Another week, another leak for Boeing's Starliner crew capsule

Boeing's CST-100 Starliner capsule will spend a little longer on Earth than planned following the discovery of a leak in one of the spacecraft's reaction control thrusters.

For context, a few weeks' delay is nothing compared to the years it has taken Boeing to reach this point. The first crewed launch had been set for May 6. However, problems with a pressure regulation valve on the liquid oxygen tank of the Atlas V rocket's Centaur upper stage scrubbed the launch.

Managers initially pushed the launch back to no earlier than (NET) May 10, then May 17, following a decision to replace the troublesome valve.

The launch was then delayed to NET May 21 after technicians discovered the helium leak. The schedule has since slipped further, and the current launch date and time is NET 3:09 pm EDT on May 25.

The leak itself is not serious. It has been traced to a flange on a single reaction control system thruster. According to NASA, the leak is stable and "would not pose a risk at that level during the flight."

Engineers performed pressure testing on the system, which "indicated the rest of the thruster system is sealed effectively across the entire service module."

Currently, the Atlas V rocket and Starliner are in the Vertical Integration Facility at Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida.

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The launch follows 2019's near-catastrophic first test flight of an uncrewed Starliner, where iffy quality control processes left the Calamity Capsule unable to reach the International Space Station (ISS).

The Starliner team tried again in 2022 and managed to reach the ISS, although not without incident, including thruster problems.

A successful conclusion to the mission cleared the way for a crew to be blasted to the ISS, but delays, including worries about the parachutes, have beset that stage. The helium leak is the latest problem faced by the team.

Boeing's rival in the crew transportation arena is SpaceX, which has managed ten flights to the ISS, of which one was uncrewed and the other a demo flight with only two crew members on board. It has also flown four non-governmental private missions. The company first docked a crewed capsule to the ISS in 2020.

The aerospace giant has now notched up well over $1 billion in losses over the CST-100 Starliner program. ®