Overcoming adversity in instrument operations anomalies

The Cassini-Huygens mission to Saturn launched in October 1997. The Cassini Plasma Spectrometer (CAPS) is an in-situ instrument and is one of 12 instruments on the orbiter. Cruise science (beyond instrument checkout periods and periodic maintenance) was approved, and over 870 days of data were collected prior to the start of the prime mission. Prime mission operations started in January 2004 and continued through end of June 2008. Given the success of the Cassini mission at Saturn, an extended mission, the Equinox Mission, was approved for an additional two years, ending September 2010. The continuing success of the Equinox mission led to approval of a second extended mission called the Solstice Mission. The Solstice mission has approval through September 2012 with pending approval through July 2017. The Cassini Plasma Spectrometer (CAPS) has generated a wealth of science data and we have over 240 publications. In addition, the CAPS scientists participate in conferences, inter-team collaborations, and community outreach. Collection of data has not been without instrument related challenges. This paper will discuss a few of the in-flight instrument related anomalies experienced by CAPS including timing difference between the engineering model and the flight model, actuator related anomalies, and a latched bit. The analysis will cover how the anomalies were discovered, the techniques used to diagnose the problems in-flight, fixes that were implemented, how the anomalies affected operation of the instrument and collection of science, and lessons learned from the process.