The independent panel also found "heavy use of alcohol" before launch, the magazine reported, although that drinking did not contravene the standard 12-hour "bottle-to-throttle" rule.

 

A Nasa official confirmed the report contained such details, but said they were from anonymous interviews and not substantiated. Nasa is to discuss the health report on Friday.

 

The Aviation Week story did not say how long ago the alleged incidents took place, nor did it say whether it involved pilots or other crew members.

 

At a news conference to discuss the forthcoming launch of space shuttle Endeavour set for August 7, Nasa's space operations chief was asked repeatedly about the drunken astronaut report.

 

Bill Gerstenmaier would only say that he had never seen an intoxicated astronaut before flight or been involved in any disciplinary action related to that.

 

Sabotage

 

But he had other bad news, revealing that an employee for a Nasa subcontractor had cut the wires in a computer that was about to be loaded on to the shuttle Endeavour.

 

The subcontractor, which he would not name, contacted Nasa as soon as it learnt that another computer had been damaged deliberately, Gerstenmaier said.

 

Had the contractor not discovered the problem, Nasa would have uncovered it by testing the computer before launch, he said, adding that safety was not an issue.

 

Nasa hopes to fix the computer in time for the launch and also that it will be the last surprise or problem to crop up.

 

The independent panel reviewing astronaut health and Nasa's psychological screening process was created following the arrest in February of former space shuttle flier Lisa Nowak.

 

Nowak is accused of attacking the girlfriend of a fellow astronaut – her romantic rival - with pepper spray in a parking lot at Orlando airport.

 

She was fired in March but has pleaded not guilty to charges of attempted kidnapping, battery and burglary with assault.

 

The scandal was followed by a freak hailstorm that tore into a space shuttle on the launchpad that set back the year's flight schedule.

 

There was also a shooting at Johnson Space Centre in Houston by an employee who eventually killed himself.