Boeing
Boeing and NASA have said the Starliner spacecraft is ready for unmanned flight, and a second uncrewed test mission for the spacecraft is now scheduled for May 19.
It’s been nine months since a standard pre-flight check of the spacecraft, then atop a rocket on the launch pad in Florida, found 13 of 24 oxidation valves in the Starliner’s propulsion system stuck. The discovery was made within hours of takeoff.
Since then, engineers and technicians at Boeing and NASA have worked to understand exactly why the valves stopped and to fix the problem. They found that a dinitrogen tetroxide oxidizer loaded onto the spacecraft 46 days before launch combined with ambient moisture to form nitric acid, which started the corrosion process on the valve’s aluminum housing.
Boeing and NASA officials on a conference call with reporters Tuesday discussed the steps they have taken to mitigate the problem of the upcoming Starliner test flight. Michael Parker, vice president and deputy general manager of Boeing Space and Launch, said the valves in the car remained the same, but engineers closed the pathways that allow moisture to enter the propulsion system. It also extracts moisture from the valves using nitrogen gas and propellant on the Starliner as launch approaches.
With these measures in place, the Starliner will soon be stacked atop an Atlas V rocket built by United Launch Alliance. The Starliner was scheduled to roll out on Wednesday at the Atlas V launch complex in Florida, but Boeing said: Operation halted due to hydraulic leakage in the United Launch Alliance powertrain.
So this is in line with Boeing’s on-and-off efforts to bring the Starliner into service. The company has been working on the vehicle since 2010, when it was called Crew Space Transportation-100, or CST-100. The Starliner made its first flight in December 2019, but problems arose minutes after takeoff when the spacecraft picked up the wrong “mission interval” from the Atlas V launch vehicle. It also had difficulty communicating with ground stations. NASA and Boeing flight controllers were able to restore communications with the Starliner and help it reach orbit. However, due to the fuel consumed during these operations, the Starliner was unable to achieve its primary goal of safely docking with the International Space Station.
There were also problems during the flight back to Earth. Another software bug was discovered and fixed a few hours before the car re-entered Earth through the atmosphere, and it could have caused the thrusters to fire incorrectly in the Starliner service unit. The car was about to get lost a second time.
These problems led NASA to announce the first test flight of the Starliner. A “close call in HD” and the start of years of research and deep diving into the problems of the Starliner program. Boeing agreed to pay for a second test flight at a cost of $410 million, eventually setting up the Orbital Flight Test-2 mission, which reached the platform in the summer of 2021. Then the car had a valve problem. Poster Finally, the company has the Starliner back on stage, ready to close again.
NASA, of course, currently owns SpaceX’s Crew Dragon spacecraft to carry its astronauts to and from the International Space Station. The Crew Dragon has done five largely manned missions since mid-2020, but with tensions rising between the United States and Russia, NASA would like it to have the option of moving a second crew member to go to the station.
This means that NASA is very interested in the second Starliner test. The success of this test flight will likely lead to Boeing flying the crew to the space station for the first time as early as 2023.
“This is a very important step in our ongoing goal of having American transport capabilities to the International Space Station,” said NASA’s Cathy Ludders, chief of manned space operations. “Strong crew services are very important to our continued commitment to the scientific and technological research and development we make on the International Space Station, and it is critical that we achieve our exploration goals.”
