.....Mariner 10 was the seventh successful launch in the Mariner spacecraft series, and the first to use the gravitational pull of one planet (Venus) to reach another (Mercury). Instruments on board the spacecraft were designed to measure the atmospheric, surface, and physical characteristics of Mercury and Venus. Experiments included television photography, magnetic field, plasma, infrared radiometry, ultraviolet spectroscopy, and radio science detectors. An experimental X-band, high-frequency transmitter was flown for the first time on the spacecraft.

.....On November 3, 1973, Mariner 10 was placed in a parking orbit after launch for approximately 25 minutes, then placed in orbit around the Sun en route to Venus. The orbit direction around the Sun was opposite to that of the Earth. Mariner 10 flew past Venus on February 5, 1974, at a distance of 4,200 kilometers (2,610 miles). More than 4,000 photos of Venus revealed a nearly