Starliner in orbit
Boeing's CST-100 Starliner will reach the ISS a little more than a day after its scheduled Dec. 20 launch from Cape Canaveral, Florida. Credit: Boeing

WASHINGTON — A second uncrewed test flight of Boeing’s CST-100 Starliner commercial crew spacecraft is now scheduled for no earlier than the end of March, 15 months after its first, flawed mission.

NASA and Boeing announced Dec. 9 that the launch of the Orbital Flight Test (OFT) 2 mission is scheduled for March 29 on a United Launch Alliance Atlas 5 rocket from Cape Canaveral. That is three months later than the last formal update for the mission announced by the organizations in August, when they still hoped to fly the mission by the end of 2020.

Agency officials said last month that updates to the spacecraft’s software was driving the revised launch schedule. “The pacing item really is getting the software ready to go,” said Steve Stich, NASA commercial crew program manager, at a press conference in November ahead of SpaceX’s Crew-1 commercial crew launch. At the time he said the launch was expected no earlier than the first quarter of 2021. “As they continue to make progress on the flight software and the testing of that software, we’ll be able to refine that date a little bit better.”

NASA said in a statement about the new OFT-2 launch date that Boeing had completed more than 90% of the recommended actions from an independent review earlier this year of the original OFT mission. “NASA and Boeing are doing a tremendous amount of work on all aspects of their flight software,” Stich said in the statement.

“With each vehicle closeout, line of code tested and document delivered, we’re on a path to proving we have a robust, fully operational vehicle,” said John Vollmer, Starliner vice president and program manager at Boeing, in a statement.

Boeing announced in April it would fly the OFT-2 mission, at its own expense, after the OFT mission in December 2019 suffered problems that truncated its mission and prevented the spacecraft from docking with the International Space Station. Those problems included a miscalibrated timer that led the spacecraft to think it was in the wrong phase of its mission immediately after launch, and another software flaw corrected just before reentry that could have caused the spacecraft’s service module to collide with the crew capsule after separation.

While engineers complete updates to the spacecraft’s software, the spacecraft itself is nearing final assembly, Boeing said, with all the major components if the crew capsule installed and final checkouts of systems underway. It will then be mated to the spacecraft’s service module, which is already complete.

Despite the delay in the OFT-2 mission, NASA and Boeing said they’re still planning to follow it with a Crew Flight Test (CFT) mission in the summer. In August, when OFT-2 was scheduled for launch at the end of 2020, NASA said CFT would fly no earlier than June 2021.

The CFT mission will fly NASA astronauts Mike Fincke, Nicole Mann and Barry Wilmore to the ISS. NASA and Boeing announced in October that Wilmore would replace Boeing’s Chris Ferguson, who stepped aside from the CFT mission for personal reasons.

NASA hasn’t announced how long the CFT mission will last. NASA had prepared to extend what was originally envisioned as a short test flight to a stay of as long as six months on the ISS when it was worried that delays in the commercial crew program would jeopardize access to the station. With SpaceX’s Crew Dragon now in service, those concerns have faded.

NASA had targeted the launch of the second operational Crew Dragon mission, Crew-2, for as soon as late March, but the decision to schedule OFT-2 for that date suggests that Crew-2 could be moved to later in the spring, avoiding conflicts with both OFT-2 and a Soyuz mission planned for April. There are only two docking ports on the ISS for commercial crew vehicles, with the Crew-1 spacecraft occupying one of them.

The schedule for a third Crew Dragon mission, as well as the first operational Starliner mission, Starliner-1, remain uncertain. NASA announced in August that Starliner-1, with NASA astronauts Sunita Williams, Josh Cassada and Jeanette Epps, along with a fourth crew member yet to be assigned, would launch no earlier than the end of 2021.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...