Fifty-four years ago this week, USAF Major David G. Simons, MD successfully completed the Manhigh II high-altitude balloon mission. Simons’ epic flight lasted 32 hours and established an altitude record of 101,516 feet.
Project Manhigh was a United States Air Force biomedical research program that investigated the human factors of spaceflight by taking men into a near-space environment. Preparations for the trio of Manhigh flights began in 1955. The experience and data gleaned from Manhigh were instrumental to the success of the nation’s early manned spaceflight effort.
The Manhigh target altitude was approximately 100,000 feet above sea level. A helium-filled polyethylene balloon, just 0.0015-inches thick and inflatable to a maximum volume of over 3-million cubic feet, carried the Manhigh gondola into the stratosphere. At float altitude, this balloon expanded to a diameter of about 200 feet.
The Manhigh gondola was a hemispherically-capped cylinder that measured 3-feet in diameter and 8-feet in length. It was attached to the transporting balloon via a 40-foot diameter recovery parachute. Although compact, the gondola was amply provisioned with the necessities of flight including life support, power and communication systems. It also included expendable ballast for use in controlling the altitude of the Manhigh balloon.
The Manhigh test pilot wore a T-1 partial pressure suit during the Manhigh mission. This would protect him in the event that the gondola cabin lost pressure at extreme altitude. The pilot was hooked-up to a variety of sensors which transmitted his biomedical information to the ground throughout the flight. This allowed medicos on the ground to keep a constant tab on the pilot’s physical status.
The flight of Manhigh I took place on Sunday, 02 June 1957 with USAF Captain Joseph W. Kittinger as pilot. Kittinger reached an altitude of 95,200 feet. Though successful in the main, the mission was cut short due to rapid depletion of the oxygen supply. This was caused by accidental crossing of the oxygen supply and vent lines prior to flight. Total mission time was 6 hours and 32 minutes.
Manhigh II was launched at 1422 UTC from Portmouth Mine in Crosby, Minnesota on Sunday, 18 August 1957. USAF Major David G. Simons, a medical doctor, flew this nominally 24-hour mission. Simons uneventful ascent to Flight Level 1,000 took 2 hours and 18 minutes. A maximum altitude of 101,516 feet was ultimately recorded during Manhigh II.
Simons’ flight was taxing both physically and mentally. Cabin environmental management issues and the frequent need to monitor and control atitude so as to remain sufficiently above thunderstorm activity were the primary stressors. However, the pilot dutifully went about conducting a variety of more than 25 different scientific experiments. Simon’s flight came to a successful conclusion when his gondola landed in an alfalfa field near Frederick, South Dakota at 22:32 UTC on Monday, 19 August 1957.
By way of postscript, Manhigh III was successfully conducted on Wednesday, 08 October 1958. Launch occurred at Holloman AFB, New Mexico with USAF Lt Clifton M. McClure as pilot. The mission’s success was largely due to McClure’s super-human efforts in overcoming a variety of life-threatening problems. However, that story will be reserved for another day.
The contributions made to aero medical science by the Manhigh Program were significant. Indeed, information gleaned from this flight research effort tangibly influenced future manned flight including the X-15 Program, Project Excelsior and Project Mercury. To get a fuller appreciation for Manhigh’s significance in aerospace history, the interested reader is invited to read Simons 1962 book aptly entitled “Manhigh”.
David Simons continued to serve his country as an officer in the United States Air Force for another 8 years following his Manhigh II flight. He retired from the junior service in 1965 as a Lieutenant Colonel. In civilian life, he went on to become an internationally-recognized expert in the treatment of chronic pain. In April of 2010, Simons left this frail existence while in his 88th year.