HOW astronauts go to the toilet in zero gravity has always interested some. Now it can revealed unwanted difficulties - among them issues of ownership - can arise.

Newly-released transcripts from NASA's Apollo 10 mission to the moon in May 1969 show that when it came to boldly going, all was not well.

Astronauts Thomas Stafford, John Young and Eugene Cernan had, judging by the transcripts, profound difficulty managing the spacecraft's toilet, the Daily Mail reported.

Apollo 10's Commander, Thomas Stafford, was first to realise there was a problem.

"Give me a napkin quick ... there’s a turd floating through the air," he said.

John Young, the Command Module Pilot, quickly replied: "I didn’t do it. It ain’t one of mine."

Eugene Cernan, the Lunar Module Pilot, quickly realising the blame was shifting towards him, shot back: "I don’t think it’s one of mine."

Stafford then retorted: "Mine was a little more sticky than that. Throw that away."

Young retorted: "God almighty" before laughter is heard.

Cernan then discovers there's more than one piece of human waste floating in the cockpit.

"Here’s another goddamn turd. What’s the matter with you guys? Here, give me a –" which is greeted with laughter from Stafford and Young.

Stafford asks: "It was just floating around?"

Cernan: "Yes."

The issue was reviewed after the mission ended, with NASA experts concluding that correctly using the "facilities"in space - ie, a strategically-positioned plastic bag - required "a great deal of skill".

"In general, the Apollo waste management system worked satisfactorily from an engineering standpoint," according to the biomedical review said. "From the point of view of crew acceptance, however, the system must be given poor marks."

Apollo 10 was the fourth manned mission in the US Apollo space program. Its purpose was to be a "dry run" for the Apollo 11 mission, testing the procedures and components of a Moon landing without actually landing on the Moon itself.