Phobos 2 ======== Instrument Host Overview ======================== Phobos was a next generation spacecraft after those of the Venera- type, last used in the Vega mission (1984-86). The total weight of the spacecraft was 6,200 kg, of which 3,600 kg was the weight of the propulsion system, which was to be separated from the spacecraft after the most power-consuming maneuvers of the spacecraft were performed in setting up the reference orbit. In accordance with the scientific aims of the mission, the instrumentation may be classified as planetary, plasma and solar. The planetary data of the mission was to result from the exploration of Phobos, the martian surface and atmosphere. Instruments involved to this end (spectrometers, cameras, radiometers, and a neutron detector) were mounted within the spacecraft so that their sensitive elements were oriented in an anti-sunward direction (with the exception of the optical radiation spectrometer (ISO)). The spacecraft was to change its orientation to point the instruments towards Phobos or Mars while in martian orbit. One of the Phobos landers was capable of remaining at the surface for a long time and contained instruments for celestial mechanics experiments, analysis of regolith and for television imaging of landing places. The other lander, called a 'hopper', could jump over the surface to study the composition of the Phobos soil in several places. The plasma part of the programme concentrated on the exploration of the magnetic field and plasma environment of Mars, measurements of the parameters of the interplanetary medium, the Sun and cosmic rays. Platform ======== The Phobos spacecraft instruments were mounted directly to the spacecraft structure; there was no scan platform. References ========== Planetary and Space Sciences, Special issues on Phobos, Volume 39, Issues 1-2, January-February 1991. Sagdeev, R. Z., and Zakharov, A. V., Brief History of the Phobos Mission. Nature, Vol. 341, October 19. 1989. p. 581-584