An Operations Overview of the Hubble Space Telescope Servicing Mission 4

Abstract

With a final decision on the mission still pending, renewed preparations for a fifth Space Shuttle-based Servicing Mission (SM4) to the Hubble Space Telescope (HST) began in 2005. Since inception, HST was designed to be serviced, not only to refurbish or replace degraded and nonfunctional components, but also to infuse new technology into the Observatory. Over its 15-year span, HST has experienced all of the above cases. Its long life has necessitated the installation of new hardware such as a solid-state recorder, gyros, and instruments. At the same time, the spacecraft has pioneered technological advances in spacebased electronics and instruments. These advances range from a space-qualified 486 computer to state-of-the art imaging cameras and spectrographs spanning a range of wavelengths. For this upcoming servicing mission, HST will experience this two-fold process again with the replacement of hardware such as a new complement of six gyros, six new batteries, a refurbished fine guidance sensor, and three new outer blanket panels. Two new scientific instruments -Wide Field Camera 3 (WFC3) and Cosmic Origins Spectrograph (COS) will also be installed. With these improvements, the Observatory will continue to provide cutting edge capabilities with an extended lifetime well into the next decade. This paper will provide an overview of the planning and unique challenges of the SM-4 mission from an operational aspect, and describe in more detail the hardware to be installed. Additionally, the greatly expanded and unique scientific opportunities enabled by the installation of the new scientific instruments will be discussed.