Cassini is orbiting Saturn with a 31.9-day period in a plane inclined 44.3 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on June 4 using one of the 34-meter diameter Deep Space Network (DSN) station at Goldstone, California. Except for the science instrument issues described in previous reports (for more information search the Cassini website for "CAPS" and "USO"), the spacecraft continues to be in an excellent state of health with all of its subsystems operating normally. Information on the present position of the Cassini spacecraft may be found on "Eyes on the Solar System."
The 10-week command sequence S84 controlled all the spacecraft's activities this week. Meanwhile on the ground, Cassini's Sequence Implementation Process teams worked on the 10-week sequences S85 and S86, and prepared for S87. Planning continued for the 2016 start of the F-ring and Proximal Orbits mission phase.
Wednesday, May 28 (DOY 148)
Cassini continued its study of Saturn's northern auroral region in a campaign that the science teams have assigned a high priority for this part of the mission. The Ultraviolet Imaging Spectrograph (UVIS) was the prime instrument, directing spacecraft pointing for a mixture of slews across the auroral oval and fixed stares at it. The Magnetospheric Imaging Instrument (MIMI) and the Visible and Infrared Mapping Spectrometer (VIMS) also participated. These observations, six of them this week, lasted between 12 hours and 37.25 hours each. Results from some similar observations from last year may be seen in a video here: http://saturn.jpl.nasa.gov/video/videodetails/?videoID=272
Friday, May 29 (DOY 150)
The first and lengthiest of this week's UVIS-led Saturn auroral observations completed with a turn back to Earth and a data playback. The Imaging Science Subsystem (ISS) then took control of the spacecraft to point its telescopes to Titan for 1.5 hours as part of the ongoing Titan monitoring campaign. VIMS and the Composite Infrared Spectrometer (CIRS) took advantage of the pointing and participated as well. This relatively short observation repeated on Saturday, Sunday, Monday, and again on Tuesday.
Saturday, May 30 (DOY 151)
During one of the UVIS-led auroral observations today, the spacecraft coasted through apoapsis at a point just over three million kilometers "above" Saturn. This marked the start of Cassini's orbit #205.
Sunday, June 1 (DOY 152)
The DSN carried out six nine-hour sessions linking with Cassini this week, using the 70-meter diameter station and the 34-meter stations at Goldstone, California. The round-trip light time was just over two hours 28 minutes today, and it is increasing by a few seconds each day.
To date, the Cassini Program has acquired, transmitted, processed, and published more than 318,000 ISS images and over 210,000 VIMS cubes.
Monday, June 2 (DOY 153)
A view of Saturn's largest moon Titan was featured today. With the sunlight illuminating its thick atmosphere in crescent phase, high clouds that form in a vortex above the south pole can be seen towering above the rest of the haze: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=5033
Tuesday, June 3 (DOY 154)
The S84 command sequence was designed with a gap in it so that the flight team would be able to command an Orbit Trim Maneuver (OTM) today. This one, OTM-381, would have taken advantage of the orbital-mechanics "leverage" available near apoapsis to adjust the spacecraft's flight path for the Titan T-102 encounter coming up on June 18. But the Cassini Navigation Team's analysis showed that the OTM would not be necessary, and it was cancelled. There will be an opportunity three days before T-102 for OTM-382, which will be designed near real time, uplinked, and executed to fine-tune for a passage 3,658.6 kilometers above the surface of the 5,152-kilometer diameter moon.
Saturn is rising in the east just after sunset these days, and it remains a fine target for viewing in any sort of telescope. Dark skies are not necessary; streetlights don't even matter much. Look for the ringed gas giant (with at least Titan easily visible) above the Earth's Moon in the sky on June 10 and 11.