From the first satellite to telescopes that look into the distant past. Explore 15 selected milestones—and the details behind them.
15 milestones · oldest first
The Soviet Union launched the first artificial satellite into Earth orbit. A small spacecraft became a turning point in global exploration.
The first satellite preceded the first human spaceflight by less than four years.
The United States’ new civilian space agency began work, building on the National Advisory Committee for Aeronautics.
NASA’s remit includes aeronautics: research into flight within Earth’s atmosphere, as well as beyond it.
Soviet cosmonaut Yuri Gagarin became the first human in space during the Vostok 1 mission.
Gagarin’s flight lasted 108 minutes. He ejected from the returning capsule and landed by parachute.
Tereshkova launched aboard Vostok 6, becoming the first woman to travel into space.
Her mission completed 48 orbits of Earth over nearly three days.
Alexei Leonov left Voskhod 2 to become the first person to conduct a spacewalk.
Leaving a spacecraft created a new engineering challenge: the suit had to function as a personal pressurized environment.
Frank Borman, Jim Lovell and Bill Anders became the first humans to orbit the Moon.
During the mission, Anders photographed the famous color Earthrise image above the lunar horizon.
The lunar module Eagle landed with Neil Armstrong and Buzz Aldrin aboard. Michael Collins remained in lunar orbit.
The landing occurred on July 20 UTC. Armstrong’s first step followed on July 21 UTC—still July 20 in the eastern United States.
NASA’s Viking 1 made the first successful U.S. landing on Mars and returned photographs from the surface.
Viking 1 touched down seven years to the day after Apollo 11’s lunar landing.
Voyager 1 launched toward Jupiter and Saturn, beginning a voyage that would eventually take it into interstellar space.
The spacecraft carries a Golden Record of sounds and images representing Earth. Voyager 2 carries one, too.
Ride became the first American woman in space as a mission specialist aboard STS-7.
Her work included helping develop and operate the Shuttle’s robotic arm.
Space Shuttle Discovery carried the Hubble Space Telescope into orbit, opening a new chapter in astronomy.
Astronauts later serviced Hubble, repairing equipment and improving its scientific instruments.
Jemison became the first African American woman in space aboard Endeavour’s STS-47 mission.
A physician and engineer, she worked on a research mission involving life sciences and materials science.
Demo-2 carried Bob Behnken and Doug Hurley toward the International Space Station in a test of SpaceX’s crew transportation system.
The mission tested the system from launch through docking, departure and return to Earth.
NASA’s rover arrived at a Martian crater with evidence of an ancient lake and delta, to investigate the planet’s past.
Its samples preserve clues to Mars’s geological and environmental history, for possible future study on Earth.
The James Webb Space Telescope launched aboard an Ariane 5, beginning its journey toward an observing orbit around the Sun–Earth L2 region.
Its segmented mirror and five-layer sunshield were folded for launch and deployed in space.
A selected timeline, not a complete history. Dates identify the event described. When a milestone crosses calendar days in different time zones, the note explains the distinction.