Human Spaceflight Programs

NASA's campaign to return humans to the Moon — and eventually establish a sustainable presence for long-duration science and as a stepping stone to Mars. Named after Apollo's twin sister in Greek mythology, Artemis will land the first woman and first person of color on the lunar surface.

The program uses the Space Launch System (SLS), the most powerful rocket ever built, paired with the Orion spacecraft for deep space crew transport. Artemis I (2022) was an uncrewed test flight that sent Orion around the Moon for 25 days. Artemis II (April 2026) is the first crewed mission — a 10-day lunar flyby carrying four astronauts farther from Earth than any human has ever traveled, breaking Apollo 13's distance record at 252,756 miles.

Future missions will dock with the Gateway lunar space station and use SpaceX's Starship HLS lander to reach the surface near the Moon's south pole, where permanently shadowed craters may hold water ice critical for sustaining a human presence.

The world's first reusable spacecraft — a winged orbiter that launched like a rocket and landed like a glider. Over 30 years and 135 missions, the Space Transportation System (STS) built the International Space Station, deployed the Hubble Space Telescope, carried satellites to orbit, and conducted thousands of scientific experiments.

Five orbiters flew operational missions: Columbia, Challenger, Discovery, Atlantis, and Endeavour. The program achieved remarkable feats — satellite repair in orbit, construction of the largest structure ever built in space, and flights carrying up to 8 crew members. The shuttle's versatile 60-foot payload bay could carry 50,000 pounds to low Earth orbit.

The program was marked by two devastating tragedies: Challenger broke apart 73 seconds after launch in January 1986, and Columbia disintegrated during re-entry in February 2003. Both accidents killed all seven crew members aboard and led to fundamental changes in NASA's safety culture. The final shuttle mission, STS-135, flew in July 2011.

America's first space station — a converted Saturn V upper stage that served as an orbiting laboratory for 171 days of crewed operations. Skylab proved that humans could live and work effectively in space for extended periods, paving the way for the ISS decades later.

Three crews of three astronauts each visited the station, conducting over 300 scientific experiments in solar astronomy, Earth observation, biomedical research, and materials science. The station's Apollo Telescope Mount produced unprecedented observations of the Sun, including detailed studies of solar flares and coronal holes.

Skylab's launch was nearly a disaster — a micrometeoroid shield tore away during ascent, taking one solar panel with it and jamming the other. The first crew performed a daring repair spacewalk, deploying a parasol sunshade and freeing the stuck panel, saving the station. Skylab re-entered Earth's atmosphere in July 1979, scattering debris across Western Australia.

The program that landed humans on the Moon. Born from President Kennedy's 1961 challenge to reach the lunar surface before the end of the decade, Apollo became humanity's greatest exploration achievement. Between 1969 and 1972, twelve astronauts walked on the Moon across six successful landing missions.

Apollo pioneered technologies that defined spaceflight for generations: lunar orbit rendezvous, the command/service module and lunar module architecture, the mighty Saturn V rocket — still the most powerful rocket ever successfully flown — and the navigation computers that helped birth the modern computing age. The program returned 842 pounds of lunar samples that revolutionized our understanding of the Moon's origin.

The program endured tragedy with the Apollo 1 fire that killed astronauts Grissom, White, and Chaffee during a launch pad test, and triumph with the miraculous rescue of Apollo 13's crew after an oxygen tank explosion 200,000 miles from Earth. Apollo-Soyuz in 1975 marked the first international crewed spaceflight, docking American and Soviet spacecraft in orbit.

The bridge between Mercury and Apollo — ten crewed missions in 20 months that developed and proved every technique needed to reach the Moon. Named for the twin constellation because it carried two astronauts, Gemini was NASA's crash course in the skills Apollo would need: spacewalking, orbital rendezvous, docking, and long-duration spaceflight.

Gemini 4 featured America's first spacewalk by Ed White, who spent 23 minutes floating outside his capsule over the Pacific. Gemini 6A and 7 achieved the first orbital rendezvous, flying within one foot of each other. Gemini 8, commanded by Neil Armstrong, performed the first docking with another spacecraft — then nearly ended in disaster when a stuck thruster sent the capsule into a violent spin.

The program flew at a breakneck pace unmatched in spaceflight history. In just two years, Gemini mastered every capability Apollo needed, trained the astronauts who would walk on the Moon, and pushed mission durations from hours to nearly 14 days — proving humans could survive a lunar round trip. It was the most efficient learning program in NASA's history.

Where it all began. Project Mercury was America's first human spaceflight program — a response to the Soviet Union's early space achievements that sought to answer the most fundamental question: can humans survive in space? The Mercury Seven astronauts became the nation's first space heroes, household names who embodied the courage and ambition of an era.

Alan Shepard became the first American in space on May 5, 1961, with a 15-minute suborbital flight aboard Freedom 7. Nine months later, John Glenn orbited Earth three times in Friendship 7, becoming a national icon. The program's final mission, Mercury-Atlas 9, kept Gordon Cooper in orbit for over 34 hours — proving the human body could function in weightlessness far longer than initially feared.

Mercury's capsules were tiny — barely large enough for a single astronaut with no room to move. The spacecraft were so cramped that the astronauts said they didn't climb in, they "put it on." Yet these 3,000-pound capsules, sitting atop modified ballistic missiles, launched a spacefaring nation and set the stage for everything that followed.