Photos: Famous firsts in space On July 20, 1969, the Apollo 11 mission put the first humans on the moon. Neil Armstrong famously commemorated his first steps on the moon by saying, "That's one small step for man, one giant leap for mankind." Hide Caption 1 of 21

Photos: Famous firsts in space Edwin "Buzz" Aldrin, Armstrong's fellow astronaut on Apollo 11, salutes the U.S. flag on the lunar surface. Aldrin followed Armstrong and became the second man to walk on the moon on July 21, 1969. Hide Caption 2 of 21

Photos: Famous firsts in space This is the first photograph of Earth's south polar ice cap. It was taken by the crew of Apollo 17 as the astronauts traveled to the moon in December 1972. Hide Caption 3 of 21

Photos: Famous firsts in space The Soviet Union launched the Space Age and the space race with the successful launch of Sputnik I, the world's first satellite, on October 4, 1957. It orbited the Earth every 98 minutes. Hide Caption 4 of 21

Photos: Famous firsts in space Laika the dog is pictured aboard Sputnik II on November 13, 1957. She was the first animal to orbit the Earth. She did not survive her trip, but the mission provided valuable data that paved the way for the first human in space. Hide Caption 5 of 21

Photos: Famous firsts in space Soviet pilot and cosmonaut Yuri Gagarin made history as the first human to fly into space. On April 12, 1961, Gagarin took off in the Vostok 1, orbited the Earth and parachuted back to firm ground. Hide Caption 6 of 21

Photos: Famous firsts in space Less than a month after Gagarin's trip, astronaut Alan Shepard became the first American to travel into space. On May 5, 1961, Shepard piloted Freedom 7, the first manned Mercury program mission, in a suborbital flight that lasted a little more than 15 minutes. Hide Caption 7 of 21

Photos: Famous firsts in space John Glenn, aboard the Friendship 7, became the first American to orbit the planet on February 20, 1962. He also set a record as the oldest astronaut in space when, at the age of 77, he went on a mission aboard the Space Shuttle Discovery in November 1996. Hide Caption 8 of 21

Photos: Famous firsts in space Valentina Tereshkova, seen here with Gagarin, piloted the Vostok 6 on June 16, 1963, becoming the first woman to fly into space. Hide Caption 9 of 21

Photos: Famous firsts in space Soviet cosmonaut Vladimir Komarov died during his second flight when the Soyuz 1 spacecraft crashed during its return to Earth on April 23, 1967. He was the first human to die during a space mission. Hide Caption 10 of 21

Photos: Famous firsts in space Skylab, the United States' first space station, orbited Earth from 1973 to 1979. The Soviet program had launched their first space station, Salyut, in 1971, and it stayed in space for 15 years. Hide Caption 11 of 21

Photos: Famous firsts in space On July 15, 1975, Cold War adversaries temporarily broke the thaw when the United States and the Soviet Union embarked on their first joint space mission. Russia's Soyuz craft launched seven hours before the U.S. Apollo craft, and the two vehicles linked up 52 hours after Soyuz lifted off. Here, the two crews pose for a portrait. Hide Caption 12 of 21

Photos: Famous firsts in space At left is Alexei Leonov, commander of the Soviet crew of Soyuz 19, shaking hands with Thomas Stafford, commander of the American crew of Apollo 18, on July 17, 1975. This would be the last Apollo mission conducted by NASA. Hide Caption 13 of 21

Photos: Famous firsts in space Gen. Arnaldo Tamayo Mendez, center, looks at a homemade rocket in Havana, Cuba, in 2009. Mendez became the first Latin American, the first person of African descent and the first Cuban to fly in space when he flew aboard the Soviet Soyuz 38 on September 18, 1980. Hide Caption 14 of 21

Photos: Famous firsts in space Taking off on April 12, 1981, Columbia made the first orbital flight of NASA's space shuttle program. Here, crew members John Watts Young, left, and Robert Laurel Crippen hold a model of the orbiter in 1979. Hide Caption 15 of 21

Photos: Famous firsts in space Sally Ride became the first American woman to go into space when she was part of a crew aboard the space shuttle Challenger in June 1983. Hide Caption 16 of 21

Photos: Famous firsts in space Guion "Guy" Bluford was the first African-American to go into space. He was a mission specialist on the space shuttle challenger in 1983. Hide Caption 17 of 21

Photos: Famous firsts in space In February 1984, astronaut Bruce McCandless became the first astronaut to float in space untethered, thanks to a jetpack-like device called the Manned Maneuvering Unit. The units are no longer used, but astronauts now wear a similar backpack device in case of emergency. Hide Caption 18 of 21

Photos: Famous firsts in space Jan Davis and Mark Lee were the first couple to go into space together when the husband and wife were astronauts on the space shuttle Endeavour in 1992. Hide Caption 19 of 21

Photos: Famous firsts in space The private company SpaceX sent an unmanned capsule with supplies to the International Space Station on October 7, 2012. It was the first commercial space mission and the first of a dozen commercial cargo flights under a contract with NASA. Hide Caption 20 of 21