Optical Problems of the Satellite

Some of the optical problems connected with an artificial earth satellite are: visibility, the photographic determination of the precise orbit, and the temperature that the satellite will reach through radiation exchange. These matters are discussed with particular reference to the plans for the satellites to be launched by the United States during the International Geophysical Year. One of the first experiments to be flown will be the monitoring of the Lyman alpha line radiation of hydrogen emitted by the sun and the measurement of intensity variations associated with solar flares.