"That's not the 'right stuff' as far as I'm concerned," said Congressman Bart Gordon, chairman of the House Science and Technology committee.

A special panel charged with studying astronaut health found 'heavy use of alcohol' before launch, which may have lead to life-threatening situations on at least two occasions.

NASA are officially vague on the risks, stating that the allegations are based on anonymous interviews and are unsubstantiated.

When space operations chief Bill Gerstenmaier was asked if he knew of any such incidents, he said: "The obvious answer is no. I've never had any instances of that."

"There's not been a disciplinary action or anything I've been involved with regarding this type of activity."

NASA is releasing two reports into astronaut's health, one by an external committee and another by an internal panel.

The agency is currently dealing with the fallout from the Lisa Nowak case, where one of their astronauts involved in a love triangle plotted to kidnap her rival.

Any scrutiny of astronaut's behaviour is likely to cause more trouble for an already embattled administration.

"If the reports of drunken astronauts being allowed to fly prove to be true, I think the agency will have a lot of explaining to do," Congressman Gordon said.