Moons of Mars formed a large moon. Gravitational interactions between this moon and the outer ring formed Phobos and Deimos. Later, the large moon crashed into Mars, but the two small moons remained in orbit. This theory agrees with the fine-grained surface of the moons and their high porosity. The outer disk would create fine-grained material. While many Martian probes provided images and other data about Phobos and Deimos, only few were dedicated to these satellites and intended to perform a flyby or landing on the surface. Two probes under the Soviet Phobos program were successfully launched in 1988, but neither conducted the
Mars Terahertz Microsatellite Wave Instrument) on board the Jupiter Icy Moons Explorer, which the institute jointly developed with ESA and DLR (German Aerospace Center). Unlike the Japanese Space Agency (JAXA), which is under the jurisdiction of the Ministry of Education, Culture, Sports, Science and Technology, NICT's parent agency is the Ministry of Internal Affairs and Communications (MIC). MIC formally approved the Mars Terahertz Microsatellite in early 2017. The preliminary lander's dimensions are a 50 cm cube, and may have a mass of including propellant. Its landing system is proposed to employ an inflatable aeroshell decelerator, and an airbag. Mars Terahertz Microsatellite The Mars