SpaceX is looking at possible landing sites on Mars for an upcoming unmanned mission and, later manned missions to the surface.

In a presentation at the Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas, SpaceX Spacecraft Manager Paul Wooster said there were four locations currently in the running, reported SpaceNews.

SpaceX is hoping to launch an unmanned mission to Mars as soon as 2018 called Red Dragon, although this may be delayed until 2020, landing in 2021. This stationary lander will carry up to 1 ton of scientific equipment to study the surface, with subsequent missions every two years.

In September 2016, SpaceX CEO Elon Musk said he wanted to then start sending humans to Mars as early as 2024. His ultimate goal, using a futuristic rocket and spacecraft called the Interplanetary Transport System (ITS), is to have a million people living on Mars in 100 years.

These initial Red Dragon missions will not only be important scientifically, but will also lay the groundwork for these future manned missions. To achieve its goal of colonizing Mars, SpaceX wants to find regions that are rich in subsurface ice in addition to being near the equator, where sunlight is more abundant for solar power.

"It’s probably hard to find that along with ice," noted Wooster in the presentation.

^{SpaceX wants to start transporting people to Mars in a decade. SpaceX}

The most promising location for the inaugural Red Dragon at the moment looks to be Arcadia Planitia, which has been studied using high-resolution images from NASA’s Mars Reconnaissance Orbiter (MRO). The area is quite near the equator, but also relatively smooth and devoid of large rocks, making a landing easier.

Three other locations were also being considered – Deuteronilus Mensae, Phlegra Montes, and Utopia Planitia – based on medium-resolution images, but higher quality images revealed that they were quite rocky. SpaceX was open to other suggestions for future missions.

It’s going to be quite a busy year for Mars exploration in 2021, when Red Dragon will be joined by NASA’s 2020 Mars rover and ESA’s ExoMars rover. NASA is currently deciding on the landing site for its rover too, with three locations being considered. ESA is favoring a region called Oxia Planum for its landing.

(H/T: SpaceNews)