Living organisms possess many unique processes and systems which are complex and poorly understood. The new theoretical approaches, combined with laboratory studies, are expected to result in advances which will expand both our scientific and technological horizons. chapter 6 _Flight Programs_ BALLOONS Biological and medical experiments carried out on balloon flights, both manned and unmanned, antedate the establishment of NASA. Aside from the early use of balloons in flights that could be called simply flight-survival studies, balloons have made important contributions to our present knowledge of the effects of cosmic radiation and to various aspects of space travel. The achievements of the Strato-Lab and Man High series by the U.S. Navy and Air Force include a wealth of information on balloon travel and on the survival of man at altitudes close to and above 100 000 feet. Generally, balloon launches of animals, which reached a maximum in 1953 when 23 balloons were released, have established the feasibility of a program of extended manned balloon flights to high altitudes. Atmospheric life studies outside the area of cosmic radiation effects have been comparatively few. Results from two manned flights, Strato-Lab I and II, indicate that the flights did produce pronounced changes in white blood cell count; however, the data suggest that these changes were due to psychological rather than physical stress. Exposure to altitudes above 90 000 feet for a total of 62 hours did not produce any general behavioral change in two Java monkeys, according to other balloon flights. Many of these flights were effective in testing equipment, telemetering devices, and in pointing the way for other flights. Stratoscope I and II, originally undertaken by the Office of Naval Research (ONR), are projects involving various astronomical observations with the aid of a balloon-borne telescope and television and camera systems. NASA cooperated with ONR on Stratoscope II (36-inch telescope compared with Stratoscope I’s 12-inch telescope) which has already resulted in significant discoveries about the nature of the planets and stars. Water vapor has been identified in the atmosphere of cool red stars and an analysis of the Martian spectra showed a greater abundance of carbon dioxide than had previously been believed. Since the balloon-borne telescope was carried beyond Earth’s obscuring atmosphere, the Stratoscope projects have yielded valuable photographs of the Sun, stars, and various planets. ROCKETS AND SATELLITES