Firsts of the Early Space Age: Spacecraft That Opened the Way

Explorer 1 was the first artificial satellite launched by the United States, placed in orbit on January 31, 1958, months after Sputnik 1. Its instruments, designed by James Van Allen, detected a band of charged particles trapped by Earth magnetic field, the discovery behind the Van Allen radiation belts. It stayed in orbit until 1970.

The Mercury spacecraft carried one astronaut at a time on the six crewed flights of Project Mercury between 1961 and 1963. It was a small, cone shaped capsule built by McDonnell Aircraft Corporation that relied heavily on ground control. Alan Shepard flew the first suborbital flight, and John Glenn became the first American to orbit the Earth.

Ranger 7, launched in 1964, was the first fully successful mission of the Ranger program after a long string of failures. It was built to crash into the Moon while sending live television pictures, and it returned thousands of images before impact on July 31, 1964, the closest views of the Moon taken to that time.

The Gemini spacecraft carried two astronauts on ten crewed missions in 1965 and 1966 and was used to learn what Apollo would need: orbital rendezvous and docking with an uncrewed Agena target, spacewalks, and longer flights. It bridged the single seat Mercury capsule and the three seat Apollo Command and Service Module.

Luna 9 was a Soviet spacecraft that made the first soft landing on the Moon on February 3, 1966, after a string of earlier Luna failures. Its television camera sent back the first close up images from the lunar surface and eased fears that a lander might sink into deep dust.

Surveyor 1 became the first American spacecraft to soft land on the Moon, touching down on June 2, 1966, months after Luna 9. It was the first of the Surveyor robotic landers, sent to test landing technology and survey sites ahead of Apollo, and it transmitted thousands of images of the lunar surface.

Mariner 10, launched in 1973, was the first spacecraft to use a planetary gravity assist, flying past Venus to bend its path toward Mercury. It made three flybys of Mercury between 1974 and 1975 and returned the first close up images of its cratered surface. No other spacecraft visited Mercury until NASA MESSENGER more than three decades later.

Venera 13 landed on Venus on March 1, 1982, as part of the Soviet Venera program. It returned the first color photographs of the Venusian surface and survived about two hours in extreme heat and crushing pressure, far longer than planned. Its soil drill and X-ray fluorescence spectrometer analyzed the composition of the rock.