The Magellan spacecraft, also referred to as the Venus Radar Mapper, was a 1,035-kilogram robotic space probe launched by NASA on May 4, 1989, to map the surface of Venus using Synthetic Aperture Radar and measure the planetary gravity. It was the first interplanetary mission to be launched from the Space Shuttle, the first to use an inertial upper stage booster and was the first spacecraft to test aerobraking as a method for circularizing an ...