"The lack of privacy on launch day makes it nearly impossible to hide alcohol use or alcohol-induced impairment. Could a crewmember drink to the point of inebriation in his/her room the night before launch? Certainly, but, from the time the crew wakes on launch morning until they lift off, they are surrounded by other astronauts, managers, support crew, television (TV) cameramen, still photographers, crew quarters staff and others. Breakfast, the first scheduled event, usually starts 30 minutes after wakeup and is held in the same dining room shared by support crew and operational managers."
"The result of my tours and interviews was this: alcohol is available in the crew quarters, but is only used during off-duty hours. None of the people I talked to or heard from admitted to witnessing anything more than moderate use on L-2, light use on L-1, and none at all on launch day before cabin ingress or scrub."