Dr. Simons received his medical degree at Jefferson Medical College, Philadelphia, Pennsylvania in 1946 and served his internship at Lancaster General Hospital, Lancaster, Pennsylvania in 1947. Simons entered the U.S. Air Force in 1947 and was assigned to the USAF Aeromedical laboratory at Wright-Patterson Air Force Base. From 1948 to 1949, He was Project Officer for Animal Studies in V-2 rocket flights to high altitudes.
From 1953 to 1959, Simons was Chief of Space Biology at the AF Missile Development Center at Holloman Air Force Base, New Mexico. During that time, he was Project Officer on Project 7851 which included high altitude balloon flight experiments studying cosmic radiation effects, weightlessness and space equivalent conditions.
Project Manhigh was established in December 1955 to obtain scientific data on the behavior of a balloon in an environment above 99% of the earth's atmosphere and to investigate cosmic rays and their effects on man. Three balloon flights to the edge of space were made during the program: Manhigh 1 to 29.6 km, by Captain Joseph Kittinger on 2 June 1957; Manhigh II to 30.95 km, by Major David Simons on 19 and 20 August, 1957; and Manhigh III to 29.9 km by Lieutenant Clifton McClure on 8 October 1958.Including the pilot and scientific equipment carried aboard, the total weight of the Manhigh II gondola was 747 kg. At maximum altitude, the balloon expanded to a diameter of 60 m with a volume in excess of 85,000 cubic m.
