Sources

Sources:

https://www.nasa.gov/ : Information and images regarding the Apollo project.

http://galileoandeinstein.physics.virginia.edu/lectures/newton.html : Newton's Cannon picture.

http://www.astronautix.com/ (Encyclopedia Astronautica) : Information on rockets and the Apollo program.

https://what-if.xkcd.com/58/ : Space is/isn't like this.

Wikimedia Commons : Various illustrations.