Boeing recently completed its formal requalification of the CST-100 Starliner’s flight software in preparation for its next flight. The autonomous spacecraft will fly to the International Space Station during a second uncrewed flight test, Orbital Flight Test-2, in March, ahead of a first crewed flight with NASA astronauts later this year.
Teams in Houston and across the country conducted a full review of Starliner’s flight software and the process by which mission modifications or upgrades will be formally qualified in the future.
“The work this team put into exhaustively wringing out our software is a defining moment for the program,” said John Vollmer, Starliner vice president and program manager. “We’re smarter as a team having been through this process, and most importantly, we’re smarter as a human spaceflight community.”
The team began by evaluating Starliner’s software requirements and the testing associated with its verification. Reviews were conducted to ensure Starliner’s Houston-based Avionics and Software Integration Lab, or ASIL, was sufficiently outfitted and configured to support all testing. Additional assessments were made to verify the complete integration of software with all recommended flight hardware. Software engineers also validated all the simulators and emulators to ensure they were accurate models.
The team then conducted a series of tests to confirm Starliner’s updated software met design specifications. They also conducted static and dynamic tests inside the software integration lab, including hundreds of cases ranging from single command verifications to comprehensive end-to-end mission scenarios with the core software.
When the COVID-19 pandemic threatened the team’s progress, the program swiftly transitioned to virtual work, and enlisted support from across the company.
“Throughout all the turmoil 2020 handed us, this team remained energetic and inspired to be successful,” said Aaron Kraftcheck, Starliner’s software test and verification manager. “They want to do their very best for their country and their fellow citizens by helping to restore the pride NASA has in flying humans safely in space.”
Hardware and software integrated test events are planned with the spacecraft’s launch vehicle provider, United Launch Alliance, to further strengthen that portion of the qualification test regimen, and with NASA’s International Space Station program to verify Starliner’s code is robust and error-free throughout joint docking and undocking operations.
Boeing will then run through an end-to-end simulation of the OFT-2 test flight in the company’s ASIL using flight hardware and the final versions of Starliner’s flight software to accurately model the spacecraft’s expected behavior. The simulation will be conducted over several days and includes complete pre-launch to docking and undocking to landing events.
“As we continue carrying out these critical milestones and reviews, we remain true to our values of safety, quality and integrity,” Vollmer said. “Completing OFT-2 brings us one step closer to our end goal of transporting astronauts to and from the International Space Station this year.”