55 years ago, on March 27, 1969, an Atlas-Centaur rocket launched from NASA's Kennedy Space Center in Florida, sending Mariner 7 on its way to study Mars. Mariner 7 was the second Mars probe; Mariner 6 launched Feb. 24, 1969, to investigate Mars' equator. Mariner 7 made a close flyby of Mars just five days after Mariner 6. Scientists were able to instruct it to take additional pictures of the south pole, which had piqued their interest during Mariner 6's flyby.
The Mariner program launched 10 missions to explore Mercury, Venus, and Mars through flybys or orbits. These missions proved that interplanetary exploration was workable with small, low-cost spacecraft, laying the groundwork for all the deep space exploration missions that followed.
Image Credit: NASA
