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.

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 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.

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 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.

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.

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.

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

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.

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)

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.

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.

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.

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.

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

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.

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

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.

Explore a timeline of the International Space Station National Lab

In 1984, President Ronald Reagan called for establishing a human presence in space, which began with NASA astronaut Bill Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev on November 2, 2000. Humans have continuously occupied the ISS every day since.

Ellison Onizuka was the first Asian American in space

A member of the 1986 Challenger mission crew, Onizuka was also the first Hawaiian in space, having been one of 35 people selected from a pool of 8,000 applicants for astronaut training in 1978.

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.

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

NASA was founded in response to early Soviet space achievements

Although starting behind in the Space Race in 1958, NASA became a global leader in humanity's exploration of space with the Apollo program, which placed astronauts on the moon. Since then, it has been responsible for the construction of multiple telescopes, the International Space Station, and development of the Artemis program to return humans to the Moon before eventually reaching Mars.

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.

John Glenn's Friendship 7 flight finally put the US in orbit in February 1962

After the Soviets took the lead in the space race, John Glenn's three-orbit Friendship 7 mission on February 20, 1962, made him the first American to orbit Earth. This NASA anniversary piece delivers a minute-by-minute account—from launch delays to splashdown and recovery.

The Polaris Dawn program led to the first commercial spacewalk

As part of the Polaris program, this first mission included a crew comprising astronauts and SpaceX engineers, who conducted scientific experiments and cultural outreach, such as raising funds for St. Jude Children's Research Hospital.

Most elements of the International Space Station were installed over two decades

Space shuttles delivered storage carriers, docking compartments, airlocks, solar arrays, and labs, which were assembled in low Earth orbit. The station’s Canadarm2 robotic arm, alongside maneuvering spacewalkers, has assisted with this assembly since its installation in 2001.

The USSR's space program achieved many historic firsts in the Space Race

Soviet scientists launched the first satellite, sent the first human into orbit, and carried out early spacewalks—milestones that gave the USSR a decisive early lead in the Space Race and reshaped global competition in science and technology.

On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first human in space

In 1961, Soviet cosmonaut Yuri Gagarin became the first human to orbit Earth, deepening US fears of falling behind in the space race. Watch archival footage to see why the mission was such a historic turning point.

The space race was a Cold War rivalry between the US and the Soviet Union that culminated in the US landing astronauts on the moon in 1969.

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.

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

In 2001, a $20M ticket officially kicked off space tourism

On that day, American businessman Dennis Tito became the first paying passenger to visit space, spending a week aboard the International Space Station. Since then, space participants have been members of suborbital flights, which do not require intensive training to prepare for.

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.

The Russian Federal Space Agency enabled the first space tourism journey

NASA refused to take Dennis Tito, who had no formal training as an astronaut, up to the International Space Station. Instead, the American engineer and entrepreneur traveled aboard the Soyuz TM-32 mission and described the initial experience of microgravity after engine shut-off as the "most spectacular" part of the flight.

The space race ended with a handshake in orbit in 1975

On July 17, 1975, American and Soviet astronauts docked their spacecraft during the Apollo–Soyuz mission, symbolically ending the space race and marking the first joint spaceflight between Cold War rivals.

Read about every visitor to the International Space Station

The US has sent the most astronauts to the ISS, with 170 visitors, followed by 64 from Russia, 11 from Japan, and nine from Canada. American astronauts Michael E. Lopez-Alegria and Peggy A. Whitson and Russian cosmonauts Yuri Malenchenko and Fyodor Yurchikhin have the most trips, with five each.

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.

Lego's Women of NASA set honors four NASA pioneers: computer scientist Margaret Hamilton, astronaut Sally Ride, astronaut Mae Jemison, and astronomer Nancy Grace Roman.

The Apollo program built US space technology and showcased its Cold War dominance

Beyond landing humans on the moon for the first time, Apollo served to advance rocket engineering and guidance systems through crewed and uncrewed missions. By Apollo 15, the Lunar Roving Vehicle was developed and driven on the moon.

View a gallery of all 135 space shuttle mission patches.

Mae Jemison, the first Black woman in space

Astronaut Mae Jemison describes her journey from space-loving girl in Chicago to astronaut looking down on Chicago and thinking about her younger self in this two-minute video. Physician, engineer, educator, entrepreneur and the first woman of color in the world to go into space, Dr. Jemison was a NASA astronaut for six years.

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.

Mission specialist Ronald McNair was the second African American to fly in space

Growing up in Lake City, South Carolina, McNair described deep self-motivation as key to overcoming struggles in mathematics, having come from a family with no one having a background in mathematics or science. He credited his own curiosity and discipline developed through athletics—especially karate—with helping him build resilience.

The Artemis program to bring humans to the moon for the first time since 1972

Using NASA's next-generation megarocket, the Space Launch System, Artemis I will take an uncrewed spacecraft on a 42-day journey around the moon. Subsequent missions plan to land the first woman on the lunar surface.

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.

Before the first human spaceflight in 1961, scientists sent fruit flies, monkeys, and dogs into space.

NASA has partnered with several private companies to promote commercial space stations

The retirement of the International Space Station in 2030 has led NASA to refocus its efforts on continuing microgravity research through private partnerships, including the support of multiple commercial space stations' design and development.

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.

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.