From: Jet Propulsion Laboratory
Posted: Friday, January 24, 2014
Cassini is orbiting Saturn with a 31.9-day period in a plane inclined 50.1 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on Jan. 22 using one of the 70-meter diameter Deep Space Network stations at Madrid, Spain. 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 and speed of the Cassini spacecraft may be found on the "Present Position" page at:
The on-board S82 command sequence controlled most of the spacecraft's activities this week. One exception was a special command to help celebrate the Deep Space Network's 50th anniversary. Meanwhile, Cassini's Navigation team worked on upcoming Orbit Trim Maneuver opportunities, and the Sequence Implementation Process teams continued working on the ten-week command sequences S83 and S84. Tasks and meetings are on schedule for S85 development. Planning also proceeded for the 2016 start of the F-ring and Proximal Orbits phase.
Wednesday, Jan. 15 (DOY 015)
The Imaging Science Subsystem (ISS) began a 37-hour observation of the irregular moon Tarqeq. Not to be confused with a similar rock that Cassini studies named Tarvos, this moon is about six kilometers in diameter and occupies an inclined orbit about 18 million kilometers from Saturn. Both are named after Inuit gods.
Thursday, Jan. 16 (DOY 016)
The Spacecraft team developed a special command file that executed today. It caused Cassini to read out some memory into the telemetry stream which, when received and decoded, became a message congratulating the Deep Space Network (DSN) on its 50th anniversary. In a news feature, one of the DSN's 70-meter diameter antennas can be seen "reading" its clever "birthday card":
If you enlarge the image, you'll see the actual message that Cassini sent; its binary ones and zeros appear in hexadecimal (base-16) notation that can be translated into English-language text using a converter that can easily be found online.
Friday, Jan. 17 (DOY 017)
The Cosmic Dust Analyzer (CDA) began a 33-hour observation of dust that orbits Saturn in the retrograde direction.
Saturday, Jan. 18 (DOY 018)
The DSN used its 70-meter diameter station in Australia today to track Cassini for nine hours. This session was one of four DSN passes this week for Cassini, using stations in Spain as well as in Australia.
Sunday, Jan. 19 (DOY 019)
CDA performed another retrograde dust observation, this one about 24 hours long. Roughly halfway through it, the spacecraft drifted past apoapsis, marking the start of Saturn Orbit #201. The spacecraft had slowed to 9,990 kilometers per hour relative to the planet, and will spend the next sixteen days falling and speeding back towards periapsis.
Monday, Jan. 20 (DOY 020)
ISS started taking 28 hours worth of images to make a movie of the dark-face ring spokes (http://go.usa.gov/4WGP) at high phase-angle illumination, to search for spoke periodicities.
In an image featured today, Saturn's rings are lit by sunlight from directly behind the spacecraft. The bright "opposition surge" spot identifies the location of zero-phase illumination. Views such as this one help reveal the ring particles' nature. ISS took the image using an infrared filter that passes a particular polarization of light:
Tuesday, Jan. 21 (DOY 021)
After ISS completed its spoke movie, VIMS made a two-minute storm-watch observation on Saturn.
Visit the JPL Cassini home page for more information about the Cassini Project: http://saturn.jpl.nasa.gov/
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