NASA revealed that the Boeing Starliner had a potentially "catastrophic" software issue during the capsule's uncrewed test flight in December but said it's too soon to say if another uncrewed test is needed. Boeing stock fell.
On Thursday, NASA's Aerospace Safety Advisory Panel said it recommended reviewing Boeing's software verification processes after discovering another software problem, which wasn't made public earlier.
The Boeing Starliner failed to reach the correct orbit during the test flight in December as the internal timer on the capsule was off by 11 hours, causing the spacecraft to believe that it was further into the mission. NASA and Boeing were candid about the issue during the failed attempt to reach the International Space Station.
The new software issue was discovered during the Starliner's flight, according to panel member Paul Hill. A software fix was made just hours before the capsule returned.
"While this anomaly was corrected in flight, if it had gone uncorrected, it would have led to erroneous thruster firings and uncontrolled motion during [service module] separation for deorbit, with the potential for a catastrophic spacecraft failure," he said, according to Space News.
In a blog post Friday, NASA said its investigation with Boeing has found 11 "top-priority corrective actions" so far with more to be identified.
"There were numerous instances where the Boeing software quality processes either should have or could have uncovered the defects," NASA said.
'A Lot Of Anomalies' On Boeing Starliner
NASA officials are still determining if another uncrewed test flight of the Boeing Starliner is needed before putting astronauts on board. But Boeing has already booked a $410 million Q4 charge in case NASA orders another uncrewed test flight.
At a press conference NASA Administrator Jim Bridenstine acknowledged that the Boeing Starliner test flight "had a lot of anomalies." But when asked whether there will be another Starliner uncrewed flight, he said it's too early to tell that with an independent investigation still ongoing.
The possible "catastrophic" glitch could have resulted in the Starliner module and thruster bumping into each other during separation, officials said. In theory, it could have damaged the heat shield, depending on where it bumped into each other. The crew module could also have become unstable and started to tumble in space.
"Nothing good can come from those two spacecraft bumping," said Jim Chilton, Boeing's senior vice president for space and launch.
He added that after the timer error occurred, Boeing and NASA looked for other potential software problems and found the new one. which wouldn't have been found otherwise.
Now, Boeing and NASA have to go through all of the Starliner's software, which includes about 1 million lines of code, said John Mulholland, program manager of the Boeing Starliner program.
Boeing Starliner vs. SpaceX Crew Dragon
Elon Musk's SpaceX and Boeing have separate contracts with NASA to develop their own spacecraft for ferrying astronauts to and from the International Space Station. When NASA awarded the contracts in 2014, it envisioned SpaceX and Boeing would begin their so-called space taxi service by 2017. But delays have plagued both programs.
Bridenstine has been critical of Musk's focus on its deep-space Starship and Super Heavy booster when SpaceX was behind schedule on the Crew Dragon. But Musk has said the vast majority of SpaceX resources are committed to the Crew Dragon.
SpaceX aced its in-flight abort test last month, which was needed before a crewed test to the ISS could be launched. SpaceX's first crewed test flight is expected this spring.
Meanwhile, Boeing is struggling to fix software issues with its 737 Max commercial jet following two deadly crashes.
Follow Gillian Rich on Twitter @IBD_GRich for space news and more.