as dangerous, although not for the same reasons. About as large as a V-8 automobile engine (the exhaust nozzles gave everyone the impression they were much larger), the engines were simply one, large turbo pump that would gulp a ton and a half of liquid hydrogen and liquid oxygen per second. The 'shear pin' that served as the 'axle' for each turbo pump, was a critical component, and if stressed or cracked, would cause an instant explosion. The designers knew this. So did NASA. Yes, the astronauts knew it too.

Still, at the time of the Challenger launch, there was no means of escape for the crew. And in the case of a disaster on the launch pad, nobody would be there to get them out. There simply wouldn't have been enough time. Though there was a wire-basket escape system in place at the pad, it would have been useless in the case of an explosion.

But we're just getting off the ground.

Once launched, even if everything worked perfectly, NASA was faced with another challenge; breaking the sound barrier, or, as space insiders called it, 'Max-Q' --- the point where the shuttle would be subject to the highest dynamic forces on it's superstructure.

Because the solid rocket boosters always burned at full power, the speed of the shuttle had to be reduced as it passed through the sound barrier. Otherwise, the ship would break apart. To prevent this, the main engines had to be 'throttled back' to around 65% of their rated power until the barrier had been broken, and another dangerous phase of launch had passed.

Providing all three main engines worked as planned, eight and a half minutes later, at an altitude of about 80-miles, they would stop. The large external tank would separate and harmlessly burn up re-entering the atmosphere. At this point, the shuttle was in space, although on-board booster engines would fire, raising the ship to a higher orbit of 160 miles, and increasing it's speed to 17,500 miles per hour. Or roughly, five miles per second. Any slower, and the shuttle would slowly fall back towards Earth.

Even orbiting in space, the shuttle was still not out of danger, save for the threat of being hit by space debris or a meteorite. The on-board booster engines posed another great danger unto themselves. They were fueled by hypergolic propellants ---- highly dangerous and corrosive chemicals that exploded on contact with each other. Loaded in separate tanks, the amount needed for each 'burn' was simultaneously pumped into the combustion chamber where they would literally cause a controlled explosion that provided thrust for maneuvering and re-entry. A single mistake --- say, a computer error --- that would cause the propellants to enter the combustion chambers in un-equal amounts, would result in an explosion. And if the computer loaded too much fuel into the staging tanks, the 'burn' would be longer, and the shuttle would simply keep going farther into space until it reached a point where it could not return to earth.

And then, re-entry ... which will be a topic of another tragedy whose anniversary is sadly approaching.

Like the pressure to succeed that contributed to the fatal fire aboard Apollo-1, the desire to maintain a schedule, and the layers of bureaucracy that caused a roadblock of vital communication between management and engineers resulted in the needless loss of life. And once again, seven astronauts were the victim of human error. And until the shuttle program ended 25 years later, NASA continued the fly these vitally necessary but dangerous machines.

The loss of life was not over. But the astronauts who perished on Challenger will never be forgotten.


The Crew of STS-51-L - Challenger
(L-R) Front-Row: Michael J. Smith, Dick Scobee, Ronald McNair;
(back row) Ellison Onizuka, Christa McAuliffe, Gregory Jarvis, Judith Resnik.

On the day of the disaster, the president's State of the Union address was to be given. But the events of the day changed that. President Reagan went on national television and addressed not only the entire nation, but the world as well. It remains one of Reagan's most eloquent and emotionally moving speeches he ever gave.

Let's all remember January 28, 1986.