الاثنين، 16 مايو 2022

Boeing May Be Headed For Another Round of Starliner Design Changes

All is not well with Boeing’s Starliner spacecraft, which was supposed to be certified and ready to ferry astronauts to and from the International Space Station (ISS) by now. The company is barreling toward a crucial May 19th test flight, but a new report says Boeing is still bickering with supplier Aerojet Rocketdyne about who is to blame for the vessel’s defective fuel valves. The end result may be a complete redesign of the system before the spacecraft is ready for crewed flights. 

To recap, the CST-100 Starliner is Boeing’s contribution to the NASA Commercial Crew Program. Along with SpaceX, Boeing was tasked with building a spacecraft to replace the Space Shuttle and free the US of reliance on Russian Soyuz capsules to access the ISS. SpaceX pulled ahead and is now regularly flying crew to the station. Boeing, however, has encountered one problem after another as it tries to get Starliner up and running. 

The current sticking point is the spacecraft’s fuel valves. Of the 24 oxidizer valves in the system, 13 of them were stuck and not responding to commands when Boeing tried to launch Starliner in August of last year. It scrubbed the launch and disassembled the hardware to track down the issues, which turned out to be related to humidity. Water accumulated in the system and reacted with the dinitrogen tetroxide oxidizer to produce nitric acid, which corroded the aluminum valves. 

Earlier this month, Boeing said it had addressed the issue by adding additional seals to prevent water infiltration, and it wasn’t planning to redesign the hardware. According to Reuters, Boeing is going back and forth with supplier Aerojet Rocketdyne, with both companies blaming the other for the issues. This comes as Boeing has spent an additional $595 million due to delays in the fixed-value $4.2 billion contract. With each delay, the costs mount. That might explain why Boeing is so anxious to fly Starliner without redesigned valves, but it’s not a good look when pieces just fall off on the way to the launchpad. 

The upcoming flight is known as Orbital Flight Test 2 (OFT-2), which is a re-run of the OFT test from 2019 when Starliner malfunctioned and failed to reach the ISS. Boeing needs to complete this flight and then follow up with a crewed test flight before it can begin regular Commercial Crew operations. Whether Starliner will have the same problematic valves at that point is now less certain. In a recent press conference, Boeing VP Mark Nappi admitted that a valve redesign is “on the table.” Boeing also tells Reuters that it is looking at “short- and long-term design changes to the valves.” The specifics will probably depend on the outcome of its discussions/arguments with Aerojet Rocketdyne.

SpaceX, meanwhile, has been handling all of NASA’s crewed ISS flights with the Dragon and Falcon 9 combo. That gives NASA some wiggle room, but the agency clearly expected to have two operational vehicles in 2022—the agency awarded SpaceX more launch contracts to make up for Boeing’s delays, and it moved some crew from Boeing missions to SpaceX. Boeing is confident that OFT-2 will go off without a hitch, but it’s anyone’s guess how extensive the valve redesigns will be. One thing is certain, though. Boeing is running out of chances to get this right.

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