In addition to unmanned high altitude balloon research flights, from 1957 to 1962 the U.S. Air Force conducted a series of seven manned high altitude flights. These forward-looking projects investigated the upper reaches of the earth’s atmosphere and laid the foundation for manned spaceflight. Most flights were conducted before rocket booster technology was available to propel a spacecraft into earth’s orbit. In this interim period, to “bridge the gap” while awaiting developments in rocket technology, high altitude balloons were the only vehicles capable of reaching the altitudes required. All three of the USAF manned high altitude balloon projects, MAN HIGH, EXCELSIOR, and STARGAZER utilized Holloman AFB balloons to transport men to the very edge of space, above approximately 99 per cent of the earth’s atmosphere, a region known as “near space.” =Project MAN HIGH.= In 1955, a combined effort by the U.S. Air Force Aeromedical Field Laboratory, Winzen Research International, and the Holloman Balloon Branch resulted in the first Air Force manned balloon program. Project MAN HIGH, officially known as the Biodynamics of Space Flight, directed by Lt. Col. David Simons (MC), was the first of the three widely publicized manned high altitude balloon programs. The objective of Project MAN HIGH was to measure the physiological and psychological capabilities of a human in a space equivalent environment. Many developments of this successful project were later incorporated into the first phase of the U.S. Air Force Man in Space Program nicknamed MAN IN SPACE SOONEST (MISS). Technology developed for MISS was transferred to NASA in 1959 and became part of Project MERCURY, the initial series of U.S. space missions.[167] [Illustration: Fig. 11. (_Left_) Test pilot Capt. Joseph W. Kittinger, Jr. just before launch of MAN HIGH I at New Brighton, Minn. on June 2, 1957. Kittinger flew in all three USAF high altitude balloon projects and has accumulated more high altitude balloon flying hours than anyone else in the world. (_U.S. Air Force photo_)] [Illustration: Fig. 12. (_Center_) Lt. Col. David G. Simons (MC), a physician and pilot of the MAN HIGH II high altitude balloon mission, is shown here boarding the recovery helicopter near Frederick, S.D. following the successful flight on August 19, 1957. This flight lasted 33 hours and 10 minutes attaining a peak altitude of 101,500 feet. (_U.S. Air Force photo_)] [Illustration: Fig. 13. (_Right_) Holloman AFB Balloon Branch Meteorologist and Engineer, Bernard D. Gildenberg, instructs high altitude balloon pilot 1st Lt. Clifton McClure, pilot of MAN HIGH III, in the operation of a low altitude training balloon on May 12, 1959 at Holloman AFB, N.M. (_U.S. Air Force photo_)]