Voyage to Venus: Remembering NASA's Magellan Mission, 30 Years OnBy Ben Evans, on August 10th, 2020
Thirty years ago today, on 10 August 1990, a tiny spacecraft arrived at Venus to begin a mission of exploration which would map over 90 percent of its cloud-obscured surface. In doing so, it would reveal tantalizing truths about a planet so similar to Earth in size, yet so different in virtually every other aspect. NASA’s Magellan mission—named for the Portuguese explorer Ferdinand Magellan, who first circumnavigated the globe in the early 16th century—had been launched aboard shuttle Atlantis in May 1989 and required 15 months to reach Venus. It went on to acquire unprecedented Synthetic Aperture Radar (SAR) imagery of craters, volcanoes, flat plains, hills, ridges and other geological features on a world long described as Earth’s “evil twin”. So impressively comprehensive were Magellan’s results that they revealed more about Venus in four short years than had been achieved in centuries of ground-based observation.
Yet Magellan had undergone a complex metamorphosis from the drawing board to launching from Pad 39B at the Kennedy Space Center (KSC) in Florida to orbiting a world so similar to Earth, yet so much a perversion of our blue-and-white paradise. Since the 1960s, it had been recognized that radar could yield crude maps of Venus’ surface, which is hidden from direct view by noxious clouds of sulphuric acid. And it was radar that helped peg the planet’s sidereal “day” at 243 Earth-days and determined its retrograde rotation.
By the end of the 1970s, plans for a Venus Orbiter Imaging Radar (VOIR) had begun in earnest. Had this mission been realized in its original concept, it would have been launched by the Space Shuttle in December 1984, reaching Venus in May 1985 and going on to map around 50 percent of the surface over six months of orbital operations. Unfortunately, VOIR’s hefty price tag caused its expected launch date to slip to no earlier than 1987 and eventually precipitated the program’s cancelation in 1982. (...)
https://www.americaspace.com/2020/08/10/voyage-to-venus-remembering-nasas-magellan-mission-30-years-on/AA
https://www.forum.kosmonauta.net/index.php?topic=3622.msg131701#msg131701