DESIGN OF THE NASA LIGHTWEIGHT INFLATABLE SATELLITES FOR THE DETERMINATION OF ATMOSPHERIC DENSITY AT EXTREME ALTITUDES

Abstract : A design study was made of the characteristics of inflatable spheres for use as satellites for determining atmospheric density. The spheres could be fabricated from lightweight material, compactly folded, and inflated to give a large frontal area. The temperature of the inflatable sphere while in a sunlight orbit could be controlled by coating the outside surface of the sphere. A 12-foot-diameter inflatable sphere was successfully injected into orbit and named Explorer IX (1961 Delta 1). The inflatable satellite is optically visible and appears to reflect more like a specular sphere than a diffused sphere. Radar sightings of the satellite have indicated that the 12-foot-diameter satellite is fully inflated. (Author)