Watch the Challenger disaster unfold in real time

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

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.

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 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 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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

Watch an animated, step-by-step reconstruction of the Chernobyl explosion

This video shows how a 1986 safety test at Chernobyl spiraled out of control—leading to a massive rise in temperatures, an explosion and reactor meltdown that produced the largest civilian nuclear disaster in history.

Watch one of the greatest live TV shots ever

While James Burke was filming the 1978 docuseries "Connections" at the site of a rocket launch, he pulled off a perfectly-timed gesture without use of a green screen. Some say its the greatest live shot ever in TV history.

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.

9/11 was the first global disaster watched in real time across the world

As the first plane struck at 8:46 a.m. ET, CNN's live feed broadcast images worldwide within minutes. An estimated 2 billion people watched the collapse of the Twin Towers live.

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)

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.

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

Relive the Apollo 11 moon landing minute by minute

This interactive project lets you experience Apollo 11 in real time—listening to exchanges between the astronauts and NASA's Mission Control as they guided humanity's first journey to the lunar surface and safely home.

View a timeline of the Chernobyl disaster

The 1986 Chernobyl meltdown, caused by a combination of poor safety design and human error, is the worst nuclear accident in history. At least three dozen people died in the direct aftermath, and experts believe thousands suffered premature cancer deaths from radiation exposure.

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.

Watch a 1957 news report on the Sputnik launch

This 1957 news report captures the shock and uncertainty that followed the launch of Sputnik, showing how the first artificial satellite immediately altered global politics, military planning, and public perceptions of technological power.

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.

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.

Watch an American news report of the Chernobyl disaster

Americans first heard about the Chernobyl nuclear disaster two days after the event, once abnormal radiation was detected in nearby countries. This forced Soviet officials to acknowledge the catastrophe publicly for the first time a few days after it occurred.

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.

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 gallery of all 135 space shuttle mission patches.

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.

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.

Take a multimedia journey through the thirteen days that nearly ended the world

In October 1962, the Cuban Missile Crisis brought the US and Soviet Union to the brink of nuclear war. This interactive archive from the JFK Library reconstructs those tense days through documents, photos, and secretly recorded conversations from the Kennedy White House.

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.

View a schematic of the space shuttle orbiter, including the layout of the flight deck and mid-deck for astronauts, the cargo bay for payloads, and various support systems, such as avionics equipment and the fuel system.

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.

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.

View 60 years of NASA space exploration

Established in 1958—a year after the Soviet Union launched Sputnik 1—the National Aeronautics and Space Administration has taken humanity into outer space and helped reveal the nature of the universe. Historic moments include the Apollo 11 mission putting humanity on the Moon and construction of the International Space Station.

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.

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

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.

Space trash forced astronauts on the International Space Station to take shelter

An inactive Russian satellite broke up into nearly 200 pieces, prompting astronauts on the space station to take shelter in a docked spacecraft and a capsule that could be used to escape in case of emergency.

In 2012, scientists purposely crashed a Boeing 727 to identify where the safest place to sit is on a plane in order to survive a belly-flop-style impact.

The 'Miracle on the Hudson' showed heroism in the air and changed social media forever

On Jan. 15, 2009, US Airways Flight 1549 lost both engines after hitting birds and was safely landed in the Hudson River. The event was a turning point for Twitter, as a photo and a tweet quickly spread—marking Twitter's rise as a real-time news source.

Watch a livestream of Earth from the International Space Station

The feed is made possible by the SpaceTV-1 camera system, which is live over 20 hours a day. Video replays are shown during routine loss of signal communications with the inter-satellite link relaying the video data.

See a timeline of the space race

This interactive timeline chronicles the space race from its Cold War origins to the moon landing, highlighting key figures, pivotal moments, and rapid technological advancements. It combines archival photos, video, and links to related material.

Gregory Jarvis was an Air Force veteran who flew as a civilian payload specialist on Challenger

A Hughes Aircraft engineer with a background in electrical engineering, payload specialist Gregory Jarvis was assigned to STS-51L to study how fluids and satellite propellants behave in weightlessness during shuttle maneuvers.