NASA Administrator Jared Isaacman formally classified the 2024 crewed flight of the Starliner spacecraft as a “Type A” mishap in February, acknowledging that the test flight was a serious failure. Two of NASA’s senior human spaceflight officials left their posts later that month.

The inspector general reported that “ambiguity in NASA requirements and delays in the appropriate mishap classification hindered the resolution of CFT issues.”

While agreeing with NASA’s decision to fly only cargo on the next Starliner mission, the inspector general wrote that a flight without astronauts would not satisfy all of the agency’s human-rating certification milestones. It also means NASA will have to buy an additional crew transportation mission to cover the services Starliner-1 would have originally provided. This will cost approximately $300 million.

“This decision increases NASA’s costs to maintain a crewed ISS, along with compounding the ongoing delays with certifying the Starliner and reducing the number of contracted crew flights NASA has under (the Commercial Crew contract),” the inspector general wrote.

There are other costs, too. NASA paid SpaceX $17 million to accelerate Crew Dragon flights to fill the gap left by the Starliner delays. The inspector general also questioned nearly $128 million in payments to Boeing since 2019 for the future Starliner-3 crew rotation flight, “a mission that is far from certain.”

Once NASA and Boeing are ready for Starliner to return to flight, Boeing must find a slot in United Launch Alliance’s schedule to fly the Starliner-1 mission on an Atlas V rocket. NASA must also fit Starliner-1 into a busy schedule of missions coming and going at the ISS.

“Furthermore, Boeing is facing additional scheduling constraints, including launch availability, docking port access on the ISS and crew training timelines,” the inspector general wrote. “As a result, the human-rating certification may be delayed to 2027, leaving a limited window of only being able to provide crewed flights to 2030, the planned end of the ISS’s operational life.”