Spaceflight Simulator Wiki

Deimos is one of the two Martian moons, the other moon being Phobos. It is smaller than Phobos and orbits further away from Mars. The moon's extremely low gravity makes landings easy but more time-consuming. It has a smooth terrain, unlike Phobos' porous terrain.


Deimos's small size and extremely low gravity make any atmosphere impossible to retain.


A section of Deimos' terrain.

The terrain is relatively smooth unlike Phobos. There are some hills on the surface; usually they are very low enough for rockets to not tip over. But, Deimos has very little gravity, thus rockets would tip over very easily. Rockets that are tilted in different angles usually stay like this, then slowly fall down. Deimos' uneven shape makes gravity apply unevenly to rockets near its surface.

Moving on Deimos

  • Driving a rover on Deimos is difficult, because the rocket will probably escape Deimos's gravity and orbit Mars.
  • Unlike most objects in the game, its shape is highly irregular, similar to the real-life Deimos; this can make efforts at orbiting sometimes dangerous.

What to do on Deimos

Deimos has very little gravity, so using it for gravity assists is useless.

It is very easy to do orbit insertion with fuel, because of the little gravity on the surface. RCS thrusters are now enough to get into orbit.

Deimos bases can be built; but because of the small sizes, make sure the bases are small. The maximum number of bases to build on Deimos is 4.

A Mars space station can be built on Deimos. Docking is very easy due to the small size.


  • It is the smallest celestial body in-game.
  • Along with Phobos, it can be used as a place for practicing and experimenting on orbital physics. Here one can also practice docking.
  • Along with other celestial objects, Deimos' velocity can't be changed, thus it can't be de-orbited.
  • If it could be de-orbited, it would take more than 4 million Rocketdyne F-1 engines to de-orbit Deimos under a day.
  • Deimos is slowly backing away from Mars. Eventually in the far future, it would escape Mars's gravitational field and become an asteroid that crosses Mars's orbit.
  • Deimos is so small that you can even form a sphere around it and de-orbit it.
  • It is also the only celestial body to have a size less than 1 kilometer.
  • Phobos and Deimos seem to follow a 4:1 orbital resonance.
  • In real life, Deimos has a sphere of influence but not extending more than 16.4 kilometers.
  • Deimos is named after the Ancient Greek god and personification of dread and terror, and who is also a son of Ares and Aphrodite and the twin brother of Phobos.
  • Like Phobos, it might have been captured by Mars' gravity because of Jupiter; however it may have been captured in a later date at around 3.8–1.5 billion years ago, roughly 200–500 million years later when Phobos is captured.
  • The moon was never attempted to be explored.
  • A future mission to Mars named Martian Moons eXploration (MMX) will visit Mars's moons in 2025.
Sun MercuryVenusEarth (Moon) • Mars (Phobos · Deimos) • Jupiter (Io · Europa · Ganymede · Callisto)
Earth Moon
Mars PhobosDeimos
Jupiter IoEuropaGanymedeCallisto