Phobos 2

Phobos 2 was the last space probe designed by the Soviet Union. It was designed to explore the moons of Mars, Phobos and Deimos. It was launched on 12 July 1988, and entered orbit on 29 January 1989. Phobos 2 operated nominally throughout its cruise and Mars orbital insertion phase on 29 January 1989, gathering data on the Sun, interplanetary medium, Mars, and Phobos. Phobos 2 investigated the Mars surface and atmosphere and returned 37 images of Phobos with a resolution of up to 40 meters. Shortly before the final phase of the mission, during which the spacecraft was to approach within 50 m of Phobos's surface and release two landers (one, a mobile hopper, the other, a stationary platform) contact with Phobos 2 was lost. The mission ended when the spacecraft signal failed to be reacquired on 27 March 1989. The cause of the failure was determined to be a malfunction of the on-board computer, and subsequent loss of orientation and power.