Just a couple of weeks after SpaceX founder Elon Musk emerged victorious from a battle for moon supremacy with fellow billionaire space explorer Jeff Bezos, the lunar lander contract has taken a new twist.
Blue Origin, founded by the former Amazon CEO, had asked the US Government Accountability Office (GAO) to overturn an April decision to award the multi-billion dollar contract to SpaceX.
That appeal was turned down earlier this month, just days after Bezos had offered NASA a US$2 billion discount to give the contract to Blue Origin instead - and now the billionaire's company is suing.
The latest fight, filed in federal court, continues the argument that NASA's decision to award the sole contract to SpaceX was "fundamentally unfair".
The space agency had previously indicated it may pick two companies to help deliver the lunar lander but changed tack when it learned it didn't have enough funding to do so.
"Blue Origin filed suit in the US Court of Federal Claims in an attempt to remedy the flaws in the acquisition process found in NASA's Human Landing System," a spokesperson for the company told website Engadget.
"We firmly believe that the issues identified in this procurement and its outcomes must be addressed to restore fairness, create competition, and ensure a safe return to the moon for [the United States of] America."
When GAO announced the decision to confirm SpaceX as the contract winner, NASA said that sending astronauts to the moon, a priority for the Biden administration, could now move forward.
"GAO's decision will allow NASA and SpaceX to establish a timeline for the first crewed landing on the moon in more than 50 years," NASA said in a statement.
Work was halted when the original decision was appealed to the GAO and The Verge reports Blue Origin will request an order to halt SpaceX's work on the contract until a decision is made by the court.
This court case is the latest blow to NASA's Artemis programme, the code-name of the plan to land astronauts back on the moon.
Last week the Office of Inspector General (OIG) said hopes the agency had of a lunar landing by 2024 were all but impossible.
The delays in the lunar landing module was one of the reasons specified, but the development of new spacesuits was the major factor.
With more delays anticipated due to the pandemic and technical issues, "a lunar landing in late 2024 is not feasible", the report concluded.