Structural distortions of space systems due to environmental disturbances

It is expected that the size and nature of satellites is likely to change as a result of the greatly enhanced launch capabilities of the space shuttle. Greater payload capability, manned assembly and maintenance will all contribute toward larger space platforms. Such larger platforms are expected to perform to higher levels. As a result, the disturbances, which tend to degrade the performance of these satellites, need to be known to a greater extent. This paper examines present approaches to environmental disturbance modeling and discusses the methods used to evaluate the resulting structural distortions. For the most critical loadings, such as thermal radiations, solar pressure, gravity gradient, and atmospheric drag, disturbance models and their limitations are described along with suggestions for reducing their impact. The modern discretization of the structures using a finite-element approach is explained as are the solution methods for both static and dynamic responses. Special attention is given to model analysis because of its advantage in interpreting structural behavior and reducing computational difficulties. When the performance goals are not met, the designer is faced with a wide range of options for improvement. Enhancement can be obtained by use of passive or active means of controlling the structural response. As the performance of new and larger satellites becomes increasingly demanding, it is recognized that both environmental-disturbance and supporting-structure modeling need to be enhanced. New analytical and computational tools must be developed to assess the intricate interactions between spacecraft and environment with increased confidence. Copyright @ 1980 by The Charles Stark Draper Laboratory, Inc. Published by the American Institute of Aeronautics and Astronautics with permission. *Member of Technical Staff. tGroup Leader, 601 Purchased from American Institute of Aeronautics and Astronautics