The spacecraft disintegrated 46,000 feet (14 km) above the Atlantic Ocean, off the coast of Cape Canaveral, Florida, at 16:39:13 UTC (11:39:13 a.m. EST, local time at the launch site).

The collapse of the ET's internal structures and the rotation of the SRB that followed propelled the shuttle stack, traveling at a speed of Mach 1.92, into a direction that allowed aerodynamic forces to tear the orbiter apart.

Test data since 1977 demonstrated a potentially catastrophic flaw in the SRBs' O-rings, but neither NASA nor SRB manufacturer Morton Thiokol had addressed this known defect.

As a result of this disaster, NASA established the Office of Safety, Reliability, and Quality Assurance, and arranged for deployment of commercial satellites from expendable launch vehicles rather than from a crewed orbiter.

[3]: 48  The O-rings were required to contain the hot, high-pressure gases produced by the burning solid propellant and allowed for the SRBs to be rated for crewed missions.

[3]: 126 Evaluations of the proposed SRB design in the early 1970s and field joint testing showed that the wide tolerances between the mated parts allowed the O-rings to be extruded from their seats rather than compressed.

The two payload specialists were Gregory Jarvis, who was assigned to conduct research for the Hughes Aircraft Company, and Christa McAuliffe, who flew as part of the Teacher in Space Project.

[3]: 10–13 The primary mission of the Challenger crew was to use an Inertial Upper Stage (IUS) to deploy a Tracking and Data Relay Satellite (TDRS), named TDRS-B, that would have been part of a constellation to enable constant communication with orbiting spacecraft.

[6]: 105–106  During this discussion, Lawrence Mulloy, the NASA SRB project manager,[6]: 3  said that he did not accept the analysis behind this decision, and demanded to know if Morton Thiokol expected him to wait until April for warmer temperatures.

[3]: 107–108 When the teleconference prepared to hold a recess to allow for private discussion amongst Morton Thiokol management, Allan J. McDonald, Morton Thiokol's Director of the Space Shuttle SRM Project who was sitting at the KSC end of the call,[6]: 110  reminded his colleagues in Utah to examine the interaction between delays in the primary O-rings sealing relative to the ability of the secondary O-rings to provide redundant backup, believing this would add enough to the engineering analysis to get Mulloy to stop accusing the engineers of using inconclusive evidence to try and delay the launch.

[13] Rocco Petrone, the head of Rockwell's space transportation division, and his team determined that the potential damage from ice made the mission unsafe to fly.

Arnold Aldrich consulted with engineers at KSC and the Johnson Space Center (JSC) who advised him that ice did not threaten the safety of the orbiter, and he decided to proceed with the launch.

[14] The high aerodynamic forces and wind shear likely broke the unintentional aluminum oxide seal that had replaced eroded O-rings, allowing the flame to burn through the joint.

As it traveled at Mach 1.92, Challenger took aerodynamic forces it was not designed to withstand and broke into several large pieces: a wing, the (still firing) main engines, the crew cabin and hypergolic fuel leaking from the ruptured reaction control system were among the parts identified exiting the vapor cloud.

[14][3]: 21  Both SRBs survived the breakup of the shuttle stack and continued flying, now unguided by the attitude and trajectory control of their mothership, until their flight termination systems were activated at T+110.

"[14] In Mission Control, flight director Jay Greene ordered that contingency procedures be put into effect,[14] which included locking the doors, shutting down telephone communications, and freezing computer terminals to collect data from them.

[18]: 245–247 While analyzing the wreckage, investigators discovered that several electrical system switches on Smith's right-hand panel had been moved from their usual launch positions.

Later tests established that neither the force of the explosion nor the impact with the ocean could have moved them, indicating that Smith made the switch changes, presumably in a futile attempt to restore electrical power to the cockpit after the crew cabin detached from the rest of the orbiter.

[33] On April 29, 1986, the astronauts' remains were transferred on a C-141 Starlifter aircraft from Kennedy Space Center to the military mortuary at Dover Air Force Base in Delaware.

During the ceremony, an Air Force band sang "God Bless America" as NASA T-38 Talon jets flew directly over the scene in the traditional missing-man formation.

[47][48] In the rescheduled State of the Union address on February 4, Reagan mentioned the deceased Challenger crew members and modified his remarks about the X-ray experiment as "launched and lost".

[3]: iii–iv The commission held hearings that discussed the NASA accident investigation, the Space Shuttle program, and the Morton Thiokol recommendation to launch despite O-ring safety issues.

[3]: 71  The report was critical of NASA and Morton Thiokol, and emphasized that both organizations had overlooked evidence that indicated the potential danger with the SRB field joints.

In 2004, President George W. Bush conferred posthumous Congressional Space Medals of Honor to all 14 crew members killed in the Challenger and Columbia accidents.

[77] The "Forever Remembered" exhibit at the Kennedy Space Center Visitor Complex opened in July 2015 and includes a display of a 12-foot (3.7 m) section of Challenger's recovered fuselage.

[91] Onizuka had included a soccer ball with his personal effects that was recovered and later flown to the International Space Station aboard Soyuz Expedition 49 by American astronaut Shane Kimbrough.

McConnell's book was criticized for arguing for a conspiracy involving NASA Administrator Fletcher awarding the contract to Morton Thiokol because it was from his home state of Utah.

[6]: 591–592 [97] Also in 1996, Claus Jensen published No Downlink: A Dramatic Narrative About the Challenger Accident and Our Time that primarily discusses the development of rocketry prior to the disaster, and was criticized for its reliance on secondary sources with little original research conducted for the book.

[6]: 592 [98][99] In 2009, Allan McDonald published his memoir written with space historian James Hansen, Truth, Lies, and O-Rings: Inside the Space Shuttle Challenger Disaster, which focuses on his personal involvement in the launch, disaster, investigation, and return to flight, and is critical of NASA and Morton Thiokol leadership for agreeing to launch Challenger despite engineers' warnings about the O-rings.

[105] A film directed by Nathan VonMinden, The Challenger Disaster, was released on January 25, 2019, depicts fictional characters participating in the decision process to launch.