Boeing Starliner achieves Requalification of Software

Boeing has finished the software requalification of all its commercial spacecraft crew as it expects to deploy the aircraft for a second flight test by late March. Boeing reported that on January 18, on CST-100 Starliner spaceship, it had completed a “formal requalification” of the program. This work involved analyses of the program itself and the methods under which the software was developed and evaluated by Boeing. “A pivotal point for the system is the effort this team has put into comprehensively wringing out the software,” John Vollmer, Starliner’s vice president as well as program manager, stated in a corporate statement, “As a team that has been through this phase, we’re stronger, and most significantly, as a human spaceflight culture, we’re smarter.”

At the center of the December 2019 spacecraft’s defective initial test mission, software bugs were recognized as the Orbital Flight Test (OFT). The Starliner’s timer was off by eleven hours, leading the spacecraft to believe that it was in a new mode of flight shortly after spacecraft divergence. The spacecraft ended up requiring more fuel than expected for its thrusters to enter orbit, leaving out a scheduled docking with International Space Station. Engineers later noticed a second software issue that may have prompted the spacecraft’s service unit to run into the crew capsule shortly before reentry after the separation.

That risked destroying the capsule’s heat shield or forcing the orientation of the capsule to become unreliable. A few hours before reentry on another shortened test flight, a technical patch to fix the issue was added. Two months after the OFT mission, Boeing executives stated they were revising their software production systems to fix those challenges.  John Mulholland, who works at Boeing as a Starliner program manager at the moment, stated, “We will apply extra rigor to systems engineering as well as software development.” Eighty guidelines were developed by an unbiased analysis of the OFT mission, with software specifications, production, and testing accounting for a significant fraction of them.

In December, the NASA agency said that Boeing had finished work on over 90 percent of the recommendations. With checking the Starliner program, Boeing is not done. Additional analysis is expected to evaluate Starliner’s integration, including Atlas 5 launch vehicle together with the United Launch Alliance (ULA), and to evaluate joint ISS operations with the NASA agency. End-to-end modeling of the forthcoming second OFT mission also will be conducted by Boeing, featuring complete software monitoring from the pre-launch activities through docking, as well as from undocking to touchdown. Last year, Boeing admitted that they did not conduct end-to-end software evaluation but split the experiments into smaller parts instead.