While the investigations continue, Boeing meanwhile has offered to reimburse the government the full cost of the tanks regardless of any responsibility determinations.

"Boeing has offered to compensate NASA for the hardware, and continue to focus on program objectives," said Joe Mills, Boeing ISS deputy program manager.

"As prime contractor we have a good track record of properly caring for and handling government property, and we are doing everything we can to resolve this issue."

An investigation continues to fully understand how two oxygen/nitrogen high-pressure gas tank orbital replaceable units were misplaced in February during manufacturing assembly operations at Marshall.

The most probable explanation of the misplacement of the tanks is that the flight hardware items were inadvertently discarded, along with the associated shipping containers, into a trash dumpster and were subsequently discarded.

"A Mishap Report, which documents the findings and recommendations of a joint Boeing/NASA independent Incident Review Board, will be formally released early next week," said Mills. "Boeing already is taking corrective actions to fully implement the recommendations of this Board."