A survey of astronauts and flight surgeons found no evidence of launch-day drinking by crew members, despite a report last year of two cases of drunkenness.

Ellen Ochoa, left, of NASA's Johnson Space Center in Houston, answers questions during a news conference on July 27, 2007.
(Charles Dharapak/Associated Press)

The anonymous survey uncovered a single case of "perceived impairment" by someone just a day or more from blasting into space, and it turned out to be a reaction between prescription medicine and alcohol.

NASA officials, citing medical privacy, refused Wednesday to say when or where the episode occurred, only that it happened on one of the final days leading up to launch, but not on launch day.

The crew member was cleared for flight and rocketed into space.

The officials said they didn't know whether the specified case was one of the two alleged cases of astronaut drunkenness cited in a report by medical experts last summer.

NASA has yet to receive any proof or information about astronauts drinking heavily in the 12 hours before liftoff, said Ellen Ochoa, deputy director of the Johnson Space Center in Houston.

No policy changes planned

"We really never understood from the beginning exactly what might have led to the comment in the health-care report," Ochoa, a former shuttle astronaut, said at a news conference.

"We've tried to run it to ground."

None of those surveyed last fall, 87 of 98 astronauts and all 31 flight surgeons, reported seeing a crew member drinking alcohol on launch day.

No policy changes are planned for either drinking or handling medication and the 12-hour pre-flight ban on drinking remains in effect.

A new astronaut code of conduct, though, is almost complete.

The allegations of drunken astronauts arose last July, just months after the arrest of one-time shuttle flier Lisa Nowak.

Nowak incident led to review

She chased her astronaut-boyfriend's new girlfriend from Houston to Florida last February and ended up in jail for it.

She has yet to stand trial.

Because of the Nowak scandal, NASA established a panel of aerospace medicine experts to look into astronaut mental health.

The experts, citing unidentified sources, reported heavy drinking by two astronauts just before their respective launches, one from Cape Canaveral and one from Kazakhstan.

Doctors' concerns about the astronauts' drunken state were supposedly overruled by management.

The panel's report stated that flight surgeons' medical opinions were not valued by NASA managers, and that astronauts and flight surgeons were reluctant to report improper conduct.