[Leonard McCoy sits down next to James T. Kirk on a shuttle]

I may throw up on you.

I think these things are pretty safe.

Don't pander to me, kid. One tiny crack in the hull, and our blood boils in thirteen seconds. Solar flare might crop up, cook us in our seats. And wait till you're sitting pretty with a case of Andorian shingles. See if you're still so relaxed when your eyeballs are bleeding! Space is disease and danger wrapped in darkness and silence.

Well I hate to break this to you, but Starfleet operates in space.

Yeah, well, I got no where else to go. The ex-wife took the whole damn planet in the divorce. All I got left is my bones.