Cassini Significant Events 10/20/10 – 10/26/10

The most recent spacecraft telemetry was acquired on Oct. 25 from the Deep Space Network tracking complex at Madrid, Spain. The Cassini spacecraft is in an excellent state of health and all subsystems are operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" page at: http://saturn.jpl.nasa.gov/mission/presentposition/ .

Wednesday, Oct. 20 (DOY 293)

This week's science observations included the completion of a 44 hour interstellar dust campaign by the Cosmic Dust Analyzer (CDA). Imaging Science (ISS) performed another observation in its Satellite Orbit Campaign as well as a 4.5 hour observation of the moon Hyrokkin. The Composite Infrared Spectrometer (CIRS) performed a mid-infrared (IR) stellar spectroscopy measurement of the star Eta Carinae, followed by an eight-hour stray light calibration, and completed its 28.5-hour mid-IR map of Saturn to determine upper troposphere and tropopause temperature. The Visual and Infrared Mapping Spectrometer (VIMS) continued its 37-hour exoplanet transit observation of the K dwarf star HD 189733. This star has a planet that transits the star every 2.2 days with transit duration of 1.6 hours. During the transit, the flux from the star is expected to decrease by ~3 percent.

Thursday, Oct. 21 (DOY 294)

The Spacecraft Operations Team performed the first in a series of real time commands today to load the Attitude and Articulation Control Subsystem (AACS) flight software (FSW) version 8.8.0 to the spacecraft. It will take four DSN passes and be completed on Oct. 27.

The command loss timer value was restored to the nominal value of 110 hours today.

Friday, Oct. 22 (DOY 295)

AACS Periodic Engineering Maintenance was completed today. This activity, performed approximately every 90 days, exercises the main engine gimbal actuators, the backup reaction wheel assembly - or RWA-3 - and scrubs the Backdoor Assisted Load Format Injection Loader memory.

Sunday, Oct. 24 (DOY 297)

Commands were radiated over Madrid's DSS-63 today in support of the Magnetospheric Imaging Instrument (MIMI) ion and neutral camera high voltage test, and will start executing on the spacecraft on Nov. 3.

Monday, Oct. 25 (DOY 298)

A week-long series of presentations and discussions at the 52nd meeting of the Cassini Project Science Group begins today. Topics will focus on the objectives for the Solstice Mission and expected challenges with the transition to this mission phase, as well as science results to date.

A talk titled "Tiger Stripes and Pac-Men: Update on Cassini Thermal Observations of Enceladus and Mimas" was given today by a Cassini CIRS team member. This event was part of the Division 32 Science Colloquium Program.

Cassini personnel continue to support the office moves and reconfigurations within the Project area. This is an ongoing task which will continue through next month, and is driven by the Project's transition to the new, descoped Solstice mission. The Cassini portal web pages and links continue to be updated to reflect the new Solstice Mission organization.

Cassini once again supported telemetry testing of the new DSN Data Capture and Delivery (DCD) software by participating in a second DCD-DSN Project Interface Test (PIT) today. Instrument Operations (IO) - IO/ISS and IO/VIMS - participated in the test to compare data throughput and timing to that received via the current operational interface.

Tuesday, Oct. 26 (DOY 299)

Port 3 products were due today as part of the S67 Sequence Implementation Process (SIP). The products will be merged and sent out to the flight team for review.

Reaction Wheel Assembly (RWA)-1 low rpm test #2, the second of three planned tests, took place tonight. RWA-1 was set to +400 rpm for a period of about six hours to characterize behavior at this wheel speed. Preliminary results looked good, but analysis to help assess the cause of drag spikes is ongoing.