STS-51-L was the 25th mission of the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

Space Shuttle program The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. I ...

and the final flight of Space Shuttle ''Challenger''. Planned as the first

Teacher in Space Project The Teacher in Space Project (TISP) was a NASA program announced by Ronald Reagan in 1984 designed to inspire students, honor teachers, and spur interest in mathematics, science, and space exploration. The project would carry teachers into space ...

flight in addition to observing Halley's Comet for six days and performing a routine satellite deployment, the mission never achieved orbit; a structural failure during its ascent phase 73 seconds after launch from Kennedy Space Center Launch Complex 39B on January 28, 1986, killed all seven crew members —Commander Francis R. "Dick" Scobee, Pilot Michael J. Smith, Mission Specialists Ellison S. Onizuka, Judith A. Resnik and

Ronald E. McNair Ronald Erwin McNair (October 21, 1950 – January 28, 1986) was an American NASA astronaut and physicist. He died during the launch of the Space Shuttle ''Challenger'' on mission STS-51-L, in which he was serving as one of three mission sp ...

, and Payload Specialists Gregory B. Jarvis and S. Christa McAuliffe—and destroyed the orbiter. Immediately after the disaster, President Ronald Reagan convened the

Rogers Commission The Rogers Commission Report was written by a Presidential Commission charged with investigating the Space Shuttle ''Challenger'' disaster during its 10th mission, STS-51-L. The report, released and submitted to President Ronald Reagan on Jun ...

to determine the cause of the explosion. The failure of an O-ring seal on the starboard Solid Rocket Booster (SRB) was determined to have caused the shuttle to break up in flight. Space Shuttle flights were suspended while the O-rings and other hazards that could have destroyed the vehicle on following missions were addressed. Shuttle missions resumed in September 1988 with STS-26, launched 32 months after the accident.

Planned mission

The tenth mission for ''Challenger'', STS-51-L, was scheduled to deploy the second in a series of

Tracking and Data Relay Satellite A tracking and data relay satellite (TDRS) is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communications to and fr ...

s ( TDRS-B), carry out the first flight of the "Shuttle Pointed Autonomous Research Tool for Astronomy" (SPARTAN-203) / Halley's Comet Experiment Deployable in order to observe Halley's Comet, and carry out several lessons from space as part of the

and Shuttle Student Involvement Program (SSIP). The flight marked the first American orbital mission to involve in-flight fatalities. It was also the first American human spaceflight mission to launch and fail to reach space; the first such mission in the world had been the

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

Soyuz 18a mission, in which the two crew members had survived. Gregory Jarvis was originally scheduled to fly on the previous shuttle flight ( STS-61-C), but he was reassigned to this flight and replaced by Congressman Clarence W. "Bill" Nelson.

Crew

Backup crew

Crew seating arrangement

Although the crew died in the ''Challenger'' disaster, their seating assignment chart depicts what would have happened if the mission had been performed as planned.

Ascent failure and disaster

During the ascent phase, 73 seconds after liftoff, the vehicle experienced a catastrophic structural failure resulting in the loss of crew and vehicle. The Rogers Commission later determined the cause of the accident to have been the failure of the primary and secondary (backup) O-ring seals on ''Challenger''s right Solid Rocket Booster (SRB). The failure of these seals allowed a flamethrower-like flare to impinge upon one of two aft SRB attach struts, which eventually failed, freeing the booster to pivot about its remaining attachment points. The forward part of the booster cylinder struck the external tank inter-tank area, leading to a structural failure of the Space Shuttle external tank (ET) – the core structural component of the entire stack. A rapid burning of liberated propellants ensued. With the structural "backbone" of the stack compromised and breaking up, the SRBs flew off on their own, as did the orbiter, which rapidly disintegrated due to overwhelming aerodynamic forces. The launch had been approved despite a predicted ambient temperature of , well below the qualification limit of major components such as the SRBs, which had been certified for use only at temperatures above . Evidence found in the remnants of the crew cabin showed that several of the emergency

Personal Egress Air Pack Personal Egress Air Packs, or PEAPs, were devices on board a Space Shuttle that provided crew members with about six minutes of breathable air in the case of a mishap while the vehicle was still on the ground. PEAPs did not provide pressurized a ...

s (PEAPs) carried by the astronauts had been manually activated, suggesting that forces experienced inside the cabin during breakup of the orbiter were not inherently fatal, and that at least three crew members were alive and capable of conscious action for a period following vehicle breakup. "Tracking reported that the vehicle had exploded and impacted the water in an area approximately located at 28.64° north, 80.28° west".

Crew fate

Divers from the located what they believed to be the crew cabin on the ocean floor on March 7, 1986. A dive the following day confirmed that it was the cabin and that the remains of the crew were inside. No official investigation into the ''Challenger'' disaster has determined the cause of death of the astronauts; it is almost certain that the disintegration itself did not kill the entire crew as 3 of the 4 Personal Egress Air Packs (PEAPs) that were recovered had been manually activated. This would only be done during an emergency or loss of cabin pressure. PEAPs do not provide a pressurized air flow and would still have resulted in the astronauts losing consciousness within several seconds. There were media reports alleging that NASA had a tape recording of the crew panicking and on-board conversation following the disintegration during the 2 minute 45 second free fall before hitting the sea east of

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and ...

. This was likely fabricated and no recording exists, as the crew may have been unconscious from loss of cabin pressure and the astronauts did not wear individual voice recorders.

Mission objectives

* Deployment of Tracking Data Relay Satellite-B ( TDRS-B) with an

Inertial Upper Stage The Inertial Upper Stage (IUS), originally designated the Interim Upper Stage, was a two-stage, solid-fueled space launch system developed by Boeing for the United States Air Force beginning in 1976 for raising payloads from low Earth orbit to ...

(IUS) booster * Flight of "Shuttle Pointed Autonomous Research Tool for Astronomy" (SPARTAN-203)/Halley's Comet Experiment Deployable * Fluid Dynamics Experiment (FDE) * Comet Halley Active Monitoring Program (CHAMP) * Phase Partitioning Experiment (PPE) * Three Shuttle Student Involvement Program (SSIP) experiments * Two lessons for the Teacher in Space Project (TISP) * (unofficial) Ronald E. McNair was planning to play the

saxophone The saxophone (often referred to colloquially as the sax) is a type of Single-reed instrument, single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed (mouthpi ...

in space for a track on Jean-Michel Jarre's album ''"Rendez-Vous"''.

Mission insignia

Francis R. "Dick" Scobee asked Kennedy Space Center engineer Ernie Reyes to design the mission patch seen above to represent the mission STS-51-L. In it, ''Challenger'' is depicted launching from Florida and soaring into space to carry out a variety of goals. Among the prescribed duties of the five astronauts and two payload specialists (represented by the seven stars of the

U.S. flag The national flag of the United States of America, often referred to as the ''American flag'' or the ''U.S. flag'', consists of thirteen equal horizontal stripes of red (top and bottom) alternating with white, with a blue rectangle in the c ...

) was observation and photography of Halley's Comet, backdropped against the U.S. flag in the insignia. Surnames of the crew members encircle the scene, with the payload specialists being recognized below. The surname of the first teacher in space, S. Christa McAuliffe, is followed by a symbolic

apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...

References

External links

Report of the Presidential Commission on the Space Shuttle ''Challenger'' Accident

{{Orbital launches in 1986 1986 in spaceflight Space accidents and incidents in the United States Space Shuttle missions Space program fatalities Space Shuttle Challenger disaster Spacecraft launched in 1986 1986 in Florida January 1986 events Rocket launches in 1986