Can private-sector space business be profitable, or is it just an exciting way for billionaires to live out their fantasies?

The next frontier of space travel is coming.

On Friday (Nov. 20), NASA awarded a work order to Elon Musk’s private space firm, SpaceX, to transport astronauts to the International Space Station (ISS). Boeing received a similar order for a manned flight back in May. The missions will take place on SpaceX’s Crew Dragon and Boeing’s CST-100 Starliner spacecrafts.

The space agency has not determined which company will deploy first, but the contracts specify launches in late 2017, provided they meet all the necessary certifications and Congress allocates enough funding for the missions.

This will represent the first time private space companies transport US astronauts into space—the US has relied on Russia to ferry astronauts to and from the ISS after the discontinuation of its shuttle program in 2011. NASA said the SpaceX and Boeing flights will cost less per seat than Russia’s Soyuz capsules, which cost $70 million per seat.

But if funding from Congress is not enough to cover the contracts, the flights will be delayed and the agency will have to continue hitching rides on Russian spacecrafts. NASA has not specified the cost of the SpaceX and Boeing contracts.

“When Crew Dragon takes NASA astronauts to the space station in 2017, they will be riding in one of the safest, most reliable spacecraft ever flown,” Gwynne Shotwell, SpaceX’s president and chief operating officer, said in a statement.

SpaceX grounded its Falcon 9 rockets in June after an unmanned rocket exploded minutes after its launch. An initial assessment said the cause was a faulty steel strut.