NASA was established in 1958, shortly after the Russian launching of the second Earth satellite Sputnik II, the first vehicle to carry life into orbit around the Earth. This accomplishment was preceded by the pioneering work of Henry et al. ([ref.77]), in which animals were exposed briefly to low-gravity states in Aerobee rockets. A motion-picture camera photographed the behavior of two white mice in rotating drums during this series of flights, which marked the first time that simple psychological tests were made on animals in the weightless condition. While this behavioral experiment was relatively simple, it provided the basic concepts for recent studies which involved rotation of animals during the weightless state. Subsequent flights such as Project MIA (Mouse-in-Able) reflected a preoccupation with physiologic measures (refs. [ref.78] and [ref.79]), although the flights of Baker and Able included preflight and postflight performance studies ([ref.80]). Able’s behavior was recorded in detail on in-flight film, but none of the behavior was programed or under experimental control. The first flights in which behavior or performance was explicitly programed were those of Sam and Miss Sam in flights of the Little Joe rocket with the Mercury capsule, launched from Wallops Island in 1959 and 1960 ([ref.81]). The first major space achievement in the behavioral sciences was the successful in-flight measurement of the behavior of the chimpanzee Ham in early 1961, in which the pretrained animal performed throughout the flight. The second achievement along these lines was in 1962 when the chimpanzee Enos made several orbits around Earth and performed continuously on a complex behavioral task. The tasks which the animals performed during these flights have been described in detail by Belleville et al. ([ref.82]), and the results of the in-flight performance have been presented by Henry and Mosely ([ref.83]). These early flights provided much of the technological framework on which current biological experiments on organisms during flights of extended duration are based. Due largely to the efforts of Grunzke (refs. [ref.84] and [ref.85]), the apparatus needed to sustain animals during space flight, such as zero-g watering and feeding devices, are now commonplace ([ref.86]). Advanced systems of programing stimulus presentations and recording responses, developed for Project Mercury, may now be seen in many basic research laboratories throughout the country.