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The first Space Shuttle Disaster was Challenger which was lost during an
explosion as it took off from Cape Canaveral on January 28, 1986, killing all
seven people on board. NASA suspended shuttle flights for two years.
The Space Shuttle Challenger Mission (Flight STS-51L) was the
25th Space Shuttle mission and the 10th launch of the Space
It was launched from Pad 39B at Kennedy Space Center in Florida
at 11:38am EST. This mission was highly publicized because it was the first
time a school teacher was allowed to travel in space. Christa McAuliffe, a high school teacher from New Hampshire was
to be the the first civilian in space. She was selected
The crew of Space Shuttle Challenger consisted of 7 astronauts:
- Francis R. Scobee - Mission Commander
- Michael J. Smith - Pilot
- Gregory B. Jarvis - Payload Specialist 1
Christa McAuliffe - Payload Specialist 2
- Judith A. Resnik - Mission Specialist 1
- Ellison S. Onizuka - Mission Specialist 2
- Ronald E. McNair - Mission Specialist 3
The Challenger cargo included two satellites
in the cargo bay and equipment in the crew compartment for
experiments that would be carried out during the mission. The payloads flown on Space Shuttle Challenger Mission 51-L included:
- Tracking Data Relay
a NASA communications satellite that was to have been placed in a
geosynchronous orbit with the aid of a booster called the Inertial
Upper Stage. The satellite would have supported communications
with the Space Shuttle and up to 23 other spacecraft.
- Spartan satellite that would be deployed into orbit
carrying special instruments for the observation of Halley's
satellite was to have been deployed into low Earth orbit using the
remote manipulator system.
Comet Experiment Deployable, a free-flying module designed to
observe tail and coma of Halleys comet with two ultraviolet
spectrometers and two cameras.
Shuttle Challenger Mission 51 L History
Mission 51-L was originally scheduled for July, 1985. The
astronaut crew were assigned in January 1985, however, the launch
was rescheduled to late November 1985 due to changes in payloads.
The November launch date slipped due to delays.
The launch was
re-scheduled for January 22, however, the date slipped
to January 23, then January
24, due to delays in mission 61-C. Launch was reset for January 25
because of bad weather at the transoceanic abort landing (TAL)
site in Dakar, Senegal. To utilize Casablanca (not equipped for
night landings) as alternate TAL site, T-zero was moved to a
morning lift-off time. The launch was postponed another day when
launch processing was unable to meet the new morning lift-off
time. Prediction of unacceptable weather at the Kennedy Space Center
(KSC) led to the launch being rescheduled for 9:37 a.m. EST,
The launch was delayed 24 hours again when the ground servicing
equipment hatch closing fixture could not be removed from the
orbiter hatch. The fixture was sawed off and an attaching bolt
drilled out before closeout was completed. During the delay, cross
winds exceeded return-to-launch-site limits at KSC's Shuttle
Landing Facility. The launch on January 28 was delayed two hours
when a hardware interface module in the launch processing system,
which monitors the fire detection system, failed during liquid
hydrogen tanking procedures.
After several launch delays, NASA officials overruled the concerns of the
engineers and ordered a lift off on a cold morning,
at 11:38:00 a.m. EST on January 28, 1986 . The
mission ended in tragedy. Challenger disintegrated into a ball of fire. The
accident occurred 73 seconds into flight, at an altitude of 46,000 feet (14, 020
meters) and at about twice the speed of sound.
Cause of the Disaster
The main cause of the explosion was the failure of the
aft joint seal in the right SRB due to the cold weather. A combustion gas leak through the right Solid Rocket Motor aft
field joint initiated at or shortly after ignition eventually
weakened and/or penetrated the External Tank initiating vehicle
structural break-up and loss of the Space Shuttle Challenger during
STS Mission 51-L.
Orbiter Did not explode
Challenger itself did not explode, but various structural failures caused the
orbiter to break apart. Although the Challenger disintegrated almost without
warning, the crew may have briefly been aware that something was wrong. The crew
cabin tore lose from the rest of the shuttle and soared through the air. It
took almost three minutes for the cabin to fall into the Atlantic Ocean, where
it smashed on impact, killing the seven crew members.
Space Shuttle SRB's
A full year before Challenger was launched, a major fault was discovered in the
design of the solid rocket boosters - the SRB's. These 2 immensely powerful
rockets are strapped to the side of the External Tank and accelerate the shuttle
clear of the Earth's atmosphere. 2 minutes after launch, the SRB's release from
the Shuttle, dropping to the ocean and are collected for reuse. The SRB's were
built for NASA by a contractor, Morton Thiokol, Inc.
All shuttle missions were halted while a special commission appointed by
President Reagan determined the cause of the accident and what could be done to
prevent such disasters from happening again.
headed by former secretary of state William Rogers the commission
included former astronaut Neil Armstrong and former test pilot
In June 1986, the commission reported that the accident was caused by a failure
of O rings in the shuttle's right solid rocket booster. These rubber rings
sealed the joint between the two lower segments of the booster. Design flaws in
the joint and unusually cold weather during the launch caused the O rings to
allow hot gases to leak out of the booster through the joint. Flames from within
the booster streamed past the failed seal and quickly expanded the small hole.
The flaming gases then burned a hole in the shuttle's external fuel tank. The
flames also cut away one of the supporting beams that held the booster to the
side of the external tank. The booster tore loose and ruptured the tank. The
propellants from the tank formed a giant fireball as structural failures tore
the vehicle apart.
The commission said NASA's decision to launch the shuttle was flawed. Top level
decision makers had not been informed of problems with the joints and O rings or
the possible damaging effects of cold weather.
The Commission also concluded that there was a serious flaw in the decision making
process leading up to the launch of flight 51-L.
Shuttle designers made several technical modifications, including an improved O
ring design and the addition of a crew bail-out system. Although such a system
would not work in all cases, it could save lives of shuttle crew members in
certain situations. Procedural changes included stricter safety reviews and more
restrictive launching conditions.
Shuttle resumes flight
The entire space shuttle program
was grounded during the commission's investigation and did not
resume flying until shuttle designers made several technical
modifications and NASA management implemented stricter regulations
regarding quality control and safety.
The space shuttle resumed flying on September 29, 1988 with the
launch of the redesigned shuttle Discovery on STS-26 mission.
In 1991, the shuttle
Endeavour joined the fleet to replace the Challenger, again
bringing the number of ships to four.
Did you know?
Space Shuttle Columbia Disaster occurred in 2003 and was the second tragedy.
Barbara Morgan was the backup 'Teacher in Space' for this mission. She flew
her first mission in 2007 on
Space Shuttle Models
Truth, Lies, and O-Rings: Inside the
Space Shuttle Challenger Disaster (Hardcover) by Allan J
McDonald (Author), James R. Hansen (Author)
Space Shuttle Challenger: Ten Journeys into the Unknown by Ben
Challenger Accident: The Tragedy of Space Shuttle Flight 51-L
and its Aftermath (CD-ROM)
STS 51-L Space Shuttle Challenger Crew 11x14 Photo
Space Shuttle Links:
Commission Report on Space Shuttle Challenger ...
Accident: Causes and consequences of the Challenger
STS-51L: NASA Archive:
of the PRESIDENTIAL COMMISSION on the Space Shuttle Challenger Accident:
Space Shuttle Challenger Crew Memorialized on Mars:
BBC ON THIS DAY | 28 | 1986: Seven dead in space shuttle disaster:
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Updated: Saturday 23rd, February, 2013
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