Boeing's Starliner undocks from the International Space Station at the conclusion of the Crew Flight Test mission. Credit: NASA

WASHINGTON — A NASA official says that work with Boeing on the company’s CST-100 Starliner vehicle is making “good progress” but declined to offer a date when the spacecraft could fly again.

During a July 30 briefing on upcoming spacewalks at the International Space Station, Bill Spetch, deputy manager of NASA’s Commercial Low Earth Orbit Program, said NASA was working “very closely” with Boeing to address propulsion system issues with Starliner on a crewed test flight two years ago. Starliner has not flown since that mission.

Kelly Ortberg, Boeing’s president and chief executive, said on a July 28 earnings call that work on Starliner was going well and suggested the main issue was scheduling the Starliner-1 mission, a cargo-only flight that will effectively serve as another test flight for the spacecraft.

“We’ve got to work with NASA to align on when the launches are going to be, both the crewed and uncrewed launches, going forward,” he said in the call. Boeing separately stated in a Securities and Exchange Commission filing that the company was planning Starliner-1 for no earlier than the fourth quarter of this year.