NASA on Wednesday announced it has awarded five more astronaut missions to Elon Musk’s SpaceX, with a contract worth an additional $1.4 billion to the company.

The extra flights fall under NASA’s Commercial Crew program, which delivers astronauts and cargo to and from the International Space Station. SpaceX is currently on its fourth operational human spaceflight for the agency.

SpaceX’s Crew Dragon spacecraft has been competing with Boeing and its Starliner capsule for contracts under Commercial Crew. While both companies have now been awarded nearly $5 billion to develop and launch their respective capsules, SpaceX has won 14 missions and Boeing has garnered six. The latter has yet to launch astronauts with Starliner.

Due in part to the fixed-price nature of NASA’s contracts for the program, Boeing has absorbed $688 million in costs from delays and additional work on the capsule. After successfully completing an uncrewed Starliner flight to the ISS in May, the company now aims to carry astronauts for the first time in February.

The 20 flights awarded to date cover crew missions until 2030 when the ISS is expected to be retired from use.