A Boeing Starliner crew launch attempt was canceled shortly before the final countdown

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Two NASA astronauts arrived in the final hours before a long-awaited launch attempt aboard Boeing’s Starliner capsule, the first crewed mission for the new spacecraft.

But the mission was canceled about two hours before the countdown clock reached zero because of a problem with the valve of the Atlas V rocket, a core vehicle built by United Launch Alliance of Alabama that will launch the Starliner capsule into space.

Launch officials don’t yet know when they will make a second attempt to get the Starliner off the ground, though they are targeting it now. No later than May 10.

“Good things are worth the wait, and we’ll get a chance to see the rocket and spacecraft (come off) the pad here soon,” Ken Bowersox, NASA’s associate administrator for space operations, said during a news conference Monday evening. “We still have to collect more data. We don’t have a final plan for you yet, it will come as soon as we can provide it.”

The valve in question is located in the second stage of the Atlas V rocket, or in the upper part of the vehicle attached to the Starliner spacecraft.

Sometimes, the valves can get to a position where they start “buzzing” by opening and closing rapidly, said Tory Bruno, CEO of United Launch Alliance.

Some buzzing is OK, but too much of it can cause the valve to fail, Bruno said. Now engineers need to determine whether the component is open and closed enough to cause concern.

Officials will spend a day assessing the problem and determining whether it is necessary to replace the valve and return the rocket from the launch pad.

Before the valve problem arose, it was the Starliner, which Boeing had designed to compete with it SpaceX’s prolific Crew Dragon capsule – It was scheduled to lift off for its inaugural crewed test run at 10:34 p.m. ET on Monday from Space Force Station Cape Canaveral in Florida.

This mission, called the Crew Flight Test, could be the last major milestone before NASA deems Boeing’s spacecraft ready for routine operations as part of the federal agency’s Commercial Crew Program. The Starliner vehicle will join SpaceX’s Crew Dragon in NASA’s push to collaborate with private industry partners, expanding U.S. options for transporting astronauts to the International Space Station.

The mission crew consists of veteran astronauts Sonny Williams and Butch Wilmore, both of whom have ventured into space on two previous flights aboard NASA’s space shuttle and Russian Soyuz missions.

“They’re checking a lot of systems: life support, manual control,” NASA Administrator Bill Nelson said during a press conference on Friday. “That’s why we put test pilots on board – and of course Butch and Sonny’s CVs are extensive.”

This will be only the sixth maiden flight of a manned spacecraft in US history, Nelson noted: “It started with Mercury, then with Gemini, then with Apollo, then the Space Shuttle, then Dragon (SpaceX) – and now Starliner.”

Williams would also become the first woman ever to join such a mission.

If all goes according to plan after launch, the spacecraft – carrying the astronauts – will separate from the Atlas V rocket after reaching orbit and start running its own engines. The Starliner vehicle will then spend more than 24 hours gradually making its way to the space station.

Williams and Willmore are scheduled to spend about a week aboard the orbiting laboratory, joining the spacecraft Seven astronauts and astronauts Already on board, while the Starliner is still docked outside.

The two will then return home aboard the same Starliner capsule, which is expected to land by parachute at one of several designated locations throughout the southwestern United States.

There’s a lot riding on a smooth test ride. NASA waited half a decade for Starliner to begin crewed launches, and Starliner development has faced years of delays, setbacks, and errors. More broadly, Boeing as a company has been plagued for years by scandals in its aircraft division that have tarnished the longstanding aviation giant’s brand.

“We went through a very rigorous process to get here,” Mark Nappi, vice president and Starliner program manager at Boeing, said of the development process during a news conference on Friday. “The truth is that my confidence comes from going through this process.”

If the crew’s test flight is successful, it could put Boeing in line to begin routine flights to the space station on behalf of NASA.

The US space agency chose Boeing to develop the Starliner — along with SpaceX and its Crew Dragon capsule — in 2014, in the hope that commercial companies could create complementary new means of transporting astronauts to the International Space Station after the space shuttle program is retired in 2011.

SpaceX eventually overtook Boeing at the launch pad, conducting crewed flight testing of its Crew Dragon capsule in May 2020. SpaceX handled most of the Of NASA’s crew transportation needs ever since.