NASA and Boeing have once again postponed the first crewed flight of the company’s CST-100 Starliner while they work to fix a helium leak in the spacecraft’s propulsion system. NASA announced on May 17 that the Crew Flight Test (CFT) mission, previously scheduled for May 21, has been rescheduled to 15:09 on May 25 to continue working on the helium leak. Supercharger system on a spacecraft.

The latest disruption comes three days after NASA and Boeing said they were delaying the May 17 launch to fix a helium leak in the engine in the spacecraft’s service module. The leak was found in the flange of a thruster, and Boeing said at the time that it was working to better characterize the leak and develop a flight scenario to use the system as is, without replacing the flange.

While announcing the new delay, NASA said, “Pressure testing of the spacecraft’s helium system conducted on May 15 showed that the leak in the flange was stable and would not pose a risk at this level during flight.” said. “Boeing teams are working to develop operational procedures to ensure the system maintains adequate performance and adequate redundancy in flight.”

NASA added that its commercial crew and International Space Station programs should “review data and procedures to make a final decision before moving forward with the flight countdown” over the next few days.

The announcement came after hours of speculation about a new delay for the mission, which as a whole has suffered many disruptions due to various technical problems with the spacecraft, from valves to parachutes. Boeing provided few additional details about the helium leak and did not respond to previous questions about it.

According to industry sources, the leak was discovered during the countdown on May 6 and was addressed due to an unrelated valve issue in the Atlas 5 Centaur upper stage. It is unclear whether the launch could have continued had the valve been working properly.

Boeing vice president Mark Nappi, who heads the company’s Starliner program, did not mention the helium leak or other problems with the spacecraft during the May 6 post-cleanup briefing. “Today was a good dry launch for the whole process,” he said at the time, and launch preparations went smoothly until the launch was completed about two hours before the scheduled launch. “We were about 45 minutes ahead of schedule, so the teams did a great job.”

“A lot of things need to be right. Most things are not; Everything needs to be right before launch,” he added.