Two NASA astronauts on Friday completed a six-hour spacewalk outside the International Space Station (ISS) in order to install a new docking door meant for spacecraft built by private companies, including SpaceX and Boeing.

The successful spacewalk occurred a day after a key leader at NASA announced the space agency was looking to hand off control of the ISS to a private company within the next decade.

The astronauts installing the new International Docking Adapter (IDA) were Jeff Williams, the commander of the most recent expedition of NASA astronauts to the ISS, and flight engineer Kate Rubins. The spacewalk was the first for Rubins and the fourth for Williams.

The IDA will allow new capsules built by private space exploration companies to connect to the ISS. With the new entrance, NASA is also effectively ending Russia’s dominance of handling cargo to the ISS – all other entrances to the ISS are controlled by the United States’ historic space rival.

NASA believes that by allowing more commercial access to the ISS, it is preparing the way for the first manned mission to Mars.

“Commercial crew flights from Florida’s Space Coast to the International Space Station will restore America’s human launch capability and increase the time U.S. crews can dedicate to scientific research, which is helping prepare astronauts for deep space missions, including the journey to Mars,” NASA spokesman Mark Garcia said in a statement.

The expansion of NASA’s partnership with private companies does not end with the IDA. NASA Deputy Associate Administrator for Exploration Systems Development Bill Hill announced Thursday that the space agency is planning to hand over control of the ISS to a private company by the mid-2020s.

“Ultimately, our desire is to hand the space station over to either a commercial entity or some other commercial capability so that research can continue in low-Earth orbit,” Hill said at the conference.