A glider pilot and engineer before the war, he joined the Luftwaffe and became a test pilot at Peenmuende, making 37 test flights of the Me-163 rocket fighter and its unpowered prototypes. He survived a crash landing which resulted in the partial destruction of the aircraft as its airframe was consumed by the acid rocket propellants. After the war he surrendered to the Americans, and by January 1947 was working at Wright Field, Ohio. He became the Chief of Flight Development Section at Wright Field, before leaving to work for Aerospace Corporation as a consultant for the space program in 1957. He worked on both Mercury and Gemini programs. He authored two publications along with noted scientist Joseph F. Wambolt.
The ASPO Manager's proposal resulted from experience that had arisen because of unfortunate terminology used to designate the extra fuel. Originally the fuel budget for various phases of the mission had been analyzed and a 10 percent allowance had been made to cover - at that time, unspecified - contingencies, dispersions, and uncertainties. Mistakenly this fuel addition became known as a "10% reserve"! John P. Mayer and his men in the Mission Planning and Analysis Division worried because engineers at North American, Grumman, and NASA had "been freely 'eating' off the so-called 'reserve'" before studies had been completed to define what some of the contingencies might be and to apportion some fuel for that specific situation. Mayer wanted the item labeled a "10% uncertainty."
Shea recommended also that the capacity of the LEM descent tanks be sufficient to achieve an equiperiod orbit, should this become desirable. However, the spacecraft should carry only enough propellant for a Hohmann transfer. This was believed adequate, because the ascent engine was available for abort maneuvers if the descent engine failed and because a low altitude pass over the landing site was no longer considered necessary. By restricting lunar landing sites to the area between ±5 degrees latitude and by limiting the lunar stay time to less than 48 hours, a one-half-degree, rather than two-degree, plane change was sufficient.
In the meantime, Shea reported, his office was investigating how much weight could be saved by these propellant reductions.