On June 27, 1963, he flew the X-15 to an altitude above 50 miles, thereby qualifying as an astronaut according to the United States definition of the boundary of space. However, this altitude did not surpass the Kármán line, the internationally accepted boundary of 100 kilometers (62 miles).
Following his graduation from the U.S. Air Force Institute of Technology in 1954, Rushworth stayed at Wright-Patterson Air Force Base in Dayton, Ohio. Among his duties was to serve at the Directorate of Flight and All-Weather Testing. There he specialized in the development and flight testing of experimental automatic flight control systems. He graduated from the Air Force Experimental Flight Test Pilot School (Class 56C) in 1957, flying F-101 Voodoos, F-102 Delta Daggers, F-104 Starfighters, F-105 Thunderchiefs, F-106 Delta Darts and other jet fighters. Rushworth was selected for the X-15 program in 1958. He made his first flight on November 4, 1960. Over the next six years, he made 34 flights in the X-15, the most of any pilot. This included a flight to an altitude of 285,000 feet, made on June 27, 1963. This flight above 50 miles qualified Rushworth for Astronaut Wings, though he would have attained that honor sooner had the USAF Man In Space Soonest project proceeded according to plan.
At the time of his retirement as a major general, he was vice commander, Aeronautical Systems Division, Air Force Systems Command, at Wright-Patterson Air Force Base, Ohio, where he dealt directly with senior deputies and managers and assisted the management of major acquisition programs such as the F-5, A-10, F-15, F-16 and B-1 as well as numerous modernization programs like the B-52 and C-5. He held this position since October 1976.
Rushworth was a fellow of the Society of Experimental Test Pilots (SETP), and in 1975 received the SETP's James H. Doolittle Award for "outstanding accomplishment in technical management or engineering achievement in aerospace technology". Rushworth retired on June 1, 1981.
He was rated a Command Pilot Astronaut and logged over 6,500 flying hours in more than 50 types of aircraft.[6]
Personal
Rushworth married Joyce Butler (1925–1980) in June 1947, and they had one daughter, Cheri (born March 29, 1957).[7] He died of a heart attack in Camarillo, California, on March 18, 1993, at the age of 68. He is buried at Forest Hill Cemetery in his hometown Madison, Maine.[8][9]
Awards and honors
"God, I don't understand it. Here's a guy hitchhiking to Vietnam."
—A general officer about Rushworth's intentions to go into combat in Vietnam.[10]
^"California Death Index, 1940–1997," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:VPZY-79C : 26 November 2014), Robert Aitken Rushworth, 18 Mar 1993; Department of Public Health Services, Sacramento.