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 One but that accommodating Mars One requirements would require some additional work and that such action was not a part of the current focus of SpaceX. SpaceX has no ongoing contracts with Mars One. The first Mars One cargo mission to Mars is proposed to launch by 2022, followed by a crewed mission in 2024, but without funds, hardware, and without a launcher it is seen as unlikely to happen. A hypothetical crewed interplanetary spacecraft, for which there are no concept design studies, would be assembled in low Earth orbit and comprise two propellant modules: a Transit Living Module (discarded just