The SpaceX Dragon reached the International Space Station (ISS) on Sunday, in a major step toward preparing for a future NASA mission to Mars.

The Dragon delivered a Bigelow Expandable Activity Module (BEAM) to the ISS in its cargo, which will dock to the station and expand out to create a new workspace for scientists, NASA explained in a blog post.

In the future, the BEAM could be used for setting up living quarters on Mars. For a mission to Mars, supplies need to be as compact and efficient as possible. An expandable workspace will provide astronauts with the facilities to undertake research on the red planet, without compromising on rocket space.

“When we’re traveling to Mars or beyond, astronauts need habitats that are both durable and easy to transport and to set up,” NASA said on its blog. “That’s where expandable technology comes in. BEAM is one of the first steps to test expandable structures as a viable alternative to traditional space habitats.”

BEAM will be docked to the ISS for two years to test the viability of the structure on a long term basis. During that time, scientists will be looking for any issues that would need to be rectified before depending on BEAMs for more ambitious missions.

The Dragon is one of SpaceX’s proudest achievements. In 2012, it became the first spacecraft from a private company to deliver goods to the ISS, bringing cargo back to Earth on its return.

SpaceX has big plans for the Dragon. Designed to carry crew members, the Dragon has so far only been used for unmanned missions. SpaceX has plans to work with NASA to refine the Dragon, making it more suitable for manned missions. The first manned flight, according to SpaceX, is expected to take place in two to three years time.