Jim Barnes: Say, Doc, the ship's about ready to take off, isn't she?
Dr. Charles Cargraves: Except for tests and minor adjustments.
Jim Barnes: Well, what's the next favorable time?
Dr. Charles Cargraves: About a month from now.
Jim Barnes: No, I don't mean that. What's the next favorable time this month?
Dr. Charles Cargraves: [checking the calendar] The only favorable time this month is about 17 hours from now.
Jim Barnes: All right, that's it then. We take off in 17 hours.
General Thayer: Are you out of your mind?
Jim Barnes: I will be, if we run into any more red tape! Now look, there's no law against taking off a spaceship: it's never been done, so they haven't got around to prohibiting it. If we ask for permission, they'll find a way to block us. So we go now, as soon as we can!
General Thayer: In an untested ship?
Jim Barnes: How do you test a thing of this kind? It either works or it doesn't.

General Thayer: On the Moon! Jim, Doc, we're on the Moon!
Joe Sweeney: And we're alive - holy cow! General, the next time you tell me you can get to the Moon, I'll believe you!

Dr. Charles Cargraves: You can't buck public opinion; I've tried. Have you seen this?
[Newspaper headline: MASS MEETING PROTESTS RADIOACTIVE ROCKET]
General Thayer: That isn't public opinion - it's a job of propaganda!
Jim Barnes: You're almighty right it is. Manufactured and organized - with money and brains. Somebody's out to get us.

[Experiencing spacesickness]
General Thayer: I know one thing: unless these pills work, space travel isn't going to be... popular.

[after stepping onto the Moon's surface]
Jim Barnes: Claim it, Doc! I'm your witness - claim it officially.
Dr. Charles Cargraves: By the grace of God, and the name of the United States of America, I take possession of this planet on behalf of, and for the benefit of, all mankind.