The Magellan spacecraft was a 1,035-kilogram (2,282 lb) robotic space probe launched by NASA on May 4, 1989. Its mission objectives were to map the surface of Venus by using synthetic-aperture radar and to measure the planetary gravitational field. The Magellan probe was the first interplanetary mission to be launched from the Space Shuttle, the first one to use the Inertial Upper Stage booster, and the first spacecraft to test aerobraking as a method for circularizing its orbit. Magellan was the fifth successful NASA mission to Venus, and it ended an eleven-year gap in U.S. interplanetary probe launches. Beginning in the late 1970s, scientists advocated for a radar mapping mission to Venus.

Wikipedia: https://en.wikipedia.org/wiki/Magellan_(spacecraft). Related NASA reference: https://science.nasa.gov/mission/magellan/. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).