Cassini Spacecraft Attitude Control System Performance and Lessons Learned, 1997–2017

Abstract

A sophisticated interplanetary spacecraft, Cassini–Huygens was launched on 15 October 1997. After achieving orbit at Saturn in 2004, Cassini collected science data throughout its four-year prime mission (2004–2008) and nine-year extended mission (2008–2017). The Cassini Attitude and Articulation Control Subsystem (AACS) is perhaps the spacecraft subsystem that must satisfy the most mission and science pointing requirements. The performance of the Cassini AACS design was superb from launch through end of mission. All key mission and science requirements were met with significant margins. Overviews of the Cassini attitude control system design and flight performance (in 1997–2017) are given in this paper. Processes taken by the attitude control operations team to guard against human errors are also outlined. Cassini flight experience and many lessons learned are equally applicable to the safe operations of other interplanetary missions.