NASA launched the Magellan spacecraft from Space Shuttle Atlantis, the first planetary probe launched from a shuttle. Using synthetic aperture radar to pierce Venus's opaque cloud cover, Magellan eventually mapped 98% of the planet's surface in unprecedented detail, revealing volcanic plains, impact craters, and evidence of a geologically young surface.
Venus's permanent shroud of sulfuric acid clouds had long frustrated astronomers hoping to study its surface. Magellan solved the problem by carrying a radar system that could bounce microwave signals off the ground and reconstruct images regardless of cloud cover, much like ground-penetrating instruments used on Earth.
After a 15-month cruise, Magellan entered Venus orbit in August 1990 and spent over four years mapping the planet in successive passes, eventually covering 98 percent of the surface at resolutions previously unimaginable. Scientists discovered vast volcanic plains, some of the largest lava flows in the solar system, and a surprising scarcity of small impact craters, suggesting the surface had been resurfaced by volcanism within the last several hundred million years.
The mission ended dramatically in October 1994 when engineers deliberately sent Magellan plunging into Venus's atmosphere to gather data on atmospheric density until the spacecraft burned up — a fittingly fiery end for a mission that unveiled the solar system's hottest planet.