Mariner 7The unmanned NASA/JPL space probe Mariner 7 makes its closest flyby of planet Mars, coming as close as just over 2100 miles from the Martian surface. Having recently suffered an inexplicable but temporary loss of communications with Earth (later determined to be caused by a leaky on-board battery), Mariner 7’s flight plan is reprogrammed just days out from Mars based on some of the more interesting findings of its sister ship, Mariner 6. The success of the tandem flight to Mars convinces NASA to adopt a similar mission profile for the upcoming Mars ’71 missions, which will send two Mariner orbiters to take up permanent positions around Mars.