After White Sands, Stine was employed at several other aerospace companies, finally ending up at Martin working on the Titan project.

In his "The Formative Years of Model Rocketry, 1957–1962; A Personal Memoir" (International Astronautical Federation, IAF XXVIIth Congress, Anaheim, CA, October 10–16, 1976 (76-241), he wrote "I was fired by the Martin Company on October 5, 1957, for telling United Press that the Soviets had used their ICBM as a launch vehicle (which they had), that Sputnik meant that the entire United States was open to nuclear ICBM attack (which it still is), and that the United States was not first in space because we did not have a serious space program (which we did not under the Eisenhower administration).

Shortly thereafter he received a letter from Orville Carlisle, who had begun making small models and, more importantly, replaceable solid fuel engines to power them.

Stine continued to work to popularize the hobby, writing the Handbook of Model Rocketry in 1965, which went on through seven editions over the years.

He returned to the aerospace industry, continuing to write under his pen name, including a Star Trek novel called The Abode of Life and the original novel Shuttle Down.

He was a consultant to CBS News during the Apollo program, along with Lindy Davis, Charles Friedlander and Richard C. Hoagland.

Stine was very interested in the interaction of volunteer/free market Libertarian ideas with space colonization and as a tool of citizen diplomacy and world peace, and so was called to serve as Chair of the Advisory Board of the Libertarian International Organization where he mentored various citizen initiatives until his death.