SpaceX founder Elon Musk has famously said he wants to die on Mars—just not on impact. Today, the spaceflight company announced plans to begin sending Red Dragon spacecraft to the red planet by 2018. While the initial flights won’t have humans on board, they would represent a critical first step to putting astronaut boots on Mars.

Planning to send Dragon to Mars as soon as 2018. Red Dragons will inform overall Mars architecture, details to come pic.twitter.com/u4nbVUNCpA — SpaceX (@SpaceX) April 27, 2016

As ambitious as that sounds, SpaceX isn’t the only space exploration hopeful with Mars in its sights. Last week, China also revealed plans to send a spacecraft to Mars in 2020, when (as in 2018) the alignment of Earth and Mars favors an easier interplanetary voyage.

The details for both endeavours are still vague, though the director of the China National Space Administration (CNSA) has hinted that the country’s mission will be considerably complicated.

“The probe is expected to orbit the red planet, land and deploy a rover all in one mission, which is quite difficult to achieve,” CNSA director Xu Dazhe said on April 22, according to Xinhua News Agency. Yet China has successfully done just that at the moon, when its Chang’e 3 spacecraft swung into orbit, landed, and deployed the Jade Rabbit lunar rover in 2013.

Musk is anticipated to discuss his plans for Martian colonization more thoroughly at the International Astronautical Congress in Guadalajara, Mexico, in September. Those plans could include sending humans to Mars at some point in the 2020s, an exploration program that would involve a non-financial collaboration with NASA.

"Among the many exciting things we’re doing with American businesses, we’re particularly excited about an upcoming SpaceX project that would build upon a current ‘no-exchange-of-funds’ agreement we have with the company,” NASA deputy administrator Dava Newman writes today in a blog post.

“In exchange for Martian entry, descent, and landing data from SpaceX, NASA will offer technical support for the firm’s plan to attempt to land an uncrewed Dragon 2 spacecraft on Mars."

Getting a Boost

Launching uncrewed vessels to Mars is the first step in any scheme to eventually park humans there, which Musk said was one of his goals when he founded SpaceX more than a decade ago. Landing large payloads on Mars isn’t exactly easy: Beyond a certain mass for the spacecraft, the planet’s thin atmosphere doesn’t support parachute-style braking during descent.

Early test missions are needed to troubleshoot the technologies that will be used to safely set down hefty loads, including humans—technologies such as the retrorocket-powered skycrane that lowered NASA’s Curiosity rover to the Martian surface in 2012.

For now, it seems SpaceX does plan to use propulsive technologies to deposit the Red Dragons, which will be updated versions of the Dragon 2 spacecraft.

“Dragon 2 is designed to be able to land anywhere in the solar system. Red Dragon Mars mission is the first test flight,” Musk said on Twitter, while noting that Dragon might not be ideal for sending humans to Mars. “Wouldn't be fun for longer journeys. Internal volume ~size of SUV.”

View Images Concept art shows a launch of the Falcon Heavy rocket. Photograph by SpaceX

SpaceX’s plan to deliver the Red Dragon to Mars will probably rely on its powerful Falcon Heavy rocket, which the company says will debut later this year but which has previously been subject to flight delays.

Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, thinks the SpaceX plan is reasonable, noting that the company “has the rocket, the spacecraft, the money, and some technical assistance from NASA.” But, he says, “I expect Falcon Heavy schedule delays are likely, that could easily push it to the 2020 window. I’ll be surprised/impressed if they make 2018.”

There’s also no official word yet on how SpaceX will deal with the challenges of planetary protection, the idea that spacecraft making contact with an alien surface should pose no risk of contaminating that world with Earthly lifeforms. SpaceX has previously said that it will seek NASA’s advice on developing a planetary protection plan for Mars.