Astronaut landing on Mars. Artwork of an astronaut controlling a spacecraft descent onto Mars. A heads up display (HUD) is seen projected onto a window pane. The HUD includes important navigational information to help the landing process. The Martian atmosphere is mostly carbon dioxide and surface temperatures are well below freezing. Martian astronauts will have to breathe their own air supply and wear heated spacesuits on the surface of Mars. Mars is a rocky desert world and has no surface water. The gravity is about one third of that on Earth.