Cassini Significant Events 09/26/2012 – 10/02/2012

The most recent spacecraft tracking and telemetry data were collected on Oct. 2 by the Deep Space Network's 70 meter Station 63 at Madrid, Spain. Except for the Cassini Plasma Spectrometer, which is off, and the failed Ultrastable Oscillator, the Cassini spacecraft continues to be in an excellent state of health with all its subsystems functioning normally. Information on the present position of the Cassini spacecraft may be found on the "Present Position" page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

Cassini obtained in-situ and remote-sensing measurements, including radar imaging, during the T-86 flyby of Titan on Wednesday. The spacecraft also obtained a gravity assist designed to increase its orbital inclination from 32.2 to 39.0 degrees relative to Saturn's equatorial plane, while increasing the period by a few days to a 23.9-day orbit.

Wednesday, Sept. 26 (DOY 270)

While Cassini was inbound to Titan, the Composite Infrared Spectrometer (CIRS) mapped temperatures and gas abundances, and the Ultraviolet Imaging Spectrograph (UVIS) observed Titan's atmosphere at extreme- and far-ultraviolet wavelengths. The Imaging Science Subsystem (ISS) rode along (piggybacked on the other instruments' pointing) with the CIRS and UVIS observations, acquiring data to image Titan's surface and atmosphere. The Visible and Infrared Mapping Spectrometer (VIMS) rode along to look for specular reflections of sunlight on the northern lakes. RADAR actively acquired its Synthetic Aperture Radar (SAR) data, and then outbound from Titan it took altimetry measurements.

For the two hours around closest approach, attitude control was commanded to switch from reaction wheels to Reaction Control Subsystem (RCS) thrusters for increased control authority over atmosphere-generated torques.

The Magnetometer (MAG) was able to observe the post-noon sector of Saturn's magnetosphere, and studied the diffusion of the external magnetic field at low altitudes and low solar zenith angles. The Radio and Plasma Wave Science instrument (RPWS) measured thermal plasmas in Titan's ionosphere and surrounding environment, searched for lightning, and investigated Titan's interaction with Saturn's magnetosphere. Additional discussion about the T-86 flyby appears here: http://saturn.jpl.nasa.gov/mission/flybys/titan20120926/

Meanwhile on Earth, the Deep Space Network (DSN) was performing its periodic "Global Downtime" maintenance and engineering activities. Many of the Cassini ground system computers and local networks took advantage of the scheduled pause in data flow to perform minor upgrades and resets.

Thursday, Sept. 27 (DOY 271)

CIRS observations continued outbound from Titan, then Cassini turned to Earth. The T-86 playback telemetry data traveled 1.595 billion kilometers and encountered heavy rain within the last few hundred meters, causing a few percent of the data to be lost.

Friday, Sept. 28 (DOY 272)

ISS monitored Titan for an extra day to track clouds. VIMS rode along to monitor post-equinox climate changes.

Saturday, Sept. 29 (DOY 273)

CIRS performed an 8-hour stray light calibration by monitoring scattered infrared solar radiation as a function of offset angle from the sun using radial scans. The Cosmic Dust Analyzer (CDA) performed a 6.5-hour observation of particles moving in a retrograde direction.

Orbit Trim Maneuver (OTM) 332, the Titan T-86 post-flyby trajectory cleanup maneuver, was performed today using the RCS thrusters. The 179-second burn provided a delta-V of about 189 millimeters per second.

Sunday, Sept. 30 (DOY 274)

This week, a feature was posted to solicit readers' votes on their favorite of Cassini's "Shining Moments." It may be accessed here: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20120926/.

Monday, Oct. 1 (DOY 275)

ISS observed the 7-kilometer diameter irregular moon Bestla (also known as Bestia) for 5 hours at a distance of about 20 million kilometers. ISS performed another observation in the Satellite Orbit Campaign looking near Saturn, to improve knowledge of small satellites' orbits or make new discoveries. ISS then began to capture a 16-hour movie of the Encke Gap in the outer A ring, an observation which is performed twice per year.

An image of a ray crater on the leading hemisphere of Saturn's moon Dione was featured today. "Dione Ray Crater" may be seen here: /resources/15642

Tuesday, Oct. 2 (DOY 276)

After the Encke Gap movie, ISS, CIRS and VIMS performed another observation in the Titan monitoring campaign from a distance of 2.9 million kilometers. CIRS then began a 24-hour mid-infrared map of Saturn to determine upper troposphere and tropopause temperatures.