Another short delay for Boeing Starliner, now targeting May 25

NASA and Boeing need more time to make sure a helium leak on its CST-100 Starliner is low enough risk to send humans into space.

So the launch of NASA astronauts Butch Wilmore and Suni Williams has now been pushed to May 25 targeting a 3:09 p.m. liftoff atop a United Launch Alliance Atlas V rocket from Cape Canaveral Space Force Station’s Space Launch Complex 41.

The duo were sitting in the capsule on the pad with about two hours left on the countdown clock on May 6 when a problem with a fluttering valve on the upper stage of the Atlas V forced mission managers to scrub.

After rolling the rocket back to ULA’s Vertical Integration Facility near the pad and switching out the valve, managers found a second issue with a small helium leak on the Starliner’s service module.

The source of the leak was traced to a flange on a reaction control thruster, and teams performed pressure tests that showed the leak was “stable and would not pose a risk at that level during the flight,” according to a NASA press release.

A retargeted May 21 launch had been on the table, but pushing it four days later gives Boeing teams time to work through operational procedures to “ensure the system retains sufficient performance capability and appropriate redundancy during the flight.”

Wilmore and Williams remain in Houston under quarantine.

When it flies, it will be the first human spaceflight for Starliner as Boeing attempts to play catchup to SpaceX’s Crew Dragon as part of NASA’s Commercial Crew Program. If all goes well, Starliner can join Dragon for regular rotational astronaut ferry service to and from the ISS as soon as February 2025.

SpaceX’s fleet of four Crew Dragons has flown 13 missions carrying 50 humans to space since May 2020 and has three more carrying an additional 12 people to space that could fly this year.

___