Boeing Starliner launch: When is the next launch attempt?

The anticipated launch of the Starliner spacecraft, carrying two astronauts to the International Space Station under the collaboration of Boeing and NASA, experienced a delay on Monday night.

Why was Starliner scrubbed?

Despite the intended departure time of 10:34 p.m. ET on Monday from Cape Canaveral Space Force Station in Florida, launch director of United Launch Alliance (ULA) decided to cancel the launch due to concerns regarding an oxygen relief valve on the Atlas V rocket's second stage. 

"Out of an abundance of caution for the safety of the flight and pad crew, we scrubbed the Crew Flight Test (CFT) launch attempt today due to an observation on a liquid oxygen self-regulating solenoid relief valve on the Centaur upper stage," ULA said in a statement.

GettyImages-2151300652.jpg

CAPE CANAVERAL, FLORIDA, UNITED STATES - MAY 6: The NASA countdown clock is seen ahead of the scheduled launch of NASA's Boeing Starliner spacecraft at the Kennedy Space Center on May 6, 2024 in Cape Canaveral, Florida. NASA astronauts Suni Williams

The scrub came nearly two hours before launch, as a countdown was underway and astronauts Sunita "Suni" Williams and Barry "Butch" Wilmore had arrived at the launch site. Both astronauts safely exited Starliner and returned to crew quarters.

ULA CEO Tory Bruno said the valve was "buzzing" loudly enough that the blue team in the launch tower white room helping the astronauts into the capsule could hear the issue. 

Resolving the valve issue would have involved changing the rocket's fueled state, with the crew onboard violating the flight rules. After the crew was off the rocket and the valve was cycled, the buzzing stopped.

The delay allowed engineering teams to spend Tuesday evaluating the data.

GettyImages-2151300675.jpg

CAPE CANAVERAL, FLORIDA, UNITED STATES - MAY 6: NASA, United Launch Alliance, and Boeing employees hold a press conference to discuss the scrubbed launch of NASA's Boeing Starliner spacecraft at the Kennedy Space Center on May 6, 2024 in Cape Canaver

When is the next launch window?

NASA’s Boeing Crew Flight Test had been targeting Saturday, May 25, as the next opportunity to send the Starliner spacecraft to the International Space Station.

On May 22, NASA, Boeing, and ULA announced they would forego the May 25 launch attempt for NASA’s Boeing Crew Flight Test. The team has been in meetings for two consecutive days, assessing flight rationale, system performance, and redundancy. There is still forward work in these areas, and the next possible launch opportunity is still being discussed.

Following a thorough data review, ULA replaced the pressure regulation valve on the liquid oxygen tank on the Atlas V rocket’s Centaur upper stage.

ULA rolled the rocket, with Boeing’s Starliner spacecraft, back to its Vertical Integration Facility at Cape Canaveral Space Force Station in Florida on Wednesday, May 8, to begin the replacement. 

What's the mission?

According to Boeing, this launch will demonstrate the Starliner's launch-to-landing capabilities and will "prove the team’s readiness to achieve NASA certification and fly long-duration missions for the agency." 

Wilmore and Williams will be part of human research studies on the physiological impacts of space flight. They’ll also be carrying some hardware up for future studies. Because this is Boeing's Crew Flight Test (CFT), researchers will pay extra attention to how all the systems are working. 

When the Starliner eventually launches, it will take Wilmore and Williams about 26 hours to reach the International Space Station (ISS), and then they're going to stay aboard for about a week.

Who is on board? Meet the crew

Astronauts Sunita "Suni" Williams, 58, and Barry "Butch" Wilmore, 61, are both retired Navy captains going to space for the third time. 

Williams spent 322 days on the International Space Station. She was a Navy test pilot and graduated from the U.S. Naval Academy and Florida Tech. 

GettyImages-2151794536.jpg

CAPE CANAVERAL, FLORIDA - MAY 06: NASA’s Boeing Crew Flight Test Commander Butch Wilmore (L) and Pilot Suni Williams walk out of the Operations and Checkout Building on May 06, 2024 in Cape Canaveral, Florida. The astronauts are heading to Boeing’s S

Wilmore piloted space shuttle mission STS-129 and commanded Expedition 42 on the International Space Station.  He was a Navy officer and pilot and graduated from Tennessee Tech and the University of Tennessee. 

As the CFT crew, the astronauts will test out Starliner's capability to certify the spacecraft for future astronaut missions. As former Navy test pilots, both astronauts say it is an honor.

Click here to learn more about the crew. 

How to watch

FOX 35 News will stream the launch live on TV, our FOX 35 News App, on the FOX Local app and on our website's livestream here.

For those who would like to see it in-person, there are several rocket launch viewing venues in Brevard County, according to Visit Space Coast's website, including any of the beaches south of Port Canaveral like Jetty Park, Cocoa Beach and all the way down to the Sebastian Inlet State Park.

FOX Weather contributed to this report.