Born in Berlin, Ehricke believed in the feasibility of space travel from a very young age, influenced by his viewing of the Fritz Lang film Woman in the Moon.

[2] He worked at Peenemünde as a propulsion engineer from 1942 to 1945 with Walter Thiel,[1] then went to the United States with other German rocket scientists and technicians under "Operation Paperclip" in 1947.

His lunar industrialization concept was based on the most advanced technologies, such as nuclear-powered freight transporters, and using fusion energy to power his city, Selenopolis, on the Moon.

Although he was not the first, he clearly demonstrated the so-called "gravity assist" method for utilizing hyperbolic encounters with an intermediate planet to increase (or decrease) the velocity and orbital elements of a space vehicle.

This idea refers to Ehricke's belief that it was the responsibility of humanity to explore space and exploit the resources of the Solar System, in order to sustain the development of the species.

There are no external "limits to growth," Ehricke insisted, because while the Earth is a "closed system," the exploration of space opens the universe to humanity.