Lunar Trailblazer

In 1957, the Soviet Union launched Sputnik 1, the world’s first artificial satellite. This event triggered the Space Race between the USSR and the United States, which culminated with the Apollo Moon landings in 1969. The USSR’s Luna 9 was the first spacecraft to achieve a soft landing on another world (the Moon) and to transmit photographic evidence of this achievement back to Earth.

Lunar exploration by robotic spacecraft began with Ranger 7, which successfully impacted the lunar surface in 1964. Surveyor 5 also made a successful lunar landing later that year. The Soviet Union’s Luna 10 became the first artificial satellite of another world when it entered orbit around the Moon in 1966. The US followed suit with Lunar Orbiter 1 in 1967. These missions returned photography and other data that allowed mapping of nearly all of the lunar surface.

The next phase of exploration was conducted by two Soviet Lunokhod rovers, which were deployed from 1970-73; these were followed by three American Surveyor missions from 1971-75 (Surveyor 6 was lost due to a launch vehicle failure). From 1976-78, four Soviet Vega spacecraft performed flybys and balloon deployments at Venus as part of an international cooperative venture that also included France and Japan (the latter nation’s Suisei/Planet-A and Akatsuki/PLANET-C probes would make similar observations more than three decades later). In addition, two US Pioneer Venus multiprobe vehicles were deployed into orbit around Venus during 1978; one carried out atmospheric studies while the other dropped several small probes into the planet’s thick clouds.

The last unmanned mission to leave Earth orbit for almost 30 years was Voyager 2, which flew past Jupiter in 1979 en route to Saturn; its sister ship Voyager 1 made similar observations of Saturn before continuing on its journey out of our solar system. After making numerous discoveries about these giant planets and their moons (including active volcanoes on Io), Voyagers 1 & 2 both went on to observe Uranus (1986) and Neptune (1989); they are currently experiencing technical issues but are still returning valuable data about conditions at interstellar space beyond our solar system’s heliopause boundary