Nasa is suing former astronaut Edgar Mitchell to get back a camera that went to the moon on the Apollo 14 mission.
The lawsuit filed in South Florida federal court contends Mr Mitchell recently tried to sell the camera at an auction.
Nasa says there is no record that the device was ever transferred to Mr Mitchell and Nasa wants it back.
Mr Mitchell became the sixth person to walk on the moon during the 1971 Apollo 14 mission. He now lives in Lake Worth.
The 16mm camera is known as a Data Acquisition Camera. It was one of two that went to the moon on Apollo 14.