NASA has also designated December’s failed test flight of the Boeing Starliner as a serious “high-visibility close call” that could have destroyed the capsule not once, but twice, according to the Associated Press.
This formal designation kicks off additional government review on the CST-100, and NASA is expected to follow the corrective measures taken very carefully.
During the December test flight, the first software issue came up shortly after Starliner launched when the capsule failed to execute an orbit-insertion burn.
That issue was caused when the Starliner’s onboard “mission elapsed timer” erroneously pulled an incorrect time from the Atlas V rocket nearly 11 hours before liftoff.
The information was supposed to be retrieved during the actual countdown, before liftoff, but because it was the wrong data, Starliner’s internal clock did not have the correct time.
The next really big issue occurred when a second software problem was discovered before the spacecraft’s return to Earth, and it could have led to a collision between the Starliner’s crew module and its service module. Boeing officials described it as a “valve mapping error,” that had to do with the software that tells Starliner’s crew module and service module to separate before landing.
That particular software problem was detected before the descent of the module. “The team very quickly recoded the software, reverified it in the labs, and were able to upload that software correction and safely complete the mission.
Corrective actions needed
All told, Boeing said Friday that NASA found about 61 “corrective actions” for the company’s Starliner spacecraft that need to be addressed before the spacecraft can fly NASA astronauts.
NASA associate administrator Doug Loverro told reporters on a conference call that he expects it “will take several months” for Boeing to work through the list, according to CNBC News.
“This was a close call. We could have lost a spacecraft twice during this mission,” Loverro said.
The approximately 61 recommendations are not to be thought of as 61 individual issues related to the spacecraft, said Boeing. But there are three primary technical and design issues that the company is addressing. However, Loverro noted that it does not mean there are only three problems with Starliner. He said there are more issues, although he wasn’t sure of a specific number identified by investigators.
Boeing’s software problems made it into the spacecraft due in part to Boeing’s failure to carry out “end-to-end” tests of the systems in question before launch. Instead, Boeing engineers relied on emulators that act as electronic stand-ins that don’t always reflect the actual behavior of flight software.
Additionally, some critical software was tested in segments that masked problems that otherwise might have been caught and corrected.
A key unknown
The question on many people’s minds is whether NASA will require a second unpiloted orbital flight test or OFT to verify if all systems on the CST-100 are working correctly. According to Space Flight Now, Boeing could develop a rationale for pressing straight ahead to a crewed flight test, or CFT, to the International Space Station.
“Quite frankly, right now we don’t know,” Loverro said. “They have to now come back to NASA with a plan, how they’re going to go ahead and address all of those (recommendations). … We will do our own inspection of the results of their work. And then we’ll be in a position to decide whether or not we need another (uncrewed) test flight or not.
“So we are still a ways away from that. And I can’t even tell you what the schedule is for making that decision because it’s very dependent upon what we see as Boeing’s corrective action plan and the thoroughness by which we believe that correction action plan has been implemented.”
