science · 29 March 1974 · 50 years ago
In 1974, Mariner 10 took the first close-up pictures of Mercury. It was launched 3 Nov 1973. On its way to Mercury, Mariner 10 made its first flyby of Venus on 5 Feb 1974 and discovered evidence of rotating clouds. The mission required more course corrections than any previous mission and was the first spacecraft to use the gravitational pull of one planet to help it reach another planet. In three flybys past Mercury, it mapped about half of the planet's surface. It found a thin atmosphere and a magnetic field. This craft was also the first to use the solar wind as a means of locomotion; when the probe's thruster fuel ran low, scientists used the solar panels as sails to make course corrections. It ended a series of Mariner missions.
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