Why Satellites Stay in Orbit is another of these very simple factual books for children. By taking one fact or phenomenon, the story can expand to explain it in simple terms with many examples.
Engelbrektson, Sune. Illustrated by Ames, Lee. Why Satellites Stay in Orbit? New York: Holt Rinehart and Winston Inc. (26 p.) (1964)
A very basic book on gravity using satellites and space craft as examples. Includes Illustrations of satellites, rockets and the Earth from space.
These books are exactly why I started collecting children's non-fiction about space. When they became out of date they were discarded. However they represented a kind of peak in science education and are interesting to remember.