He was a prolific author of books and articles on spaceflight and its history. Among his articles, my favorite is "2001: A Space Odyssey in Retrospect," p. 47-105 in the 1982 book Science Fiction and Space Futures, edited by Eugene M. Emme. This is a memoir of his work on the epic movie, chiefly concerned with wrangling its science and technology.
As I have previously written:
[Arthur] Clarke urged Kubrick to hire Ordway and his artist pal Harry Lange, and soon they were moving to England.
Ordway served as jack-of-all-space on the research and design of all the sets, models, etc. "I wasn't an expert on hibernation, but I knew who was. I wasn't an expert on food in space, but I knew people who were." He traveled around to various companies and universities, and got expert advice about future possibilities in the technologies the film would portray. [...]
"Everything had to work. We didn't know where Stanley would point his camera. It could be anywhere on the set." For this reason, every button and display in the spacecraft has a plausible function, every bump and knob on the spacesuits has a reason for its appearance.
One can hear Fred Ordway speak in a number of clips on Youtube.
"Science on Screen" talk following a showing of 2001 at the Belcourt Theatre in Nashville, Tennessee in March 2014.
From SpacePod, a 2010 three-part interview about The Rocket Team, Ordway's influential book with Mitchell Sharpe. It's about the German engineers who developed the V-2 missile during World War II, and went on to build ballistic missiles for the U.S. Army and Saturn Vs for NASA:
Ordway on the history of the National Space Society. He was a charter member of its ancestor, the National Space Institute, and served on NSS's Board of Governors.