Next Generation Space Telescope. I: Design Considerations

Abstract

The pointing control system of the Hubble Space Telescope (HST) represents the current state of the art for the precision control of a large spacecraft. The proposed Next Generation Space Telescope (NGST) will require an order‐of‐magnitude increase in pointing resolution over that of HST. The use of active optics in the form of a steerable secondary mirror has been proposed for NGST in order to satisfy these requirements. An introduction to some of the design concepts associated with the design of the NGST, including a description of the proposed vehicle, a description of the pertinent design parameters, and a description of the types of disturbances to which it may be subjected, is given herein. A companion paper provides a description of a feasibility study conducted to evaluate the use of a control system for the implementation of “beam steering” to compensate for the motion of the vehicle without necessitating the reorientation of the whole structure.