NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Cassini at Saturn Proximal Orbits - Attitude Control ChallengesThe Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.
Document ID
20150007833
Document Type
Conference Paper
External Source(s)
Authors
Burk, Thomas A. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 11, 2015
Publication Date
August 19, 2013
Subject Category
Lunar and Planetary Science and Exploration
Meeting Information
2013 AIAA Guidance, Navigation, and Control Conference(Boston, MA)
Distribution Limits
Public
Copyright
Other
Keywords
Huygens