In response, NASA said it launched an investigation to try to verify the allegations, embraced an astronaut code of conduct and was weighing changes in its drinking policies.
NASA convened the eight-member panel to examine its health policies after the arrest of astronaut Lisa Nowak in February on allegations she stalked and attacked a rival for the affections of a fellow astronaut.
"Interviews with both flight surgeons and astronauts identified some episodes of heavy use of alcohol by astronauts in the immediate pre-flight period, which has led to flight-safety concerns," the report said.
The panel did not say when the incidents took place or name the astronauts involved.
"We don't have enough data to call it alcohol abuse," said U.S. Air Force Col. Richard Bachmann, panel chairman and commander of the Air Force School of Aerospace Medicine, who offered few details of the two incidents cited in the report.
