U.S. President Barack Obama signed a bill into law Sept. 25 granting NASA’s Mercury, Gemini and Apollo crew members “full ownership rights” to the artifacts they received and retained more than 40 years ago.

The legislation, H.R. 4158, was authored in response to recent challenges raised by NASA’s General Counsel and Office of Inspector General about the attempted sale by several astronauts of their mementos. The issue came to a head in January after an inquiry by the space agency put a hold on the almost $400,000 auction of a checklist used by Apollo 13 commander James Lovell.

The bill clarifies what NASA Administrator Charles Bolden described as “fundamental misunderstandings and unclear policies.”

“NASA is pleased ownership of flight mementos and other artifacts of the Mercury, Gemini and Apollo astronauts is no longer in question,” NASA spokesman Robert Jacobs said in a statement issued Sept. 26. “We appreciate the expeditious consideration by Congress to clarify ownership of these mementos and the patience of the astronauts, museums, learning institutions, and others who have these artifacts [from] the astronauts in personal and private collections.”

“This bill seeks to eliminate any further ambiguity about Apollo-era artifacts that were received by the astronauts. It simply says that astronauts who flew through the end of the Apollo program will be granted full right of ownership of any artifacts received from their missions,” House Science, Space and Technology Committee Chairman Ralph Hall (R-Texas) said in a statement.

Hall and Rep. Eddie Bernice Johnson (D-Texas), the committee’s ranking member, introduced the bill in March. It was passed by the House Sept. 19. The Senate approved the bill Sept. 22, prior to leaving on recess.

The question behind the legislation — whether astronauts hold the rights to expendable space equipment, including their checklists, personal hygiene kits and items that, had they been left aboard the Apollo lunar module, would have been crashed into the Moon — had gone largely uncontested by NASA until last year.

Then, in a series of challenges, including a lawsuit brought against Edgar Mitchell, who was the sixth man to walk on the Moon, NASA counsel began to insist that if paperwork could not be produced documenting that the equipment had been released to the astronaut, then it was not legally his to own, donate or sell.

In Mitchell’s case, the government sought the return of the data acquisition camera that he saved from being destroyed on the Moon. Ultimately, Mitchell settled out of court, agreeing to turn the camera over to the Smithsonian for its display.