1.) Mariner 10:
Mariner 10 is an American Robotic space probe launched by NASA on November 3, 1973, to fly by the planets Mercury and Venus. It was launched approximately two years after Mariner 9 and was the last spacccraft in the Mariner program. (Mariner 11 and 12 were allocated to the Voyager program and redesignated (Voyager 1 and Voyager 2) respectively. The mission objectives were to measure Mercury's environment, atmosphere, surface, and body characteristics and to make similar investigations of Venus. Secondary objectives were to perform experiments in the interplanetary medium and to obtain experience with a dual-planet gravity assist mission.
Mariner 10 is still orbiting the sun, although it's electronics have been damaged by the sun's radiation. Dave Williams of NASA's National Space Science Data Center said in 2005 that "[Mariner 10] has not been tracked or spotted from Earth since it stopped transmitting. We can only assume it's still orbiting [The Sun], but the only way it would not be orbiting would be if it had been hit by an asteroid or gravitationally perturbed by a close encounter with a large body, the odds of that happening are extremely small so it is assumed to still be in orbit."
Operator: NASA / JPL Mission type: Flyby of: Venus, Mercury Launch date: 1973-11-03 Launch vehicle: Atlas-Centaur Launch site: Space Launch Complex 36ACape Canaveral Air Force Station, Florida Mission duration: Nov 3, 1973 – Mar 24, 1975 (1 year, 4 months, 22 days) Mass: 474 kg (1,040 lb) Power: (solar array) External Links: en.wikipedia.org/wiki/Mariner_10