His collection, Mars Mountain (1935) was the first full-length book to be issued by a publisher that specialized in science fiction.
Key was an associate professor of engineering at East Los Angeles College.
Key was a licensed professional engineer, and had varied and extensive practical experience as an engineer and mechanical designer in private industry and for government agencies.
He had the rank of lieutenant colonel in the United States Air Force Reserve, and while on active duty during World War II, he wrote and edited technical handbooks for the Air Force.
Key was also a member of the American Society of Civil Engineers and Architects, the National Science Teachers Association, the American Society for Engineering Education, and the Los Angeles College Teachers Association, and was listed in The International Yearbook and Statesman's Who's Who, Who's Who in the West, and Who's Who in Commerce and Industry.