Boeing's Starliner Updates site yesterday posted an update that
Starliner is being returned to the factory for troubleshooting
and the second test flight is off until further notice. The notice in
its entirety reads:
Today, Boeing informed NASA that the company will destack its CST-100 Starliner from the Atlas V rocket and return the spacecraft to the Commercial Crew and Cargo Processing Facility (C3PF) for deeper-level troubleshooting of four propulsion system valves that remain closed after last Tuesday’s scrubbed launch.
Starliner has sat atop the Atlas V rocket in ULA’s Vertical Integration Facility since August 4, where Boeing teams have worked to restore functionality to the affected valves.
The relocation of the spacecraft to the C3PF will require Boeing, NASA and United Launch Alliance to agree on a new launch date once the valve issue is resolved.
“Mission success in human spaceflight depends on thousands of factors coming together at the right time,” said John Vollmer, vice president and program manager, Boeing’s Commercial Crew Program. “We’ll continue to work the issue from the Starliner factory and have decided to stand down for this launch window to make way for other national priority missions.”
Starliner while still on the Atlas V launch vehicle in the Vertical
Integration Facility. Boeing photo.
The delay seems to be entirely the right thing to do. The message they Tweeted was much shorter (I assume due to Twitter limits) but said they're "standing down to make way for other national priority missions."Those familiar with the schedules for the rest of the year are saying that the most likely time frame to try to schedule for is February of 2022, and even that is daunting. That depends on Boeing finding the root cause of the valve issue, identifying a fix, implementing it, and successfully testing it.
According to Vollmer, some of the NTO leaked through seals on the valves. Such leaks are well understood from a physics standpoint, Vollmer said. But then this oxidizer combined with some unanticipated ambient moisture in the cavity around the valve, and this resulted in corrosion that prevented the valves from opening properly.
It is not clear how this moisture got into the spacecraft. While there were thunderstorms when the vehicle was on the Florida launch pad in early August, the ambient moisture did not come from those storms. It could have been due to the humid Florida atmosphere, however. This is one of the issues that Boeing must now investigate alongside engineers from NASA and Aerojet Rocketdyne, which manufactured the spacecraft thrusters.
If this is from needing better protection from humidity or more waterproofing,
that means it's a hardware problem and not software which is probably better for everyone. The running joke in
the hi-rel avionics world when I left it was that the attitude used to be "fix
it in the software" until that resulted in so many fusterclucks that it became
cheaper and easier to "fix it in the hardware". There are whole industries dedicating to torturing hardware to verify it will survive the worst possible "real world" conditions.