Mariner 6 and 7
Mariner 6 and Mariner 7 were two unmanned NASA robotic spacecraft that completed the first dual mission to Mars in 1969 as part of NASA's wider Mariner program. Both spacecraft encountered the Red Planet about 3,400 km from its surface in a span of a week (July 31 - August 5, 1969), which nearly coincided with the conclusion of the successful Apollo 11 mission to the Moon
How to install add-ons? Find out here.