Boeing Starliner's historic 1st astronaut launch delayed by Atlas V rocket issue

 A large white rocket sits vertical on a launch pad at night.
A large white rocket sits vertical on a launch pad at night.

CAPE CANAVERAL — Starliner will wait at least four more days for its first crewed launch.

Boeing's new commercial spacecraft, Starliner, waved off its first launch attempt late tonight (May 6) due to a problem with an "oxygen relief valve on the Centaur Stage on the Atlas V," NASA posted on X. Atlas V, the flight's rocket manufactured by United Launch Alliance, has flown missions since 2002 with a 100 percent success rate, but this is its first mission with astronauts.

"The engineering team has evaluated the vehicle is not in a configuration where we can proceed with flight today," an official in Mission Control said in a callout broadcast on NASA Television roughly two hours and one minute before the scheduled launch at 10:34 p.m. EDT (0024 GMT May 7).

Friday (May 10) is not the earliest possible launch target, according to NASA. When Starliner flies, you can watch the event here at Space.com, via NASA Television.

Related: Boeing's Starliner is a 'big piece of America's overall strategy for access to low Earth orbit,' astronaut says

a large white rocket sits vertical on a launch pad at night
a large white rocket sits vertical on a launch pad at night

Once it goes to space, Starliner will carry its first astronaut crew to the International Space Station: Barry "Butch" Wilmore and Suni Williams. They are both former U.S. Navy test pilots as well as veteran International Space Station long-duration astronauts; their new Starliner mission is expected to spend about a week at the orbiting complex.

When Wilmore and Williams fly to space, they will be the first crew to do so from Cape Canaveral Space Force Station since Apollo 7 in 1968. They will also be the first humans to fly to space aboard an Atlas rocket since Gordon Cooper did so on Mercury-Atlas 9 in 1963.

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NASA aims to have Starliner up and running for operational missions next year to meet its longstanding goal of sending two different spacecraft aloft from U.S. soil. The agency's other commercial crew vendor, SpaceX, has been sending crews to the ISS since its first test launch in 2020.

Space.com will provide further updates on the situation when NASA, Boeing or ULA issue them.

Editor's note: This story was updated at 2 a.m. EDT on May 7 with news of the new target launch date of May 10.