NASA Cassini Significant Events for 10/22/08 – 10/28/08

The most recent spacecraft telemetry was acquired on Oct. 28 from the Deep Space Network tracking complex at Canberra, Australia. 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/operations/present-position.cfm.

Wednesday, October 22 (DOY 296):

After two hours of magnetospheric studies led by the Cassini Plasma Spectrometer (CAPS), the Navigation team obtained optical navigation images as part of an ongoing activity to track Cassini with as much accuracy as possible as it orbits Saturn. Following a 9-hour downlink to Earth, Imaging Science (ISS) took another set of images in a campaign to track the small satellites orbiting Saturn. This activity was followed by a spacecraft roll designed to assist the Magnetometer Subsystem (MAG) team calibrate the instrument’s sensors.

An encounter strategy meeting was held today to cover the period between Nov. 3 and Nov. 19, Titan flybys T46 and T47, and maneuvers 170, 171 and 172. With a tabletop walk-through today, Spacecraft Operations (SCO) personnel began planning for a re-pressurization of the fuel side of the bipropellant subsystem to maximize the delta-V available for the mission. The procedure will be performed in January, 2009, and is the last planned re-pressurization for the Cassini spacecraft.

Thursday, October 23 (DOY 297):

All teams and instruments delivered files today for Port 1 of the S49 Science Operations Plan process.

The Attitude and Articulation Control Subsystem (AACS) team kicked off the AACS A8.7.7 flight software (FSW) update effort with a working group meeting today. Parameter changes are planned to update the default safing attitudes to support the time frame from June 2009 to July 2010, and to modify the default thruster magnitudes. Uplink is planned in the late May/early June 2009 time-frame.

Friday, October 24 (DOY 298):

Non-targeted flybys of Janus, Pan, and Mimas occurred today.

The Magnetospheric and Plasma Science teams began science activities today with observations of the auroral magnetosphere and Saturn Kilometric Radiation source regions. This was followed by occultation experiments with the Ultraviolet Imaging Spectrograph leading a campaign to track the passage of a star behind the main rings to probe the optical depth, and the suite of Optical Remote Sensing instruments observing the Sun as it passed behind the rings. After the occultations, ISS imaged Mimas to study the geology of that moon, and then performed an azimuthal scan of the rings designed to study the Columbo ringlet. The Composite Infrared Spectrometer wrapped up the day by also performing ring studies.

Cycle #49 of the main engine (ME) cover concluded today after it was stowed in preparation for Orbit Trim Maneuver (OTM) #169 to occur on Oct. 29.

Monday, October 27 (DOY 301):

An image of the south pole of Saturn was Astronomy Picture of the Day today. Check it out at http://antwrp.gsfc.nasa.gov/apod/ap081027.html

As a start to sequence implementation, the final integrated sequence segments for S50, which includes orbits 110 – 112, are due from the Target Working Teams today. Science Operations Plan implementation then begins. A Science Planning Attitude Strategy Spreadsheet will be delivered to the instrument teams on Oct. 29 so that they can begin working on spacecraft pointing designs for this sequence.

Tuesday, October 28 (DOY 302):

CAPS oriented the spacecraft to optimize the acquisition of magnetospheric data for the first two hours of the day. This was followed by ISS searches for new small satellites and observations to track known small satellites.

SCO and Uplink Operations uplinked the following to the spacecraft today: OTM-169, a reaction wheel bias to execute over the OTM-169 backup pass on Oct. 30, the Enceladus 6 live update that will execute Oct. 31, and a Cosmic Dust Analyzer mini-sequence for the E6 flyby, also on Oct. 31.

The Cassini Scientist for a Day essay contest for U.S. students in grades 5-12 has received a record number of entries. The entry deadline is noon PDT on Oct. 30. Already 198 essays by 322 students from 21 classrooms in 18 states have been received. The majority of entries are usually submitted within the last 48 hours before the contest deadline, so Outreach anticipates receiving many more entries over the next two days.

Visit the JPL Cassini home page for more information about the Cassini Project: http://saturn.jpl.nasa.gov/