ron
July 27th 09, 06:02 AM
Cassini Significant Events
for 07/15/09 - 07/21/09
The most recent spacecraft telemetry was acquired on July 21 from the
Deep
Space Network tracking complex at Madrid, Spain. 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, July 15 (DOY 196)
An encounter strategy meeting was held today to cover the period
between
July 24 and August 9, Titan flybys T59 and T60, and maneuvers 109-111.
The Target Working Team (TWT)/ Orbiter Science Team (OST) integrated
products for S57, covering orbits 125 through 127, from January 2010
through
March 2010, were delivered today. The integrated products are in their
final
form and no re-integration is planned. The next step in sequence
development, Science Operations Plan (SOP) implementation, will kick
off on
July 29. Between now and then, the instrument teams will be working on
pointing designs for the sequence. TWT/OST teams deliver integrated
sequence
products for the extended mission about every five weeks.
Thursday, July 16 (DOY 197):
Science today included Imaging Science (ISS) observations of the
retinue of
small moons following Saturn, and the Magnetospheric and Plasma
Science
(MAPS) instruments' study of the solar wind boundary of Saturn's
magnetosphere. This was followed by a Composite Infrared Spectrometer
(CIRS)
observation designed to study the polarization of light reflected from
Saturn's rings at far infrared wavelengths.
Today sequence leads uplinked seven Instrument Expanded Block (IEB)
files to
the spacecraft in support of S52. The remaining two IEBs will go up
on
Saturday, and the background sequence will go up on Monday. The S52
sequence will begin execution on Thursday, July 23.
Friday, July 17 (DOY 198):
Today the Visual and Infrared Mapping Spectrometer (VIMS) trained its
sensors on Antares for calibration purposes. Periodic calibration is
critical to the successful interpretation of VIMS and other instrument
observations. The calibration was followed by another MAPS study of
the
boundary region of the magnetosphere, and Navigation imaging. At the
end of
the day the Ultraviolet Imaging Spectrograph (UVIS) turned towards
Sagittarius to watch it slip behind the rings of Saturn.
Orbit Trim Maneuver (OTM) #207 was performed today. This was the
apoapsis
maneuver setting up for the Titan 59 encounter on July 23. The
Reaction
Control Subsystem (RCS) burn began at 10:15 AM PDT. Telemetry
immediately
after the maneuver showed the burn duration was 24.13 seconds, giving
a
delta-V of 32.68 mm/s. All subsystems reported nominal performance
after the
maneuver.
Saturday, July 18 (DOY 199):
A nearly edge-on telescopic view of Saturn's rings was offered to 100
attendees at a star party in Warner Springs, CA, on July 18. Cassini
Outreach members participated in the event.
Monday, July 20 (DOY 201):
After the kick off meeting today for the DOY 207 Live Inertial Vector
Propagator (IVP) update, instrument teams reviewed the impact if the
update
were cancelled. It turned out that CIRS would have lost part of their
observation and ISS would not have gotten their images of the plumes
along
the limb of Enceladus. As a result, the team will proceed with the
update
and vectors for both Saturn and Janus for ISS and VIMS will be
updated.
Final files will be delivered on July 23 with an approval meeting held
on
July 24. The files will be uplinked that same day and will execute on
Sunday, July 26.
Tuesday, July 21 (DOY 202):
Thanks to accurate orbit determination and execution of OTMs 206 and
207,
the maneuver planned to correct the delivery dispersions for the Titan
59
flyby was smaller than the permissible minimum RCS maneuver magnitude.
Execution of OTM-208 would have required the addition of a time of
closest
approach bias to increase the magnitude to an achievable level.
Science
planning has evaluated both the maneuver and no-maneuver cases and
found
both to be acceptable. Cancellation reduced the predicted down stream
delta-V by about 90 mm/sec. Therefore OTM 208, originally scheduled to
execute today, was cancelled.
Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>
for 07/15/09 - 07/21/09
The most recent spacecraft telemetry was acquired on July 21 from the
Deep
Space Network tracking complex at Madrid, Spain. 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, July 15 (DOY 196)
An encounter strategy meeting was held today to cover the period
between
July 24 and August 9, Titan flybys T59 and T60, and maneuvers 109-111.
The Target Working Team (TWT)/ Orbiter Science Team (OST) integrated
products for S57, covering orbits 125 through 127, from January 2010
through
March 2010, were delivered today. The integrated products are in their
final
form and no re-integration is planned. The next step in sequence
development, Science Operations Plan (SOP) implementation, will kick
off on
July 29. Between now and then, the instrument teams will be working on
pointing designs for the sequence. TWT/OST teams deliver integrated
sequence
products for the extended mission about every five weeks.
Thursday, July 16 (DOY 197):
Science today included Imaging Science (ISS) observations of the
retinue of
small moons following Saturn, and the Magnetospheric and Plasma
Science
(MAPS) instruments' study of the solar wind boundary of Saturn's
magnetosphere. This was followed by a Composite Infrared Spectrometer
(CIRS)
observation designed to study the polarization of light reflected from
Saturn's rings at far infrared wavelengths.
Today sequence leads uplinked seven Instrument Expanded Block (IEB)
files to
the spacecraft in support of S52. The remaining two IEBs will go up
on
Saturday, and the background sequence will go up on Monday. The S52
sequence will begin execution on Thursday, July 23.
Friday, July 17 (DOY 198):
Today the Visual and Infrared Mapping Spectrometer (VIMS) trained its
sensors on Antares for calibration purposes. Periodic calibration is
critical to the successful interpretation of VIMS and other instrument
observations. The calibration was followed by another MAPS study of
the
boundary region of the magnetosphere, and Navigation imaging. At the
end of
the day the Ultraviolet Imaging Spectrograph (UVIS) turned towards
Sagittarius to watch it slip behind the rings of Saturn.
Orbit Trim Maneuver (OTM) #207 was performed today. This was the
apoapsis
maneuver setting up for the Titan 59 encounter on July 23. The
Reaction
Control Subsystem (RCS) burn began at 10:15 AM PDT. Telemetry
immediately
after the maneuver showed the burn duration was 24.13 seconds, giving
a
delta-V of 32.68 mm/s. All subsystems reported nominal performance
after the
maneuver.
Saturday, July 18 (DOY 199):
A nearly edge-on telescopic view of Saturn's rings was offered to 100
attendees at a star party in Warner Springs, CA, on July 18. Cassini
Outreach members participated in the event.
Monday, July 20 (DOY 201):
After the kick off meeting today for the DOY 207 Live Inertial Vector
Propagator (IVP) update, instrument teams reviewed the impact if the
update
were cancelled. It turned out that CIRS would have lost part of their
observation and ISS would not have gotten their images of the plumes
along
the limb of Enceladus. As a result, the team will proceed with the
update
and vectors for both Saturn and Janus for ISS and VIMS will be
updated.
Final files will be delivered on July 23 with an approval meeting held
on
July 24. The files will be uplinked that same day and will execute on
Sunday, July 26.
Tuesday, July 21 (DOY 202):
Thanks to accurate orbit determination and execution of OTMs 206 and
207,
the maneuver planned to correct the delivery dispersions for the Titan
59
flyby was smaller than the permissible minimum RCS maneuver magnitude.
Execution of OTM-208 would have required the addition of a time of
closest
approach bias to increase the magnitude to an achievable level.
Science
planning has evaluated both the maneuver and no-maneuver cases and
found
both to be acceptable. Cancellation reduced the predicted down stream
delta-V by about 90 mm/sec. Therefore OTM 208, originally scheduled to
execute today, was cancelled.
Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>