UNPILOTED SPACE EXPLORATION - HIGHLIGHTS
Program Name Country Years Launched # Missions Main Achievements or Goal Web Link for More Information
Sputnik USSR 1957 - 1958 9 First artificial satellite in space (1957)
First animal in space (a dog named Laika, 1957)		 more information
Explorer US 1958 4 First US artificial satellite in space (1958)
Discovered Van Allen radiation belts around Earth		 more information
Pioneer US 1958 - 1978 12 Studied/photographed Earth, moon, Jupiter, Saturn, Venus
Pioneer 10 - First to travel through the asteroid belt (late 1972); first to reach Jupiter (1973); first to leave the solar system (1983)
Pioneer 11 - first direct observations of Saturn (1979)		 more information
Luna USSR 1959 - 1976 24 Flew past, struck, orbited, and landed on the moon
Luna 1 - First probe to orbit the sun (1959)
Luna 2 - First probe to strike the moon (1959)
Luna 3 - Sent home first photographs of the dark side of the moon (1959)
Luna 9 - First successful (soft) landing on the moon (1966)
Explored moon's surface with vehicles (1970)
Returned samples of moon's surface to Earth (1970)		 more infomation
Venera USSR 1961 - 1983 16 Venera 4 - Studied composition of Venus's atmosphere (1967)
Venera 7 - First successful landing on another planet (Venus, 1970)
Venera 9 - Sent back first photographs of Venus's surface (1975)
Mapped some of the planet's surface		 more information
Ranger US 1961 - 1965 9 Ranger 4 - Flew toward and struck the moon (1962)
Ranger 7 - Sent home close-up photographs of the moon before hitting the surface (1964)		 more information
Mariner US 1962 - 1973 10 Flew past Venus, Mars, and Mercury
Mariner 2 - First probe to reach Venus (1962)
Mariner 4 - Sent home first close-up pictures of the surface of Mars (1965)
Mariner 9 - First to orbit another planet (Mars, 1971)
Mariner 10 - First probe to reach Mercury (1974)
Studied Venus's atmosphere and high surface temperature		 more information
Zond USSR 1964 - 1970 15 Zond 3 - Sent home photographs of the dark side of the moon (1965)
Zond 5 - Flew around the moon and back to Earth (1968)
Flew past Venus (Zond 1, 1964) and Mars (Zond 2, 1965), but contact lost prior to flybys		 more information
Surveyor US 1966 - 1968 7 Surveyor 1 - Successfully landed on the moon (1966)
Determined that moon's surface could support piloted spacecraft		 more information
Lunar Orbiter US 1966 - 1967 5 Photographed and mapped the moon's surface while orbiting (1966)
Found possible landing sites for Surveyor and Apollo missions		 more information
Mars USSR 1960 - 1973 11 Mars 2 - First lander to strike the surface of Mars (1971)
Mars 3 - First successful (soft) landing on Mars (1971)		 more information
Viking US 1975 2 Landed (1976) and searched for life on Mars (found none)
Discovered ice on Mars
Monitored Martian weather; mapped and photographed surface		 more information
Voyager US 1977 2 Sent home close-up pictures of Jupiter (1979), Saturn (1980), Uranus (1986), and Neptune (1989)
Discovered a total of 22 new moons around these planets
Discovered that Jupiter's Great Red Spot is a giant storm
Discovered active volcanoes on Io, a moon orbiting Jupiter
Determined the composition of Saturn's rings (particles of ice and rock)
Discovered an atmosphere on Triton, one of Neptune's moons		 more information
Vega USSR 1984 2 Examined soil on Venus; found rare rocks
Flew past and took close-up photographs of Halley's comet (1986)		 more information
Sakigake & Suisei Japan 1985 2 Flew past and photographed Halley's comet more information
Giotto Europe 1985 1 Flew past and photographed comets Halley (1986) and Grigg-Skjellerup (1992) more information
Magellan US 1989 1 Mapped the surface of Venus while orbiting (1990-1994) more information
Galileo US & Europe 1989 1 First close-up pictures of an asteroid (Gaspra)
Explored Jupiter's hostile atmosphere (1995)
Took close-up pictures of Jupiter's moons Io, Ganymede, Europa, and Callisto		 more information
Hubble Space Telescope US & Europe 1990 1 Largest optical observatory to orbit the Earth
Took the most-detailed pictures of Mars ever taken from Earth
Found proof of black holes and improved our understanding of quasars
Found evidence that suggests the universe is expanding at an increasing rate
Took the first close-up pictures of Pluto and its moon Charon		 more information
Ulysses US & Europe 1990 1 Explored the regions of space high above the sun's poles (1994-2001)
Studied the sun's magnetic field, solar wind plasma, and galactic cosmic rays		 more information
Yohkoh Japan, US & Britain 1991 1 Studies solar flares and other events on the sun more information