From the operations point of view, by the spring of 1961 the equipment had been checked out and the basic guidelines followed. Existing technology and off -the-shelf equipment had been used where practicable; the simplest and most reliable approach to system design had been followed; an existing launch vehicle would be used to place the spacecraft in orbit and a progressive and logical test, program had been conducted.38 This had included test flights beginning as early as September 9, 1959, when a boilerplate spacecraft was successfully launched on an Atlas (Big Joe) from Cape Canaveral to test the validity of the Mercury concept.
In October and November of that year, Little Joe 1 and Little Joe 2, respectively, were fired from NASA's Wallops Station, Va., to test other aspects of the program. On December 4, 19591 Little Joe 3 was also fired from Wallops Station to check high-altitude performance of the escape system, with rhesus monkey Sam used as a test subject. The next month, on January 21, 1960, Little Joe 4 was fired from Wallops Station to evaluate the escape system under high airloads with another rhesus monkey—Miss Sam—as a test subject. These were followed by a beach abort test on May 9, 1960, and by an unsuccessful shot of the Mercury-Atlas 1 on July 29, 1960. Little Joe 5, also unsuccessful, was fired from Wallops Station on November 8, 1960.
Mercury-Atlas 2 was launched on February 21, 1961 (discussed in detail in the following chapter), and Little Joe 5A on March 18, 1961. On April 25, 1961, Mercury-Atlas 3 was launched in an attempt to orbit a "mechanical" astronaut. Forty seconds after launching, the launch vehicle was destroyed, but the spacecraft was recovered. Little Joe 5B was fired on April 28, 1961, and represented the third attempt to check the escape system under the worst possible conditions. The shot was successful.
Thus, by the spring of 1961, STG was prepared, from the engineering and operations point of view, for the projected Mercury-Redstone 3 flight scheduled for early May. It would carry the first American astronaut ona ballistic flight path. This would be prelude to the first U.S. manned orbital flight.39
Meanwhile, medical support plans for the launching, tracking, and recovery of the astronaut continued. The time and talent contributed by key medical personnel in the services as well as by the day-to-day working-level group is immeasurable. For example—to name only two—Brig. Gen. James W. Humphrys (MC), USAF, commander of the USAF Hospital at Lackland Base, and Brig. Gen. Don C. Wenger, then Deputy Director of Professional Services in the USAF Office of the Surgeon General, were to make themselves available at the shortest notice whenever professional problems arose in connection with planning. Later, as the actual flights were scheduled, they were there at the launch site during the long countdowns, postponements, flights, and recovery. This was part of the pattern carried out not only "in line of duty" but because every element of the military medical profession, no less than the civilian, shared in this most extensive peacetime effort of mobilization.
38. Walter C. Williams, Kenneth S. Kleinknecht, William M. Bland. Jr., and James H. Bost, "Project Review," in Mercury Project Summary Including Results of the Fourth Manned Orbital Flight, May 15 and 16, 1963. NASA SP-45, 1963, p. 2.
39. Manned Space Plight Program of the National Aeronautics and Space Administration: Projects Mercury, Gemini, and Apollo. Staff Report of the Senate Committee on Aeronautical and Space Sciences, Sept. 4, 1962, pp. 52-53.