Hubble Space Telescope Solar Array Concerns and Consequences for Servicing Mission 2

Abstract

Designed for the launch and subsequent on-orbit maintenance by astronauts and the Space Shuttle, the Hubble Space Telescope presented a unique and challenging set of flight operations issues during six missions between 1990 and 2009. Starting with the launch in 1990 and for the following three servicing missions, the solar arrays represented an unanticipated and significant operational challenge for the crews and the flight operations teams. Modified first-generation solar arrays were installed on Servicing Mission 1 in 1993 to correct for a jitter introduced into the telescope’s control system by the design of the original solar arrays. However, although the jitter was improved, the modified solar arrays introduced additional issues for the second servicing mission, Space Transportation System 82, due to the existence of a significant static twist. New flight operations techniques had to be developed to monitor the condition and protect the integrity of the solar arrays. It was not known until after Hubble Space Telescope capture whether the planned servicing tasks could be executed. However, the success of Servicing Mission 2 led to the adoption of similar techniques for use during subsequent Space Shuttle missions to the Hubble Space Telescope and to the International Space Station.