National Aeronautics and Space Administration

Challenger STS-51L

icon-history

Challenger History

  • Plans Are Set for an Ambitious Year NASA set ambitious goals for the Space Shuttle Program in 1986, with up to 15 planned missions, including the first launch from the West Coast at Vandenberg Air Force Base. Other milestone missions would include the launch of two planetary spacecraft, an astronomy mission to study Halley’s Comet and the launch of the Hubble Space Telescope. STS-51L, scheduled soon after the first mission of the new year, STS-61C, was set to be the 10th for space shuttle Challenger and the 25th in the program.
    Space Shuttle Challenger Launch 
  • Mission Objectives The primary objective of STS-51L was to launch the second Tracking and Data Relay System satellite into orbit. The network of satellites would allow near-continuous communications during subsequent shuttle missions. The satellite would’ve been deployed from the space shuttle on the mission’s first day. On the third day of the mission, the crew would deploy the Spartan-Halley astronomy satellite to observe Halley’s Comet as it made its return to the inner solar system. That satellite would be retrieved two days later.
    Challenger Crew
  • An Opportunity for a Teacher to Make History On Nov. 8, 1984, NASA released the Teacher in Space Announcement of Opportunity, kicking off a nationwide search for a teacher who was interested in participating in a space shuttle mission set to take place in 1986. That mission ended up being STS-51L and the planned Teacher in Space Activities would’ve included two live lessons planned for the mission’s sixth day. The lesson “The Ultimate Field Trip” set out to compare life aboard the space shuttle with life on Earth. The second, “Where We’re Going, Where We’ve Been, Why?” sought to explain the importance of research in space.
    Teacher in Space Project
  • A Five-Person Crew Is Announced On Jan. 29, 1985, NASA announced the five-person crew for the STS-51L mission, including Commander Francis R. “Dick” Scobee, Pilot Michael J. Smith and Mission Specialists Ellison S. Onizuka, Judith A. Resnik and Ronald E. McNair.
    Challenger Crew Professional Photo
  • McAuliffe Is Selected as First Teacher to Go to Space From the more than 10,000 applicants received, NASA selected 10 teacher finalists for interviews and medical screenings at Johnson Space Flight Center. On July 19, New Hampshire middle school teacher Christa McAuliffe was announced as the winner. This marked only the second time NASA had assigned two women to a single mission.
    Christa McAuliffe
  • A Seventh Member Joins the Crew Gregory B. Jarvis was selected as a payload specialist candidate in 1984 and originally assigned to participate in the Hughes Corporation’s satellite deployment on the STS-51D mission in March 1985. After his flight assignment changed several times, NASA finally added him as the final crew member for the STS-51L mission on Oct. 25, 1985.
    Gregory B. Jarvis
  • Challenger Is Prepped for Mission Workers at Kennedy Space Center began preparing Challenger for the STS-51L mission immediately upon its return from the previous mission, STS-61A. On Nov. 11, 1985, crews brought Challenger into the Orbiter Processing Facility to remove the Spacelab module from the payload bay and refurbish the orbiter. On Dec. 9, engineers then installed the Spartan-Halley payload and transported Challenger to the Vehicle Assembly Building to attach it to its external tank and Solid Rocket Boosters.
    KSC Workers Preparing Challenger for Launch
  • Arrival at Launch Pad 39B On Dec. 22, Challenger made its way to Launch Pad 39B. Space shuttle Columbia was simultaneously occupying Launch Pad 39A to await the launch of the STS-61C mission, marking the first time shuttles occupied both pads. The Tracking and Data Relay System satellite arrived at the pad on Jan. 5, 1986, for installation in Challenger’s payload bay.
    Challenger Arrives at Launch Pad 39B
  • Engineers and Astronauts Practice Ahead of Launch On Jan. 8 and 9, Kennedy Space Center engineers conducted the Terminal Countdown Demonstration Test. The astronauts participated in the final stages by climbing aboard Challenger just as they would on launch day. The crew also took part in escape drills and met with the media near the launch pad to answer questions and pose for photos.
    Astronauts Participate in Pre-Flight Training
  • Delayed Launch Date Managers initially targeted Jan. 23 as the launch date but pushed it back to Jan. 26 due to continued delays with the launch of STS-61C. The crew made the trek from Houston to Kennedy Space Center on Jan. 24, but with unfavorable weather predicted for Jan. 26, the launch date moved again to Jan. 27. The crew boarded Challenger for the first launch attempt, but managers scrubbed it, due at first to a mechanical issue and then, due to high winds.
    Challenger Crew Gathers for Press Conference
  • A Cold Launch Day Looms On Jan. 28, 1986, the astronauts once again boarded Challenger after managers cleared the launch despite uncharacteristically cold overnight temperatures. Significant ice covered parts of the launch tower, but managers determined it was not enough of a concern to delay the launch. Private conversations amongst engineers raised concerns about the effects of cold temperatures on O-ring integrity in the Solid Rocket Booster segment joins, but they were dismissed by managers. Challenger lifted off at 11:38 a.m. Eastern.
    Ice on the Launch Tower
  • Fire in the Sky Once Challenger cleared the launch tower, Flight Director Jay H. Greene and his team monitored the mission’s progress from the Mission Control Center at Johnson Space Center. The launch appeared to proceed normally for the first minute, but 73 seconds after liftoff, controllers lost all telemetry from Challenger and saw a fireball on their television screens. The same image was broadcast on television screens in homes and schools across the country, with a stunned nation collectively realizing Challenger and its crew had been lost.
    Space Shuttle Challenger Explosion
  • The President Addresses the Nation In a somber address to the nation on the evening of Jan. 28, President Ronald Reagan remembered and honored the Challenger crew. He closed his address by saying, “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 surly the bonds of earth’ to ‘touch the face of God.’”
    Ronald Reagan Addresses the Nation
  • Investigation President Reagan established a presidential commission chaired by former Secretary of State William P. Rogers to investigate the causes of the accident. The Rogers Commission determined the loss of Challenger was caused by a failure in the joint between the two lower segments of the right Solid Rocket Booster. The specific cause of failure was the destruction of the rubber O-ring seals that intended to prevent hot gases from leaking through the joint during propellant burn. The lack of seal from the O-ring caused combustion gases to leak through the right SRB rear-field joint at or shortly after ignition, eventually weakening the external tank and leading to the structural breakup of the vehicle.
    The Rogers Commission Meets
  • Changes for Future Missions After the Rogers Commission concluded their investigation, they provided many necessary Corrective Actions to address the mechanical, operational and cultural factors that contributed to the mishap so that steps could be taken to return the Shuttle Program to safe flight. These recommendations included design and process modifications, as well as the establishment of the Office of Safety, Reliability and Quality Assurance.
    The Space Shuttle Program Continues
  • The Continuation of the Space Shuttle Program On Sept. 29, 1988, after a 32-month hiatus, an all-veteran astronaut crew returned to flight with the orbiter Discovery and completed a successful four-day mission. The first seven missions after the return to flight launched from Launch Pad 39B, where Challenger made its final liftoff. The memory of the Challenger crew was kept alive through the families of the STS-51L astronauts, who established the Challenger Center for Space Science and Education in 1988. The Challenger Center uses space-themed learning and role-playing to cultivate students’ skills and enhance their knowledge in Science, Technology, Engineering and Math (STEM).
    Students Learning at the Challenger Center
icon-crew-biographies

Crew Biographies

Francis R. (Dick) Scobee Commander View Bio
Michael J. Smith Pilot View Bio
Judith A. Resnik Mission Specialist View Bio
Ronald E. McNair Mission Specialist View Bio
Ellison S. Onizuka Mission Specialist View Bio
Gregory B. Jarvis Payload Specialist View Bio
S. Christa McAuliffe Citizen Observer/Payload Specialist View Bio
Columbia Icon Mission

STS-51L Mission

The SLS-51L flight marked the 25th mission in the Challenger Program and came on the heels of mission STS-61C.

During the six-day mission, crew members Dick Scobee, Michael Smith, Judy Resnik, Ron McNair, Ellison Onizuka, Gregory Jarvis and Christa McAuliffe planned to deploy a large communications satellite and deploy and retrieve an astronomy payload to study Halley’s Comet. The mission was also historic in that crewmember McAuliffe would’ve had the distinction of being the first teacher in space, conducting lessons for schoolchildren from orbit.

Challenger Mission Insignia 

The Challenger STS-51L Mission Insignia

icon-accident-2x

STS-51L Accident

On Jan. 28, 1986, the astronauts boarded Challenger after a scrubbed launch on Jan. 27 due to a mechanical issue, and once resolved, strong winds.

Despite unexpectedly cold overnight temperatures at Kennedy Space Center, managers determined that significant ice accumulation on the launch tower was not enough of a concern to delay the launch. Liftoff took place at 11:38 a.m. Eastern.

For the first minute or so of the mission, the launch appeared to proceed normally, but 73 seconds after liftoff, the Mission Control Center lost all telemetry from Challenger and witnessed a fireball on their television screens, realizing the vehicle had suffered a catastrophic malfunction.

Challenger Accident 

Smoke plumes and debris from Challenger STS-51L seconds after takeoff.

Columbia Icon Investigation

Accident Investigation

Shortly after the disaster, President Reagan established the Presidential Commission on the Space Shuttle Challenger Mishap, otherwise known as the Rogers Commission. Secretary of State William P. Rogers and his fellow commission members investigated the mishap and summarized their findings in a report that detailed the technical causes of the accident, as well as the organizational and cultural factors that led to the decision to launch on Jan. 28.

From a technical standpoint, the consensus of the commission and participating investigative agencies was that the loss of Challenger was directly caused by a failure in the joint between the two lower segments of the right Solid Rocket Booster (SRB). The specific failure was the destruction of the O-ring seals that were designed to prevent hot gases from leaking through the joint during the propellant burn of the rocket motor.

The findings from the Rogers Commission Report concluded that there were severe errors in the decision-making process leading up to the launch, as well. They determined that if there was a better management and safety system in place, concerns about the SRB joint seal would have been taken more seriously and the launch might not have occurred.

The Rogers Commission Report also called out the “Silent Safety Program,” noting that after hours of testimony during the investigation, NASA’s safety staff went unmentioned. Additionally, safety representatives were not part of the Mission Management Team, nor were they included on a teleconference that took place the day of the launch.

The Rogers Commission Report detailed scheduling pressures as another factor. NASA projected an annual rate of 24 shuttle flights by 1990, but it was clear that the goal of two flights a month was overly ambitious. As a result of these scheduling pressures, the Kennedy Space Center workforce was putting in excessive overtime and it became difficult to analyze the data from one flight before the next was scheduled to launch.

Investigation Resources Rogers Commission Report

Rogers Commission Report 
First Appearance of Plume 

First appearance of plume after Challenger's liftoff from lowest Solid Rocket Booster (SRB).

Columbia Icon Lessons Learned

Apollo 13 Lessons Learned

After the Rogers Commission conducted their research into the causes of the mishap, they provided many Corrective Actions and recommendations for future missions.

The commission concluded that the faulty Solid Rocket Motor must be changed through either a redesign of the joint itself or the elimination of the joint through the development of a new design. They also determined that NASA must establish a flight rate consistent with its resources and that all high-criticality items and hazard analyses should be reviewed and indicate items that must be addressed prior to flight.

Additionally, Shuttle Program work should be placed clearly under the program manager’s authority, as opposed to individual centers, and NASA should actively take steps to eliminate the tendency of management isolation at Marshall Space Flight Center.

Finally, the report concluded that NASA should establish an Office of Safety, Reliability and Quality Assurance to be headed by an associate administrator who reports directly to the NASA administrator. This office should be independent of other NASA functional and program responsibilities.

Lessons Learned Resources

Congressional Hearing and Reports 
NASA Report
Selected Congressional Hearings and Reports Read Report
Post-Challenger Evaluation 
National Academies Article
Post-Challenger Evaluation of Space Shuttle Risk Assessment and Management – National Academies of Science’s Aeronautics and Space Engineering Board Read Article
Ice on the Launch Pad 
NASA Presentation
Lessons From Challenger View Presentation
CBS News Video
From the archives: 1986 Space Shuttle Challenger explosion Watch Video
Challenger- CBS News Story
CNN Coverage 
CNN Video
1986: CNN's coverage of the Challenger explosion Watch Video
Ronald Reagan Speech 
Reagan Foundation Video
Challenger: President Reagan's Challenger Disaster Speech Watch Video
Remembering Challenger 
History Video
Remembering the Challenger Disaster Watch Video
ABC News Video
Space Shuttle Challenger Explosion, Teacher Christa McAuliffe Dies Watch Video
Christa McAuliffe News Story
Challenger Icon Memorials and Tributes

Challenger Memorials and Tributes

There are a number of memorials throughout the United States dedicated to Challenger and her crew.

Memorials Nation's Memorial

Memorials Additional Memorials and Museums

Space Shuttle Challenger Memorial 
Space Shuttle Challenger Memorial
Arlington National Cemetary Arlington, Virginia
Learn More about Space Shuttle Challenger Memorial
U.S. Challenger Memorials 
Challenger Memorials Throughout the United States Learn More about Challenger Memorials Throughout the United States
Full Throttle Up 
"Full Throttle Up" Performed by 2023-2024 Kindergarten Class From Judith A. Resnik CLC Watch Video
icon-mission

STS-107 Mission

STS-107 was a 16-day microgravity research mission. The crew had a very successful mission and completed a large variety of research during their mission.

Experiments in the SPACEHAB Research Double Module (RDM) included nine commercial payloads involving 21 separate investigations, four payloads for the European Space Agency with 14 investigations, one payload/investigation for ISS Risk Mitigation, and 18 payloads supporting 23 investigations for NASA's Office of Biological and Physical Research (OBPR).

In the physical sciences, three studies examined the physics of combustion, soot production and fire quenching processes in microgravity. An experiment that compresses granular materials in the absence of gravity furthered understanding of construction techniques. Another experiment evaluated the formation of zeolite crystals, which can speed the chemical reactions that are the basis for chemical processes used in refining, biomedical and other areas. Yet another experiment used pressurized liquid xenon to mimic the behaviors of more complex fluids such as blood flowing through capillaries.

In the area of biological applications, two separate OBPR experiments allowed different types of cell cultures to grow together in weightlessness to elevate their development of enhanced genetic characteristics — one use was to combat prostate cancer, the other to improve crop yield.

Another experiment evaluated the commercial usefulness of plant products grown in space. A third experiment looked at developing a new technique of encapsulating anti-cancer drugs to improve their efficiency.

Other studies focused on changes, due to space flight, in the cardiovascular and musculoskeletal systems; in the systems that sense and respond to gravity; and in the capability of organisms to respond to stress and maintain normal function. NASA also tested a new technology to recycle water prior to installing a device to recycle water permanently aboard the ISS.

In addition, there were a number of experiments with the European Space Agency, Canadian Space Agency, German Space Agency and a university. The U.S. Air Force was conducting a communications experiment. Students from six schools in Australia, China, Israel, Japan, Liechtenstein and the United States were probing the effects of space flight on spiders, silkworms, inorganic crystals, fish, bees and ants, respectively.

There were also experiments in Columbia's payload bay, including three attached to the top of the RDM: the Combined Two-Phase Loop Experiment, Miniature Satellite Threat Reporting System and Star Navigation. There were six payloads/experiments on the Hitchhiker pallet — the Fast Reaction Experiments Enabling Science, Technology, Applications and Research. These six investigations looked outward to the Sun, downward at Earth's atmosphere and inward into the physics of fluid phenomena, as well as tested technology for space communications. Additional secondary payloads included the Shuttle Ionospheric Modification with Pulsed Local Exhaust Experiment and Ram Burn Observation.

During the debris recovery activities, some of the Columbia experiments were found. Scientists have indicated valuable science will still be produced. Much of the scientific data was transmitted to experimenters on the ground during the flight.