On the 28th of January, 1986, the Space Shuttle Challenger launched into a clear blue sky
from the Kennedy Space Centre in Florida.
On board were seven highly-trained astronauts, all of them braced to experience either the
first or second space flight of their lives.
But, just over a minute after take off, Challenger exploded in a massive fireball and a cloud
of debris.
Something catastrophic had gone wrong with the Shuttle… a malfunction that at least
some people on the ground had raised concerns about before the launch even began.
Challenger was the second Space Shuttle to be built by NASA.
The National Aeronautics and Space Administration is the body responsible for the civilian space
program of the United States, as well as for the vast majority of American space-related
research and development.
Early missions into space undertaken by NASA in the 1950s and 1960s made use of vehicles
that were generally disposable – good for a single launch only.
One goal of the Space Shuttle project, which begun in the 1970s, was to develop a reliable,
re-usable vehicle for launches into space.
Challenger was the second shuttle to be built.
Like its predecessor, Columbia, it consisted of a reusable space plane, two reusable boosters,
and a disposable fuel tank.
Only the plane would go into space, with the other components being jettisoned during the
launch process.
Once its mission was complete, the shuttle could glide unaided back down to Earth, to
be refitted and used again in future missions.
Over the course of its lifetime, Challenger completed nine successful missions, and was
responsible for several historic milestones.
It carried the first American woman to enter space in 1983, and the first African-American
to enter space in the same year.
It was used in the first shuttle launch to take place at night, and was used to carry
out the very first in-flight pick-up, repair, and redeployment of an orbiting satellite.
Mission STS-51-L was to be Challenger’s 10th mission, and the 25th mission in the
Space Shuttle program overall.
It had three main objectives: to deploy a small satellite, to observe Halley’s Comet,
and to ferry a high school teacher into space so that she could conduct two lessons from
orbit as part of the Teacher in Space Project – a program designed to inspire students
and teachers, and drive interest in space exploration.
The launch was originally planned for the 23rd of January, 1986… but was pushed back
several times, first because of a delay in the completion of another mission, and then
because of unfavourable weather conditions.
It was eventually decided that the launch would take place on the 28th of January – despite
unusually cold weather the night before, which created an abundance of ice on the launch
pad.
The crew boarded, mission controllers made themselves ready, and at 11:38am, the rocket
boosters fired up and Challenger blasted into the sky on a tail of smoke and fire.
Thousands watched its progress both in-person and on television screens all over the country.
73 seconds after launch, however, disaster struck.
A huge fireball consumed the shuttle, and all communications with it were abruptly lost.
The explosion, which was broadcast live on television, completely dismantled the shuttle.
The two rocket boosters survived, arcing off on an uncontrolled course for several seconds
before Mission Control – worried that they might veer towards a populated area – triggered
their self-destruct sequence, and they too exploded.
As people watched helplessly on television screens and from the launch site, debris rained
down, mostly landing in the Ocean.
For more than quarter of an hour this deadly rain of shuttle parts prevented any kind or
search and rescue effort.
When it finally ended and it was safe to do so, searchers parachuted in and began looking
for the reinforced capsule where the crew had resided during launch.
When the crew capsule was finally found, however, there was no cause for celebration.
All seven of the crew had perished.
It appeared that they had survived the explosion and remained conscious just long enough to
switch on emergency oxygen supplies and toggle switches in an attempt to save themselves…
but there was ultimately nothing they could do to prevent their capsule smashing into
the ground.
The seven astronauts lost in the disaster were Commander Francis Scobee, Pilot Michael
Smith, Mission Specialists Ellison Onizuka, Judith Resnik, and Ronald McNair, Payload
Specialist Gregory Jarvis, and civilian high school teacher Christa McAuliffe, who had
won a national competition to be the teacher to deliver the planned lessons from space.
The evening of the accident, President Ronald Reagan addressed the nation, saying:
“The crew of the space shuttle Challenger honored us by the manner in which they lived
their lives.
We will never forget them, nor the last time we saw them, this morning, as they prepared
for their journey and waved goodbye and ‘slipped the surly bonds of earth’ to ‘touch the
face of God.’”
An investigatory commission was set up to determine the cause of the accident.
It was lead by former Attorney General William Rogers, who was briefed by President Reagan
to investigate sensitively, and at all costs avoid embarrassing NASA.
Rogers was happy to comply with this instruction.
Unfortunately for him, however, at least one of his fellow investigators was not.
Richard Feynman was a well-known, charismatic and somewhat unorthodox theoretical physicist,
who joined the investigatory panel even though he was in the midst of battling cancer at
the time.
Throughout the course of the investigation, Feynman insisted on conducting his own investigatory
activities above and beyond the schedule of the commission, something which very quickly
lead to tension between Feynman and the other investigators.
It is, however, because of Feynman’s fearless insistence on getting to the root of the problem
that many key discoveries were made.
He was helped along the way, of course, by many employees of NASA, and fellow members
of the commission.
In some cases these individuals felt that they could not speak freely without risking
their jobs… and so instead would confide in Feynman indirectly.
In one case a commission member invited Feynman to his house for dinner, and after the meal
proceeded to tell him in great detail about a problem he’d been having with his car:
rubber o-rings in the engine would stiffen in cold weather, leading to leaks.
This coded conversation helped lead Feynman to one of the first and most important discoveries
the commission would make.
It was, indeed, a rubber o-ring that had malfunctioned during the shuttle launch.
The cold weather on the day of the disaster had caused it to stiffen and lose its elasticity,
allowing a gap about the thickness of a credit card to form.
As the shuttle blasted towards space, hot fuel leaked through this gap, igniting and
beginning the explosion that had destroyed Challenger.
Feynman, to the annoyance of some other commission members, demonstrated this during a televised
hearing by dipping a sample rubber o-ring into his glass of ice water, and demonstrating
how, when cold, it did not spring back into shape after pressure was applied – a demonstration
that allowed anyone watching, regardless of their level of scientific knowledge, to grasp
the basic concept behind the loss of the shuttle.
It was also discovered that engineers at the company that manufactured the rocket boosters
had raised concerns about the o-rings, and had in fact recommended that the launch not
go ahead in cold weather.
Their concerns had been ignored – something which was put down to a failure in communication.
Again, Feynman insisted on investigating further.
By talking at length to hundreds of employees, he discovered some serious flaws in the chain
of command and work culture at NASA.
Management, he found, severely underestimated the dangers involved in a shuttle launch,
and had a poor understanding of basic concepts around risk and probability.
This, combined with an intense schedule of rocket launches, had been behind the decision
to launch despite misgivings on the part of engineers who more fully understood the dangers.
The report which the commission eventually published made numerous recommendations, most
of which were fully or partially implemented by NASA.
During a 32-month launch hiatus, the shuttle design was overhauled, new quality control
and safety checks were implemented, and NASA moved to a less intense schedule of launches.
While this did much to reduce risk and make the space program safer…
it would not fully address all safety issues.
The loss of Challenger would not be the last major incident in the history of the space
program.
The astronauts who lost their lives in the disaster were cremated, and their ashes buried
together in Arlington National Cemetery, their final resting place indicated by a bronze
marker bearing images of their faces.
They, and others who have lost their lives in space flight accidents, are remembered
in a Day of Remembrance held by NASA at the end of January each year.
It is a day intended to honour their memories, recall their bravery, and to inspire all those
who now work on the space program to do everything possible to avoid a repeat of the mistakes
that lead to their death.