An internal NASA health and safety report recommends the space agency explore the idea of drug and alcohol testing for astronauts and other employees.

While the review released Wednesday found no evidence that astronauts were drunk or had been drinking heavily before any space launch — as suggested by an independent panel last month — it cited booze-buying runs made for space shuttle crews awaiting launch.

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The 45-page report by NASA safety chief Bryan O'Connor, a former astronaut and shuttle accident investigator, was initiated after the July report on astronaut health by eight medical experts. That report cited two unsubstantiated incidents of heavy alcohol use just before flights.

"I was unable to verify any case in which an astronaut spaceflight crewmember was impaired on launch day" or any case where a manager disregarded warnings from another NASA employee that an astronaut not fly, said O'Connor's report.

However, O'Connor said NASA doctors should play a stronger "oversight" role on launch day, accompanying astronauts as they suit up for launch. He also recommended that NASA explore the option of drug and alcohol testing for employees, including astronauts.

O'Connor's review looked back 20 years and involved interviews with 90 NASA officials, astronauts and flight surgeons. Twenty flight surgeons signed an e-mail to O'Connor saying they have never seen any drunken astronauts before a launch or training jet flight.

The safety chief toured crew quarters at space centers in both Houston and Cape Canaveral, Fla., as the astronauts were in quarantine days before launch of the shuttle Endeavour earlier this month.

"I saw one half-empty bottle of tequila in one of the cupboards," O'Connor wrote. He also said beer and wine are available from non-flying astronauts making booze runs.

Still, beer and wine consumption now seems less than what was reported in the 1980s and early 1990s, O'Connor reported. It's usually moderate amounts of wine or beer at dinner, during off-duty times, and a far higher percentage of current astronauts are teetotalers these days, he wrote.

He also noted that "the lack of privacy on launch day makes it nearly impossible to hide alcohol use or alcohol-induced impairment."

Even so, O'Connor's report recommended that excessive drinking be added to NASA's list of risky activities forbidden for astronauts about to fly, along with motorcycle racing, parachuting and firefighting.

O'Connor looked through 40,134 government and contractor reports of mishaps and problems dating back through 1984 — many of them anonymous — and none of them involved alcohol or drug abuse by astronauts.

The careful look at astronaut health issues grew out of the scandal earlier this year involving astronaut Lisa Nowak, accused of the assault and attempted kidnapping of a romantic rival.

The first report, by the independent panel in July, said: "Interviews with both flight surgeons and astronauts identified some episodes of heavy use of alcohol by astronauts in the immediate preflight period, which has led to safety concerns."

One instance involved a shuttle astronaut that a colleague claimed had had to much too drink; the colleague alerted others only after the launch was delayed because of mechanical problems.

O'Connor, using the clues in that report, focused on three missions between 1990 and 1995. He spoke to at least two astronauts on each of those missions and the astronaut chiefs at the time and no one verified the claims.

The other alleged incident involved an astronaut drinking alcohol before flying on a Russian Soyuz capsule to the international space station.

Drinking small champagne toasts is part of a "special ceremony" before cosmonauts go to the launch pad in Kazakhstan, O'Connor wrote. He reported that one non-drinking American worried about not imbibing, but was told by Russian flight surgeons it was OK not to drink.

In both cases — in which no names were given — the report said that flight surgeons and/or fellow astronauts raised safety worries with nearby officials in charge, yet "the individuals were still permitted to fly."

NASA administrator Michael Griffin this month pronounced prelaunch preparations for astronauts to be so visible that it is nearly impossible to sneak a drink.

"They would have to really want to drink and hide it really well," Griffin said before the launch of the shuttle Endeavour. He called the charges "uncredible."