Phobos 1 Phobos 1 Phobos 1 was an unmanned Russian space probe of the Phobos Program launched from the Baikonour launch facility on 7 July 1988. Its intended mission was to explore Mars and its moons Phobos and Deimos. The mission failed on 2 September 1988 when a computer malfunction caused the end-of-mission order to be transmitted to the spacecraft. At the time of launch it was the heaviest interplanetary spacecraft ever launched, weighing . It was to take an estimated 200 days for the "Phobos 1" space probe to travel from the Earth to Mars. Two mid-course corrections were planned. The
Transit of Phobos from Mars transit of Phobos from Mars usually lasts only thirty seconds or so, due to the moon's very rapid orbital period of about 7.6 hours. Because Phobos orbits close to Mars and in line with its equator, transits of Phobos occur somewhere on Mars on most days of the Martian year. Its orbital inclination is 1.08°, so the latitude of its shadow projected onto the Martian surface shows a seasonal variation, moving from 70.4°S to 70.4°N and back again over the course of a Martian year. Phobos is so close to Mars that it is not visible south of 70.4°S or