Boeing's Starliner spacecraft launch delayed by at least four days due to helium leak

The launch of Boeing's Starliner spacecraft has been delayed once again, this time by at least four days, due to ongoing work to resolve concerns about a small helium leak in the capsule's propulsion system. The new launch date is set for May 25, a week from Saturday, at 3:09 p.m. EDT from Pad 41 at Florida's Cape Canaveral Space Force Station.

The mission commander, Barry "Butch" Wilmore, and co-pilot Sunita Williams had initially aimed for a May 6 launch, but the countdown was called off due to trouble with an oxygen pressure relief valve in their Atlas 5 rocket's Centaur upper stage.

The spacecraft had been set for its first piloted test flight earlier this month, but technical issues forced a delay. The unrelated helium leak in the Starliner's propellant pressurization system was noted during the original countdown to launch, prompting a closer inspection.

Helium Leak Investigation

The leak was detected in plumbing making up helium manifold No. 2 inside one of four "doghouse" assemblies spaced around the exterior of the Starliner's service module. Engineers tightened bolts in a flange where the leak was detected, pressurized the lines, and ran tests to determine if the leak was still present. However, tests revealed that the leak was still present.

Despite the leak being stable and within acceptable limits, mission managers are working to ensure that the system retains sufficient performance capability and appropriate redundancy during the flight. As a result, the launch has been rescheduled for May 25, pending additional data reviews and analysis.

Astronaut Preparations

Mission commander Barry "Butch" Wilmore and co-pilot Sunita Williams, both veteran Navy test pilots and astronauts, flew back to the Johnson Space Center in Houston after the May 6 scrub to participate in additional flight simulations. They are expected to return to Florida next week in preparation for the new launch date.

Commercial Crew Program

The Starliner is one of two commercially developed crew ferry ships ordered by NASA in the wake of the shuttle program's retirement in 2011. SpaceX, the other company awarded the contract, has successfully completed several crewed missions to the International Space Station (ISS) using its Crew Dragon spacecraft.

Boeing's Starliner has faced technical glitches and delays, including major software problems during an initial unpiloted test flight in December 2019. However, the upcoming mission is a critical step in demonstrating the spacecraft's capabilities.