Air Renewal
Re-oxygenating the air within the projectile spacecraft.

Columbiad - 900 foot cannon
An enormous cannon, sufficient in size to send a projectile to the Moon.

Communicate with Extraterrestrials - first use of concept
Early plan to communicate with life on planets removed from the earth.

Free Return Trajectory - first mention
The idea that it would be possible for a projectile to go around the Moon and then return to Earth.

Gourmet Space Cuisine
The finest in French cuisine, in outer space.

Launching Facility - in Florida
A specific spot with support for a space launch.

Light Pressure Propulsion - first use of this idea
First mention of the idea that light itself could be a form of propulsion for spacecraft.

Projectile-Vehicle - Verne's spacecraft
A projectile, or shot, capable of enclosing passengers and being safely hurled to the moon by an enormous cannon.

Retro-Rockets - Verne invented them!
Small boosters to provide a thrust counter to the current velocity of the spacecraft, slowing it down or stopping its progress altogether.

Splashdown - the original idea
The use of water as a medium for landing one's space ship in.

Water-Springs
Using water to cushion the living space of a spacecraft from the effects of acceleration.

Weightlessness - true science fiction discovery
The state experienced in free fall; a space traveler's weight is apparently reduced to zero.