A mechanical problem has caused Boeing’s new Starliner capsule’s first crewed flight to be postponed until the end of the week.

On May 6, Starliner was scheduled to launch late on Crew Flight Test (CFT), a roughly 10-day mission that would see two NASA astronauts travel to and from the International Space Station (ISS). The effort was canceled, however, around two hours prior to Monday’s scheduled launch, by mission teams who discovered a malfunctioning “oxygen relief valve” on the top stage of Starliner’s rocket, a United Launch Alliance (ULA) Atlas V.

At first, NASA, ULA, and Boeing were hopeful that the problem might be fixed fast, maybe even in time for Tuesday night’s (May 7) second try at launch. However, the teams declared early on Tuesday morning that CFT will launch no sooner than Friday night, or May 10.

“The delay allows teams to complete data analysis on a pressure regulation valve on the liquid oxygen tank of the Atlas V rocket’s Centaur upper stage and determine whether it is necessary to replace the valve,” NASA officials stated in a Tuesday update.

On Friday, the launch is scheduled for 9 p.m. EDT (0100 GMT on May 11). NASA authorities have announced that there would be an extra backup opportunity on

Still, it’s too soon to say whether Starliner and the Atas V will be prepared for takeoff on Friday or Saturday. The decision to replace the valve, which would need wheeling the rocket off the launch pad and returning to ULA’s assembly site, will determine this.

Afterwards, teams would use “tooling to support the Centaur, and the Starliner on top, and then we’d take off all the pressure and simply remove and replace the valve, pressurize it, remove the tooling, and then we’d be ready to roll back,” according to ULA CEO Tory Bruno during a press conference held on Monday night following the scrub.

He continued, “That procedure takes several days.” In the event that replacing the valve proves to be essential, “it’s unlikely we would be prepared to make another attempt before Sunday.”

Butch Wilmore and Suni Williams from NASA are the two members of the CFT crew. Both astronauts left Starliner after the scrub was declared and returned to the crew quarters at NASA’s Kennedy Space Center, which is located close to Cape Canaveral Space Force Station, according to agency officials.

With its Dragon capsule and Falcon 9 rocket, SpaceX has been doing this since 2020. Founded by Elon Musk, the business has already accomplished seven operational crewed flights for NASA and is currently in the midst of its eighth mission. However, Boeing has yet to send a crew aboard Starliner because to multiple delays in the project’s development.