Cassini Significant Events
06/11/08 - 06/17/08
The most recent spacecraft telemetry was acquired on Tuesday, June
17, from the Goldstone, California, 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" page
at: http://saturn.jpl.nasa.gov/operations/present-position.cfm.
Wednesday, June 11 (DOY 163)
Science activities today included the Ultraviolet Imaging
Spectrograph (UVIS) performing calibration activities and a stellar
ring occultation, and the Visual and Infrared Mapping Spectrometer
(VIMS) obtaining images for a ring plane crossing movie.
Spacecraft Operations sent commands to the spacecraft to update the
Reaction Control Subsystem (RCS) B branch thrust magnitude. This
activity is performed periodically to keep the on-board thrust values
in the flight software consistent with the actual physical values as
the pressure decays in the hydrazine tank.
Thursday, June 12 (DOY 164)
The Navigation team has scheduled three critical Optical Navigation
(OPNAV) events for August to support the Enceladus 4 flyby on Aug.
11. In this case, 'critical' means to provide extra support for the
data processing and be prepared to intervene manually in case there
is a problem with the data processing. Standard procedure is to wait
until the end of pass to try a replay of the data if anything is
missed. To support this request, members of the Multi-mission Image
Processing Laboratory are reviewing and practicing procedures to
ensure on-time delivery of image data to Navigation.
Friday, June 13 (DOY 165):
A non-targeted flyby of Titan occurred today.
Uplink Operations was busy this week sending commands to the
spacecraft. Yesterday part 2 of the S41 background sequence was
radiated. Sequence leads have verified that the file has been
properly received and registered onboard. Execution will begin on
Wed., June 18.
Commands were sent for Radio and Plasma Wave Science (RPWS) to modify
direction finding in survey mode by changing from antenna 2 to
antenna 3. Files for the DOY 168 S41 RSS Saturn Occultation Ingress
Live Movable Block and the S41 Live Inertial Vector Propagator Update
for Saturn, Mimas, and Dione were sent on DOY 167. The updated files
will begin execution early Sunday morning.
On Sunday, VIMS will record movies on Saturn atmospheric dynamics and
observe two stellar-ring occultations. The suite of Magnetospheric
and Plasma Science (MAPS) instruments will observe the auroral
crossing, and the Composite Infrared Spectrometer (CIRS) will perform
radial scans of the rings and perform a nadir occultation
observation. This observation will look to obtain spectra in the
vicinity of previous Radio Science occultation points to obtain a new
helium determination.
Monday, June 16 (DOY 168):
Non-targeted flybys of Epimetheus, Prometheus, and Methone occurred today.
Science Planning hosted the kick-off meeting for the S46 Science
Operations Plan process today. The process will last about 14 weeks
with final products being handed over to the Sequence leads for the
final development process in September. S46 begins execution
on-board the spacecraft on Nov. 26.
The Cassini Radio Science (RSS) orbit 72 Saturn atmospheric
occultation observation was completed in the early hours of the
morning today. The purpose of the activity was to observe the
ingress to Saturn's ionosphere and atmosphere to measure vertical
profiles of electron density in the ionosphere, and density,
pressure, and temperature in the neutral atmosphere. Antennas at the
Goldstone, Canberra and Narrabri complexes supported the experiment.
Goldstone's DSS-14, 25 and 26 and Narrabri's DSS-47 provided partial
support, while Canberra's DSS-43 and DSS-34 covered the entire
experiment. This was the first time ever that four antennas tracked
Ka-band simultaneously: DSS-25, 26, 34 and 47. Previously, three was
the most to support this type of activity. RSS has one more science
observation in the Cassini prime mission, the orbit 73 atmospheric
occultation on DOY 175 (June 23) over Canberra and Narrabri.
The kick-off meeting for the fourth S41 Live Update, this time for
DOY 173, occurred today. Based on the analysis and concurrence from
Science Planning, Imaging Science, CIRS, and VIMS, the team will
update the Saturn and Tethys vectors. The live movable block for RSS
on DOY 175 will also updated.
Tuesday, June 17 (DOY 169):
Two members of the Spacecraft Operations Office (SCO) will be
staffing the NASA exhibit at the Smithsonian Folk Life Festival in
Washington, DC, the last week of June and first week of July.
SCO hosted an S47 Engineering Activities Review today to discuss all
the spacecraft activities that will be performed during that sequence.
To wrap up the week, CIRS led a joint Optical Remote Sensing
observation of a Rhea solar eclipse exit and performed radial ring
scans, and VIMS collected data for Saturn movies.
-------------------------------------------
To unsubscribe from Cassini Spacecraft Updates, send a message to
leave-cassini@xxxxxxxxxxxxxxxxx
from the email address you wish to unsubscribe. You will receive a
confirmation message to which you must respond in order to
unsubscribe.
-------------------------------------------
Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>
