Mars mainly phyllosilicates and other minerals known from Mars, point toward an origin of Phobos from material ejected by an impact on Mars that reaccreted in Martian orbit, similar to the prevailing theory for the origin of Earth's moon. Although the VNIR spectra of the moons of Mars resemble those of outer-belt asteroids, the thermal infrared spectra of Phobos are reported to be inconsistent with chondrites of any class. Mars may have moons smaller than in diameter, and a dust ring is predicted to exist between Phobos and Deimos. Dozens of crewless spacecraft, including orbiters, landers, and rovers, have been sent
Mars One before arrival at Mars) and a lander (see "Human Lander" below). In 2012, Mars One speculated that the Transit Living Module could potentially be designed and built by Thales Alenia Space. A concept study was produced by Lockheed Martin for a demonstration lander based on the 2008 "Phoenix" lander. In December 2013 Mars One awarded a contract to Surrey Satellite Technology for a study of the satellite technology required to provide 24/7 communication between Earth and the Mars base. Mars One proposed at least two satellites, one in areostationary orbit above Mars and a second at the Earth – Sun