The United States Air and Space Force was the air and space arm of the armed forces of the United States of America. This force was the successor of the older, less modern (compared to the technology of the Race) US Army Air Force. It was created out of the need to be on an equal footing with the Race, military-wise. During the Invasion itself, when American pilots flew in prop-driven aircraft against the Race's killercraft, the average pilot's life expectancy was measured in hours. Many pilots survived only due to having injuries, as in the case of Glen Johnson.