NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Reducing Pointing Errors During Cassini Reaction Control System Orbit Trim ManeuversThe effect of altering a gain parameter in the Cassini reaction control system (RCS) delta-V controller on the maneuver execution errors during orbit trim maneuvers (OTMs) is explored. Cassini consists of two reaction control thruster branches (A & B) each with eight thrusters. Currently, the B-branch is operational while the A-branch serves as a back-up. The four Z-thrusters control the X and Y-axes, while the four Y-thrusters control the Z-axis. During an OTM, the Z-thrusters fire to maintain the X and Y-axes pointing within an attitude control dead-zone (-10 to 10 milliradians). The errors do not remain at zero due to pointing error sources such as spacecraft center of mass offset from the geometric center of the Z-facing thrusters, and variability in the thruster forces due to the thruster hardware differences. The delta-V reaction control system (RCS) controller ensures that the attitude error remains within this dead-zone. Gain parameters within the RCS delta-V controller affect the maneuver execution errors. Different parameter values are used to explore effect on these errors. It is found that pointing error decreases and magnitude error increases rapidly for gain parameters 10 times greater than the current parameter values used in the flight software.
Document ID
20150007830
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Rizvi, Farheen
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 8, 2015
Publication Date
August 19, 2013
Subject Category
Lunar And Planetary Science And Exploration
Space Communications, Spacecraft Communications, Command And Tracking
Spacecraft Instrumentation And Astrionics
Meeting Information
Meeting: 2013 AIAA Guidance, Navigation, and Control Conference
Location: Boston, MA
Country: United States
Start Date: August 19, 2013
End Date: August 22, 2013
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Other
Keywords
European Space Agency (ESA)
orbit trim maneuvers (OTMs)
flyby
Cassini-Huygens mission

Available Downloads

There are no available downloads for this record.
No Preview Available