Here the Mariner 10 spacecraft is being assembled prior to its November 1973 launch. During its two-year mission, the
spacecraft transmitted over 12,000 images of Mercury and Venus. The mission ended in March 1975. Mariner 10 is still
orbiting the sun, even though its electronic systems have probably been destroyed by solar radiation.
                                                                             
                                                                              Liftoff

A nighttime lift-off of the Atlas Centaur launch vehicle propelled Mariner 10 on its historic mission to Venus and Mercury.
Launched in November 1973, the mission lasted until March 1975 when the spacecraft was shut down and placed in orbit
about the sun.
                                                                       
                                                                         Two Firsts

This model of Mariner 10 shows the spacecraft as it appeared during flight. The Mariner 10 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. 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.
                                                                           
                                                           Venus/Mercury Mission

Mariner 10, shown in this artist's rendering, was the last in a series of Mariner missions designed to survey other planets in the
solar system. Launched in November 1973, this mission provided new information about Mercury and Venus in the Mariner
program's first dual-planet mission. On February 5, 1974, Mariner 10 made its first flyby of Venus and discovered evidence of
rotating clouds. Beginning in March 1974, Mariner 10's three flybys past Mercury mapped about half of the planet's surface,
during which time a thin atmosphere and a magnetic field were discovered.