The year is 1956. Mankind stands at the dawn of a new age, the Space Age, when the flying bombs of yesteryear will become the rocket ships of tomorrow. As the director of a national space program, your country is depending on you for success in this great contest. You may be the first to create an artificial satellite, send a probe to another planet, or even put a man on the moon.

Leaving Earth is a game about planning and about managing risk. With even a single grand journey into outer space, you might claim victory in the game. Consequently, it is your job to plan each journey carefully, finding the cheapest, quickest, and safest ways to reach your objective—but do not spend too long preparing, or another nation might reach its goal before you.

On your turn, you will be conducting research, building spacecraft, and directing journeys into outer space. To conduct research, you buy an advancement that begins with certain flaws, then you test the advancement to find and eliminate those flaws. To build a spacecraft, you purchase components and assemble them into a whole. To travel to outer space, you expend rockets to maneuver from one location to another.