THIS IS DISAPPOINTING: NASA’s next flagship telescope is “not executable” in its current form.

A new report—released without fanfare on the Wednesday before the Thanksgiving holiday—calls into question the viability of the project. “The risks to the primary mission of WFIRST are significant and therefore the mission is not executable without adjustments and/or additional resources,” the report states. It estimated the cost of the project at $3.9 billion to $4.2 billion, significantly above the project’s $3.6 billion budget.

Produced by an independent and external team to review the technical aspects of the program, its management, and costs, the report is critical of a series of key decisions made by NASA. The addition of a coronagraph and other design choices have made for a telescope that is “more complex than probably anticipated” and have substantially increased risks and costs, according to the report.

It also offered a scathing review of the relationship between NASA headquarters and the telescope’s program managers at Goddard Space Flight Center. “The NASA HQ-to-Program governance structure is dysfunctional and should be corrected for clarity in roles, accountability, and authority,” the report states.

Just the surreptitious timing of the report lends it more credibility than NASA has enjoyed in recent years, but I do hope they get the bugs worked out of WFIRST quickly enough to make it a success.