NASA Cassini Significant Events 01/18/07 – 01/24/07
The most recent spacecraft telemetry was acquired on Wednesday, Jan. 25, from the Goldstone tracking complex. 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” web page at http://saturn.jpl.nasa.gov/operations/present-position.cfm
Thursday, Jan. 18 (DOY 018):
A tabletop walk though of the AACS Flight Computer Reset Recovery procedure was held today. This is another in a series of reviews to familiarize the spacecraft team with Fault Protection responses.
Today eight members of the Cassini Science Planning and Outreach Teams toured the Goldstone Deep Space Communications Complex. They observed operations, met with members of the Goldstone technical staff, and spent the day learning how the facility operates.
Most of today’s science activity focused on Saturn’s rings. The Visible and Infrared Mapping Spectrometer (VIMS) made a mosaic on each ansa for latitude and phase coverage with the Imaging Science Subsystem (ISS) and Composite Infrared Spectrometer (CIRS) riding along. CIRS made a radial scan of the main rings at afternoon to obtain thermal measurements of the rings. At the same time the Ultraviolet Imaging Spectrograph (UVIS) made an ultraviolet spectral mapping of the rings. Additional activities included RADAR obtaining radiometer data of northern latitudes on Titan.
The spectacular view of Saturn, In Saturn’s Shadow, proved to be the most popular in the Cassini Photo Contest II. To view the results of the contest link to: http://saturn.jpl.nasa.gov/multimedia/poll/index.cfm
Friday, Jan. 19 (DOY 019):
On Friday, Outreach participated in a space science day at Palos Verdes Intermediate School in Palos Verdes Estates, California. Three hundred fifty eighth grade students attended the presentations, which included demonstrations on spacecraft communications, Mars rovers, and Cassini science highlights. The event was written up in the local Palos Verdes newspaper.
Images of satellites Atlas and Pan were taken by ISS today. Additional images of Mimas and Tethys were obtained for optical navigation. Rings studies included a CIRS radial scan of the main rings to measure temperature, a UVIS ultraviolet spectral map, and a wide-angle camera mosaic of the entire ring system in multiple colors providing ring system photometry.
An article on the jet stream of Titan by the European Space Agency has been reproduced on the Cassini web site. For details on how a pair of rare celestial alignments occurring in November 2003 provided on going science results in 2007, link to: http://saturn.jpl.nasa.gov/news/features/feature20070124.cfm
Saturday, Jan. 20 (DOY 020):
The Magnetospheric and Plasma Science (MAPS) instruments are continuing their magnetospheric survey this week.
On Saturday, an occultation of the close binary bright star Epsilon Lup by the outer B ring was observed in the far ultraviolet by UVIS. The grazing path of this occultation made a “u-turn” in the middle of the B ring.
Sunday, Jan. 21 (DOY 021):
Orbit Trim Maneuver (OTM) #90 was performed today. This is the apoapsis maneuver setting up for the Titan 24 encounter on Jan. 29. The main engine burn began at 2:45 AM PST. Telemetry immediately after the maneuver showed the burn duration was 14.7 seconds, giving a delta-V of 2.37 m/s. All subsystems reported nominal performance after the maneuver.
Monday, Jan. 22 (DOY 022):
Observations today included UVIS observing the occultation of the star Gamma Ara by the rings. The high resolution radial profile of ring optical depth derived from the fluctuation of starlight passing through the rings at multiple azimuths and from multiple distances provides detailed information on ring structure and dynamics, ring-moon interactions, and ring particle sizes. The egress path cut through all rings on the north face in the planet shadow.
ISS took a mini-movie of the unlit face of the rings to observe azimuthally variable structure. At an elevation angle of 59 degrees, this is the highest such observation. Optical navigation images were taken of Tethys, Enceladus, and Rhea.
Tuesday, Jan. 23 (DOY 023):
Activities on board the spacecraft today included Ion and Neutral Mass Spectrometer (INMS) instrument flight software normalization, and an annual Stellar Reference Unit calibration.
At the Mission Planning (MP) Forum this week, MP gave a presentation on activities leading up to the Project Science Group (PSG) meeting to be held at JPL next week. The presentation included the ten tours currently under review by the science teams, team/Orbiter Science Team/Target Working Team activities, and the system to use to rate each of the tours. It is expected that the extended mission tour will be selected by the end of the week-long PSG meeting.
Cassini Outreach provided telescopic views of Saturn to about 200 people today at the Glendale, CA, public library. The viewers also were able to see Titan, and compare it to Earth’s smaller but nearer moon, which was visible through other nearby telescopes.
UVIS continued its Satellite/System Volatile Map, imaging the local environment around Enceladus to characterize the origin of volatiles. At Enceladus, any connection of volatile changes to plume eruptions is of particular interest.
Wednesday, Jan. 24 (DOY 024):
This week the Navigation team presented an overview of Optical Navigation as part of ongoing OTM related training within the Spacecraft Operations Office.
The MAPS outer magnetosphere survey was interrupted today to allow two instruments to perform calibrations. At a quiescent spot in Saturn’s magnetic field, the spacecraft rolled to allow the Magnetometer to determine sensor offsets, and the Radio and Plasma Wave Science instrument performed periodic instrument maintenance for the Langmuir Probe.
Upcoming:
Cassini Outreach, Saturn Observation Campaign (SOC) members and the Sidewalk Astronomers will be showing views of Saturn and the moon at these public events:
Jan. 26, 6-9 p.m. Colorado Blvd in Old Town Pasadena, CA Jan. 27, 5-9 p.m. Library Park, Myrtle and Lime Streets in Monrovia, CA. For more information, contact Cassini Outreach. You can also contact any SOC member in more than 50 countries for local events: http://soc.jpl.nasa.gov/members.cfm
During Cassini’s next pass of Saturn’s moon Titan on Jan. 29, its infrared eyes will study the moon’s murky atmosphere and peer through its thick, smoggy veil, mapping surface features. http://saturn.jpl.nasa.gov/news/events/titan20070129/index.cfm
The Saturn Tour Highlights have been updated with events to come throughout 2007. To see what is on the Cassini horizon, link to http://saturn.jpl.nasa.gov/operations/index.cfm.
