The Challenger disaster grounded the space shuttle fleet for nearly three years, exposed deep flaws in NASA's leadership, and prompted significant changes to the agency's safety oversight and decision-making culture.

The Columbia disaster exposed fatal flaws in NASA's shuttle program

On Feb. 1, 2003, Space Shuttle Columbia broke apart during reentry, killing all seven astronauts aboard. The tragedy revealed long-ignored safety warnings, leading NASA to ground the shuttle fleet and overhaul its safety culture.

The Challenger disaster delayed the launch of the Hubble Space Telescope

The 1986 explosion of the space shuttle shortly after liftoff killed seven crew members and grounded NASA's space fleet. Scientists used the downtime to refine ground control software and upgrade telescope instrument sensitivity, but maintaining the telescope's clean room storage cost NASA approximately $6M per month.

The Challenger disaster ended NASA's plan to fly ordinary Americans in space

The explosion of the Challenger halted NASA's civilian spaceflight ambitions for decades, including plans to send teachers, journalists, artists, and other nonastronauts into orbit—an effort aimed at building public support that quietly disappeared after the 1986 disaster.

The Columbia disaster contributed to the end of the Space Shuttle program and NASA's reliance on commercial partners such as SpaceX and Boeing to transport astronauts and cargo.

Watch the Challenger disaster, which killed all seven astronauts aboard, unfold live.

Major milestones of the Space Shuttle program's 135 missions included the launches of the Hubble Space Telescope and the Chandra X-ray Observatory, and the first American woman and African-American astronauts in space.

President Reagan postponed the State of the Union after Challenger

In his Oval Office address delivered the night of the disaster, President Ronald Reagan spoke directly to the nation about the loss of Challenger and its crew, postponing that evening's scheduled State of the Union to address the tragedy.

Listen to the five-part podcast series that reconstructs how Challenger failed

The "American Scandal" podcast devotes a five-part series to Challenger, tracing the engineering warnings, internal pressure to launch, the moment of the explosion, and the long aftermath that reshaped NASA's safety culture.

Watch the Challenger disaster unfold in real time

On January 28, 1986, Space Shuttle Challenger broke apart just 73 seconds after liftoff. This live CNN broadcast captures the tragedy as it happened—second by second—showing the shock and confusion of one of NASA's darkest moments.

The night before the disaster, not everyone signed the Challenger's launch authorization form

Allan McDonald, director of the booster rocket program at NASA contractor Morton Thiokol, refused to sign, believing ice on the spacecraft could damage the orbiter's heat tiles and that cold temperatures could cause O-ring failure. He later testified that management had overruled objections from engineers.

Although it drew inspiration from spaceplane concepts of the 1920s, the Space Shuttle program began to take shape after the Space Race, as the US sought to establish a space station and a reusable transportation system for astronauts and satellites.

The Challenger disaster led NASA to create an independent safety office

In response to the Challenger accident, NASA established the Office of Safety, Reliability, and Quality Assurance—now known as the Office of Safety and Mission Assurance—to strengthen oversight, elevate safety concerns, and mitigate managerial pressure on technical decisions.

Explore what Challenger was supposed to do on its mission

STS-51L's planned seven-day mission included deploying satellites, studying Comet Halley, conducting fluid dynamics experiments, and broadcasting live lessons from orbit—routine scientific and educational tasks that were never carried out after the shuttle was lost shortly after launch.

About 2.5 million American students watched the Challenger disaster live

Because of the publicity of the Teacher in Space program, millions of students viewed Challenger's liftoff in school classrooms—turning the explosion into a shared national traumatic experience marked by shock, silence, and grief.

Richard Feynman exposed NASA's safety failures on the Rogers Commission

The Nobel Laureate served on the Rogers Commission investigating Challenger, famously demonstrating O-ring failure with ice water and eventually criticizing NASA's culture of risk normalization and management pressure in the final report.

View a timeline of NASA's Space Shuttle program, which saw five reusable orbiters take a total of 355 astronauts across a combined distance of almost six trips to the sun.

The Teacher in Space program was launched in 1984 to highlight spaceflight in US classrooms

Announced by President Ronald Reagan, the program drew more than 11,000 teacher applicants nationwide. Christa McAuliffe was selected to fly on STS-51L, with plans to teach live lessons from orbit before the Challenger disaster ended the mission.

Space tourism opportunities have been explored since the end of the Apollo era

In the 1970s, Rockwell International, a NASA contractor, and others investigated manufacturing passenger modules that could fit into the Space Shuttle's payload bay. NASA also opened spaceflights to nongovernment professionals, but many such programs were ended after the Challenger disaster, which killed the first Teacher in Space participant.

Engineers warned Challenger could fail, but were overruled

Engineer Bob Ebeling and four of his colleagues presented data to NASA officials and managers at NASA contractor Morton Thiokol the night before the launch about how cold temperatures could cause O-ring failure. Ebeling claims to have told his wife then that, "[Challenger is] going to blow up."

View a 3D visualization of how space shuttles were built and launched into orbit from NASA's Kennedy Space Center.

Watch the lessons Christa McAuliffe was supposed to teach aboard Challenger

After the Challenger disaster prevented McAuliffe from teaching in orbit, educators-turned-astronauts Joe Acaba and Ricky Arnold filmed her planned science demonstrations aboard the International Space Station during the 2017-18 school year.

Low temperatures led to the equipment failure that caused the Challenger disaster

The polymer chains that make up an O-ring give it the ability to quickly deform and fill in gaps to seal fluids, including the hot gases from the Challenger's rocket boosters. Cold weather on the day of launch stiffened the O-rings, reducing their flexibility and sealing properties.

Big Bird was almost included on the Challenger mission

As part of NASA's early outreach ideas tied to the Teacher in Space program, Sesame Street's Big Bird was briefly considered for a Challenger flight, but the plan was dropped because the oversized costume could not fit safely inside the shuttle.

Faulty wiring and flammable materials caused a fire in the Apollo 1 command module

During a launch rehearsal test on Jan. 27, 1967, the fire took the lives of astronauts Gus Grissom, Ed White, and Roger Chaffee. The tragedy led to improvements to CM construction and the development of a single-piece hatch for escapes.

Aboard Challenger, Christa McAuliffe would have been the first teacher in space

The social studies teacher from Concord, New Hampshire, was selected from over 11,000 applicants to NASA's Teacher in Space program. Had the disaster not ended the mission, McAuliffe planned to teach lessons and conduct microgravity experiments in space.

In honor of scientific exploration, all five launched space shuttles were named after ships that traveled the oceans, but a campaign from 'Star Trek' fans led to the shuttle prototype being named Enterprise.

In 2022, a piece of Challenger was discovered on the ocean floor

While searching for World War II wreckage near Cape Canaveral, Florida, for a documentary, divers discovered debris on the seafloor that NASA later confirmed to be a piece of Space Shuttle Challenger wreckage. The piece is at least 15-by-15 feet in size and partially buried under sand.

Only 34% of Americans supported the Apollo program in 1967

After a fire killed three astronauts on the launchpad of Apollo 1, the public became ambivalent about funding the multibillion-dollar program until the successful moon landing in 1969. The landers alone cost $388M, while each spacesuit cost $100,000.

Explore the interior and exterior of the Atlantis and Endeavour space shuttles, including their flight decks, cargo bays, and other compartments.

During the Space Shuttle program, NASA's Shuttle Carrier Aircraft—two specially modified Boeing 747s—transported space shuttles between landing sites and launch facilities.

Take a 360-degree tour of Discovery with Kathryn Sullivan and Charles Bolden, who flew together on the space shuttle during its deployment of the Hubble Space Telescope. (VR device-compatible)

Evidence suggests some of the Challenger's crew may have been alive after the explosion

Recovery of the intact crew cabin and later analysis of flight data led investigators to conclude the astronauts likely survived the initial breakup and remained alive during the roughly two-minute descent before the cabin struck the ocean.

Watch a firsthand account of Hubble's first service mission to repair its faulty mirror

Hubble senior project scientist David Leckrone recalls initial public ridicule over the microscopic manufacturing error that put NASA's reputation at stake. In this behind-the-scenes interview, he breaks down the innovative fix deployed by space shuttle astronauts during Hubble's first servicing mission.

The commander of the Challenger mission began his career as a mechanic in the Air Force

Lt. Col. Dick Scobee began his career as an Air Force aircraft mechanic, later becoming a Vietnam combat pilot, test pilot at Edwards Air Force Base, and ultimately the commander of Challenger's STS-51L mission.

In 2021 US dollars, space shuttles cost $65,400 per kilogram, making them the most expensive spacecraft for payloads greater than 20,000 kilograms.

The 1978 prediction of the Kessler syndrome popularized the risks of space trash

A paper published by NASA scientists Don Kessler and Burton Cour-Palais described a scenario where the density of objects in orbit becomes so high that collisions between them create a cascading effect of runaway debris, preventing future space travel. The risks were confirmed from returned telescope parts showing debris impacts.

Judith Resnik was the second American woman to fly in space

A PhD in electrical engineering, Judith "Judy" Resnik flew aboard Space Shuttle Discovery in 1984, becoming the second American woman in space, and later served as a mission specialist on Challenger's STS-51L mission.

Overcoming industry skeptics, SpaceX provides low-cost, high-publicity spaceflights

From recovering and reusing rocket components to launching a mannequin and Tesla into orbit to the tune of David Bowie's "Starman," Elon Musk drove public interest and government contracts to his company as he transformed space launches into spectacles.