Apparent retrograde motion notable on Mars which has two natural satellites, Phobos and Deimos. Both moons orbit Mars in an eastward (prograde) direction, however Deimos has an orbital period of 1.23 Martian sidereal days, making it supersynchronous, whereas Phobos has an orbital period of 0.31 Martian sidereal days making it subsynchronous. Consequently, although both moons are travelling in an eastward (prograde) direction, they appear to be travelling in opposite directions when viewed from the surface of Mars due to their orbital periods in relation to the rotational period of the planet. All other planetary bodies in the Solar System also appear to periodically
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