Cassini Spacecraft Events and Configuration Information

Spacecraft Noise Sources

Certain spacecraft events affected how Cassini gathered science data. For example, many of these events generated noise that affected the ability of the instruments on the spacecraft to properly collect science data. In addition, other events required that some of the instruments be turned off for the duration of the event. Finally, a third set of events, such as a change in the mass of the spacecraft, impacts data analysis. Below are the various noise sources and spacecraft events that have bearing on finding and analyzing science data.

MAG Science Calibration Subsystem (SCAS) Sensor Alignment Determination [TXT]

The orientation of the magnetometer sensors with respect to the spacecraft may change slightly after events such as spacecraft maneuvers or as the thermal environment changes with distance from the sun. The SCAS is a means of determining the magnetometer sensor alignment.
See the README for more information.

MIMI INCA Discharges

These discharges do not appear to have any measurable effect on the quality of the MIMI science data. They do, however, result in interference in the RPWS plasma wave data.
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
See the README for more information.

RPWS Sounder Firings [TXT]

This deliberate electromagnetic signal may interfere with other science observations. Specifically, CDA may misinterpret a sounder pulse as a dust detection.
See the README for more information.

Solid State Power Switch Trips [PDF] [XLSX]

Spacecraft Configuration Information

SOI Command Timeline [PDF] [DOCX]

See the README for more information.

Main Engine Cover Actuations [TXT] [PDF] [XLSX]

There were 97.5 cover cycles during flight.
See the README for more information.

Navigation Information

Doppler and Range Tracking Data

This is the Doppler and range data used by the navigation team to determine Cassini’s orbit. TDM’s are text files formatted according to international standards.

Earth orientation parameters

This file describes a rotation from an Earth-fixed reference frame to an inertial reference frame. It is used to convert tracking station locations (Earth-fixed coordinates) into the 'radio' frame (inertial coordinates) needed to process Doppler and range measurements.

Media Calibrations

These files contain troposphere and ionosphere calibrations used to model the effect of Earth's atmosphere on Doppler and range measurements. They span Cassini's tour phase.

DSN Interstation Clock Offsets

This file describes clock differences between DSN complexes during times when '3-way' Doppler tracking is acquired. It is used to calibrate Doppler measurements uplinked from one DSN complex and received at a different complex. The file also contains a few corrections to range measurements. In these instances, the file contains adjustments for range calibrations that were incorrectly reported on the Doppler and range tracking data file. The file spans Cassini's tour phase.

Small Force History

This file contains a list of propulsive events required for attitude and articulation control management. It includes the time of the events and predicted delta-V's imparted to the spacecraft. It spans Cassini's tour phase.

Maneuver History

This file contains a listing of all the trajectory correction and orbit trim maneuvers performed by Cassini. It provides maneuver times and delta-V magnitudes.

Gap Report

Many tables provided on this site are "as-planned", meaning that they represent the initial science-planning time tables. For various reasons, data might not be delivered even though an observation was planned. For example, weather conditions at the Deep Space Network may have blocked communications during downlink, and data would therefore be lost. The gap reports below describe these time periods when data was either not gathered or was lost. If an observation that you are expecting to find has "gone missing", this can help explain the reason why.

For questions and comments, visit the PDS Cassini Contact Page