The Boeing Starliner spaceship is set to launch astronauts to the International Space Station on Monday night, ten years after its commission by NASA.

NASA astronauts Barry Wilmore and Sunita Williams will pilot the flight test to the space station, where they will stay for about a week to test the capsule and its subsystems.

The flight will be the final test before NASA can certify Boeing to conduct routine missions to and from the space station for the agency.

If the Boeing flight is successful, it will be the second reliable option for human space flight along with Elon Musk’s SpaceX Dragon capsule. SpaceX has been shuttling NASA astronauts to and from the ISS since 2020.

The Starliner program experienced years of setbacks and delays.

During a 2019 uncrewed test flight, the capsule was on an incorrect trajectory and returned without reaching the ISS.

“Two critical software defects were not detected ahead of flight despite multiple safeguards,” NASA said after the failed test flight. “Ground intervention prevented loss of vehicle in both cases.”

Another launch was postponed in 2021 after a valve problem. An uncrewed capsule reached the ISS in May 2022. But the spacecraft has experienced several problems since then, including the discovery of flammable tape in the cabin and weak parachutes.

Monday’s launch is set for 10:34 p.m. local time at Cape Canaveral Space Force Station in Florida.

“We certainly have some unknowns in this mission, things we expect to learn, being a test mission,” Jim Free, NASA associate administrator, said during an April media teleconference. “We may encounter things we don’t expect.”

Some information for this report came from Agence France-Presse.