by Boeing’s Starliner astronaut taxi remains on track to launch on Thursday (May 19) on a pivotal test flight to the International Space Station.
Teams with NASA, Boeing and United Launch Alliance (ULA) conducted a launch readiness assessment today (May 17) for Orbital Flight Test-2 (OFT-2), which is an unmanned aerial vehicle starliner on a shake-out cruise to the job lab. All went well, keeping Starliner on course to take off atop a ULA Atlas V rocket on Thursday at 6:54 PM EDT (2254 GMT) from the Cape Canaveral Space Force Station in Florida.
“It was short; it was very clean. There’s really no problem with ULA, Boeing or NASA working on the launch that’s coming,” Steve Stich, manager of NASA’s Commercial Crew Program, said at a news conference today, referring to the review. . “We are now at the point where it is time to start flying with Starliner.”
On photos: Boeing’s Starliner OFT-2 mission in pictures
It took longer to get to this point than NASA, Boeing or ULA thought. OFT-2 was originally scheduled to launch last summer, but engineers discovered during a routine pre-flight check that 13 of the 24 oxidation valves in Starliner’s propulsion system were stuck.
It took about eight months to diagnose and fully address the valve problem, which was caused by a reaction between nitrogen tetroxide oxidizer and moisture in the air. This reaction produced nitric acid, which then reacted with the aluminum housings of the valves to create corrosion products that interfered with the valve’s operation, Boeing representatives said.
Boeing has solved the problem for OFT-2 by cutting off the valves from the humid Florida air, purging the system with nitrogen gas, and turning the valves repeatedly to ensure they are operating normally. But the company can make more substantial adjustments in the longer term.
“There will be some changes; we just need to narrow down what those changes will be,” said Mark Nappi, vice president and program manager of the Boeing Commercial Crew Program, at today’s press conference. “The valve redesign is definitely on the table and the teams are working on some of those options.”
If OFT-2 goes according to plan, Starliner will launch on Thursday and arrive at the space station just over 24 hours later. The capsule will be docked in the orbiting lab for four to five days, then return to Earth for a parachute landing in the western U.S.
Its main purpose is to show that Starliner is ready to transport astronauts to and from the station for NASA, which signed a contract with Boeing for such taxi services in 2014. SpaceX has a similar deal with the space agency and has already launched four operational manned missions to the orbiting lab with its Falcon 9 rocket and Dragon capsule.
As the name suggests, OFT-2 will be Starliner’s second crack at a space station meeting. During the first attempt, in December 2019, the spacecraft received a number of software failures and got stuck in the wrong lane for a rendezvous with the job lab.
Mike Wall is the author of “Outside(Grand Central Publishing, 2018; illustrated by Karl Tate), a book on the search for extraterrestrial life. Follow him on Twitter @michaeldwall† follow us on twitter @Spacedotcom or on facebook†
