Cassini Significant Events
for 11/18/09 - 11/23/09
The most recent spacecraft telemetry was acquired on Nov. 23 from the
Deep Space Network tracking complex at Canberra, Australia. 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, Nov. 18 (DOY 322)
A news note called "Before Darkness Falls: Cassini to Scan Enceladus
on Winter's Cusp" previewed the upcoming Enceladus flyby, describing
it as "a last peek at the intriguing 'tiger stripes' before winter
darkness blankets the area for several years." Scientists are
particularly interested in the tiger stripes, which are fissures in
the south polar region, because they spew jets of water vapor and
other particles hundreds of kilometers from the surface.
http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20091119/
A web feature story, "Cassini's Big Sky: The View from the Center of
Our Solar System," described how Cassini recently helped rewrite our
understanding of the shape of our solar system. For decades,
scientists pictured our solar system as having a comet-like
appearance. The new results suggest a picture more like a bubble.
http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20091120/
The main engine cover was closed on Nov. 18 at the end of the Orbit
Trim Maneuver (OTM) #223 backup pass.
Port 2 files were due today as part of the S59 Science Operations
Plan process. The files have been merged and a Science Planning
assessment of the product released for review.
Both the Live update and Live Update block for the Enceladus 8 flyby
were sent up to the spacecraft today along with a tweak to the
Magnetometer Subsystem (MAG) Flux Gate Magnetometer (FGM) autorange
boundaries.
Thursday, Nov. 19 (DOY 323):
In addition to the Enceladus 8 flyby, science this week included
Visual and Infrared Mapping Spectrometer (VIMS) leading a joint
Optical Remote Sensing (ORS) E and G ring phase observation and a
joint ORS mosaic of Saturn to look at global dynamics. VIMS spent
some time looking at Saturn's northern hemisphere dynamics, and the
Composite Infrared Spectrometer (CIRS) performed a helium abundance
measurement at the Radio Science (RSS) occultation egress point.
Imaging Science (ISS) acquired data for more Saturn wide-angle camera
photopolarimetry and lightning searches, and observed the transit of
Pandora across Epimetheus for orbit determination purposes.
The Magnetospheric and Plasma Science (MAPS) teams continued the
magnetospheric boundaries campaign and began a campaign to examine
interactions between the rings and the satellites.
The Ultraviolet Imaging Spectrograph (UVIS) observed Dione, measuring
the satellite's albedo in ultraviolet light to determine the phase
function.
This is part of the ongoing campaign to investigate surface
microstructure and frost properties as a function of location. CIRS
and VIMS rode along.
Friday, Nov. 20 (DOY 324):
A non-targeted flyby of Helene occurred today, and tomorrow along
with the Enceladus 8 targeted flyby will be non-targeted flybys of
Pandora, Titan, Calypso and Rhea.
On DOY 324 Cassini Radio Science (RSS) successfully completed the
orbit 121 Saturn occultation experiment. The experiment was an egress
only atmospheric occultation and was covered by Canberra's DSS-43 for
X- and S-band, and DSS-34 for X- and Ka-band. It is the second of a
sequence of three occultations in the Cassini Equinox Mission that
probe Saturn's mid-northern latitude, a region which was sparsely
sampled during the prime mission. The latitude probed on Rev 121 was
about 27.5 deg north as measured near the top of the troposphere.
Measurements of the S-, X-, and Ka-band signals' amplitude,
frequency, and phase provide information about the large- and
small-scale structure of the atmosphere, the temperature and pressure
profile, zonal wind, abundance of microwave absorbing species, the
electron number density profile of the ionosphere, and on variability
of the profiles with latitude and solar zenith angle.
Saturday, Nov. 21 (DOY 325):
The main engine cover was opened today. This was the 53rd in-flight
cycle. The stow position reached a nominal 33.04 degrees.
Just under three weeks after the Enceladus 7 flyby, Cassini once
again flew past Enceladus, this time with a very different geometry,
approaching within 1,600 kilometers of the surface. E8 closest
approach occurred at 2009-325T05:15:03 SCET, at a speed of 7.7 km/sec
at 82 degrees S latitude. The spacecraft was under thruster control
during the flyby to allow for precise tracking of surface features.
VIMS observed Enceladus as the moon emerged from eclipse, followed by
a CIRS fast raster scan of Enceladus' night side. ISS then took over
for high-resolution plume observations obtaining a clear filter
mosaic of terrain on the leading hemisphere, providing the
best-resolution mosaic so far of that hemisphere. This data can be
combined with earlier images of the same region at different
geometries to create high-resolution topographic maps, and will be
used to look for possible temporal variations in the morphology of
the tiger stripes.
CIRS had prime pointing control during closest approach for a high
resolution FP3 scan of Baghdad Sulcus - one of the tiger stripe
features - tracking along the fissure in the south polar region to
examine plume sources and producing the highest-ever-resolution
contiguous thermal map of this region.
ISS and VIMS then mapped the sunlit surface of Enceladus on
departure. UVIS performed a long stare for a tenuous atmosphere
search, which will provide
data to associate plume activity with the quantity of volatiles near
Enceladus. Over the following downlink of data, RSS performed gravity
science to better determine Enceladus' mass.
Shortly after the targeted Enceladus flyby, Cassini flew less than
25,000 kilometers from Rhea, allowing for ISS high-resolution imaging
- around 150-175 m/px - and compositional mapping of regions
including the fractured "wispy terrain," followed by a VIMS
point-and-stare observation. UVIS searched for the Rhea ring,
targeting beta Ori and kappa Ori. This observation was also used to
look for volatiles. Finally, CIRS performed a limb-to-limb fast scan
along Rhea's equator, including night and early morning local times.
To view the flyby page for this encounter link to:
http://saturn.jpl.nasa.gov/mission/flybys/enceladus20091121/
Following the flyby this unprocessed image was posted to the Cassini
webpage. It shows the ridges and fractures on the surface of the icy
moon.
Link to: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=3749
In a news note called "Cassini Sends Back Images of Enceladus as
Winter Nears," mission managers said the spacecraft sailed seamlessly
through its Enceladus flyby. The spacecraft has sent back temperature
data and spectacular images, including ones of the jets of water
vapor and other particles emanating from the moon's south polar
region. For the full text and links to additional information go to:
http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20091121/
Sunday, Nov. 22 (DOY 326):
On Nov. 21, after the E8 flyby, a solid-state power switch (SSPS)
trip occurred that turned VIMS off and turned the replacement heater
turn on. Real time commands were sent today to turn the instrument
and supplemental heater back on and the replacement heater off. This
was the first SSPS trip since Nov. 26, 2008. VIMS is currently in a
safe state and operating normally.
OTM #224 was performed today. This was the cleanup maneuver from the
E8 encounter on Nov 21. The main engine burn began at 2:44 PM PST.
Telemetry immediately after the maneuver showed a burn duration of
14.94 seconds, giving a delta-V of 2.54 m/s. All subsystems reported
nominal performance after the maneuver.
Monday, Nov. 23 (DOY 327):
The Science Operations Plan process for S60 kicked off today. Two new
milestones have been added to this process for prime-rider instrument
coordination. The first delivery port for this sequence is
scheduled for Dec. 15.
Update:
On Tuesday, Nov. 24, images and a movie were released showing the
tallest known "northern lights" in the solar system, flickering in
shape and brightness high above Saturn. Ultraviolet and infrared
instruments on Cassini have captured images of Saturn's auroras
before, but in the latest images, Cassini's camera was able to
capture the northern lights in the visible part of the light
spectrum, in higher resolution. This is the first visible-light video
of the auroras. The release also features an explanatory video.
Visit: http://saturn.jpl.nasa.gov/video/videodetails/?videoID=198
Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>
------------------------
http://www.jpl.nasa.gov/news/news.cfm?release=2009-176
Cassini Captures Ghostly Dance Of Saturn's Northern Lights
Jet Propulsion Laboratory
November 24, 2009
PASADENA, Calif. - In the first video showing the auroras above the
northern latitudes of Saturn, Cassini has spotted the tallest known
"northern lights" in the solar system, flickering in shape and
brightness high above the ringed planet.
The new video reveals changes in Saturn's aurora every few minutes, in
high resolution, with three dimensions. The images show a previously
unseen vertical profile to the auroras, which ripple in the video like
tall curtains. These curtains reach more than 1,200 kilometers (750
miles) above the edge of the planet's northern hemisphere.
The new video and still images are online at:
http://www.nasa.gov/cassini , http://saturn.jpl.nasa.gov and
http://ciclops.org .
Auroras occur on Earth, Jupiter, Saturn and a few other planets, and the
new images will help scientists better understand how they are generated.
"The auroras have put on a dazzling show, shape-shifting rapidly and
exposing curtains that we suspected were there, but hadn't seen on
Saturn before," said Andrew Ingersoll of the California Institute of
Technology in Pasadena, who is a member of the Cassini imaging team that
processed the new video. "Seeing these things on another planet helps us
understand them a little better when we see them on Earth."
Auroras appear mostly in the high latitudes near a planet's magnetic
poles. When charged particles from the magnetosphere -- the magnetic
bubble surrounding a planet -- plunge into the planet's upper
atmosphere, they cause the atmosphere to glow. The curtain shapes show
the paths that these charged particles take as they flow along the lines
of the magnetic field between the magnetosphere and the uppermost part
of the atmosphere.
The height of the curtains on Saturn exposes a key difference between
Saturn's atmosphere and our own, Ingersoll said. While Earth's
atmosphere has a lot of oxygen and nitrogen, Saturn's atmosphere is
composed primarily of hydrogen. Because hydrogen is very light, the
atmosphere and auroras reach far out from Saturn. Earth's auroras tend
to flare only about 100 to 500 kilometers (60 to 300 miles) above the
surface.
The speed of the auroral changes in the video is comparable to some of
those on Earth, but scientists are still working to understand the
processes that produce these rapid changes. The height will also help
them learn how much energy is required to light up auroras.
"I was wowed when I saw these images and the curtain," said Tamas
Gombosi of the University of Michigan in Ann Arbor, who chairs Cassini's
magnetosphere and plasma science working group. "Put this together with
the other data Cassini has collected on the auroras so far, and you
really get a new science."
Ultraviolet and infrared instruments on Cassini have captured images of
and data from Saturn's auroras before, but in these latest images,
Cassini's narrow-angle camera was able to capture the northern lights in
the visible part of the light spectrum, in higher resolution. The movie
was assembled from nearly 500 still pictures spanning 81 hours between
Oct. 5 and Oct. 8, 2009. Each picture had an exposure time of two or
three minutes. The camera shot pictures from the night side of Saturn.
The images were originally obtained in black and white, and the imaging
team highlighted the auroras in false-color orange. The oxygen and
nitrogen in Earth's upper atmosphere contribute to the colorful flashes
of green, red and even purple in our auroras. But scientists are still
working to determine the true color of the auroras at Saturn, whose
atmosphere lacks those chemicals.
The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the Italian Space Agency. The Jet Propulsion
Laboratory, a division of the California Institute of Technology in
Pasadena, manages the mission for the Science Mission Directorate at
NASA Headquarters in Washington. The Cassini orbiter and its two onboard
cameras were designed, developed and assembled at JPL. The imaging team
is based at the Space Science Institute, Boulder, Colo.
Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jia-rui.c.cook@...
Joe Mason 720-974-5859
Space Science Institute, Boulder, Colo.
jmason@...
2009-176
Cassini Significant Events
for 11/11/09 - 11/17/09
The most recent spacecraft telemetry was acquired
on Nov. 17 from the Deep Space Network tracking
complex at Canberra, Australia. 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/mission/presentposition/ .
Wednesday, Nov. 11 (DOY 315)
Based on analysis of the preliminary data, the
Navigation Team proposed the cancellation of
Orbit Trim Maneuver (OTM) #222, planned to
execute on Nov. 12. This was approved by the
project. NAV also noted that it might be possible
to cancel OTM-223. Cancellation was contingent
upon an update to Enceladus pointing and
agreement by the various instrument teams.
Science Planning performed an OTM cancellation
assessment based on a preliminary spacecraft
ephemeris without the maneuver in it. The results
are very clear: an unplanned Live Inertial Vector
Propagator (IVP) update for Enceladus would need
to be performed should both OTMs be canceled. The
instrument teams completed their evaluation of
the proposed pointing update to Enceladus and
Rhea vectors on DOY 324-325 during the Enceladus
8 flyby period. The unplanned live update is a
go, and OTM-223 has also been cancelled.
In addition to the Live IVP update mentioned
above, Uplink Operations held a kickoff meeting
for the Radio Science (RSS) Enceladus 8 Live
Update Block (LUB) on DOY 324. RSS has evaluated
the most recent data and no updates will be
required to the product developed alongside the
background sequence development in October. These
files will be uplinked to the spacecraft on Nov. 18.
Thursday, Nov. 12 (DOY 316):
A news note on the Cassini Web page highlighted
an image of the massive bright clouds of tiny ice
particles hovering above the darkened rings of
Saturn. The picture was taken on Sept. 22, around
the time of Saturn's equinox, when the icy
particle clouds appeared particularly dramatic
because of the unique lighting geometry of the
equinox period. These levitating icy particle
clouds, which are known as "spokes," have a
radial extent of up to 10,000 kilometers. For the
complete text of the feature link to:
http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20091113/
Judges have selected the U.S. winners for the
Cassini Scientist for a Day essay contest.
Details on the contest, selected essays, and images can be found at:
http://saturn.jpl.nasa.gov/education/scientistforaday8thedition/sfad8thview/
Friday, Nov. 13 (DOY 317):
Science and engineering teams delivered files for
the third and final input port for the S58
Science Operations Plan process. The files have
been merged and released for review. The process
concludes Nov. 30 with the final development
process - the Science and Sequence Update Process -
beginning the following week. S58 execution begins
March 1, 2010.
The S54 sequence concluded and S55 began
execution today at 2009-315T12:44 PST. The
sequence will run for 39 days and conclude on
Dec. 22. During that time there will be two
targeted encounters, one of Enceladus and one of
Titan, and six non-targeted flybys - one each of
Helene, Pandora, Titan, Calypso, Rhea and
Pallene. Six maneuvers are scheduled, numbered 223
through 228.
Science at the start of S55 included observations
for an Optical Remote Sensing Titan cloud
monitoring campaign. Imaging Science then
observed the dark-side of Saturn in search of
lightning, obtained images of the transits of
Titan across Hyperion and Enceladus across Rhea
for orbit determination purposes, conducted
Saturn wide angle camera photopolarimetry
observations, and imaged a couple of stars as
part of a charge transfer calibration.
Magnetospheric and Plasma Science (MAPS)
instruments continued with the solar wind-aurora
campaign, and began a magnetospheric boundaries
campaign. The Ultraviolet Imaging Spectrograph
performed observations as part of a large
campaign to measure Saturn's magnetosphere at
apoapsis, and took a distant look at Enceladus to
map volatiles in the immediate neighborhood.
These observations will test the connection of
volatile changes to plume eruptions.
Tuesday, Nov. 17 (DOY 321)
An encounter strategy meeting was held today to
cover the period between Nov. 21 and Dec. 12,
Enceladus flyby E8 and Titan flyby T63, and
maneuvers 224 - 226. Navigation has determined
that maneuver #224 is a good candidate for early
uplink. After examining the schedule, it appears
that there are two DSN passes early Saturday
morning after the main engine cover is reopened that would work.
Visit the JPL Cassini home page for more
information about the Cassini Project:
http://saturn.jpl.nasa.gov/
------------------------
http://www.jpl.nasa.gov/news/features.cfm?feature=2372
Cassini Sends Back Images of Enceladus as Winter Nears
Jet Propulsion Laboratory
November 21, 2009
NASA's Cassini spacecraft has sailed seamlessly through the Nov. 21
flyby of Saturn's moon Enceladus and started transmitting uncalibrated
temperature data and images of the rippling terrain. These data and
images will be processed and analyzed in the coming weeks. They will
help scientists create the most-detailed-yet mosaic image of the
southern part of the moon's Saturn-facing hemisphere and a contiguous
thermal map of one of the intriguing "tiger stripe" features, with the
highest resolution to date.
"These first raw images are spectacular, and paint an even more
fascinating picture of Enceladus," said Bob Pappalardo, Cassini project
scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The
Cassini teams will be delving into the data to better understand the
workings of this bizarre, active moon."
Scientists are particularly interested in the tiger stripes, which are
fissures in the south polar region, because they spew jets of water
vapor and other particles hundreds of kilometers, or miles, from the
surface. This flyby was scientists' last peek at the tiger stripes
before the south pole fades into the darkness of winter for several
years. The thermal imaging work focused on the tiger stripe known as
Baghdad Sulcus.
The Nov. 21 encounter, which is sometimes called "E8" because it is the
eighth targeted flyby of Enceladus, brought Cassini to within about
1,600 kilometers (1,000 miles) of the moon's surface, at around 82
degrees south latitude. Cassini is now cruising toward Rhea, another one
of Saturn's moons, for more imaging and mapping work.
To see a full gallery of raw images, click here
<http://saturn.jpl.nasa.gov/photos/raw/>. For more information on the
flyby, click here
<http://saturn.jpl.nasa.gov/mission/flybys/enceladus20091121/>.
[Image]
Unprocessed image from Cassini's Enceladus flyby
This unprocessed image was captured by NASA's Cassini spacecraft during
its Nov. 21, 2009 flyby of Saturn's moon Enceladus. It shows the ridges
and fractures on the surface of the icy moon. Image credit:
NASA/JPL/Space Science Institute
Full image and caption
<http://www.nasa.gov/mission_pages/cassini/multimedia/cassini-b-20091121.html>
enlarge image
<http://www.jpl.nasa.gov/images/cassini/20091121/cassini20091121-b-full.jpg>
http://saturn.jpl.nasa.gov/mission/flybys/enceladus20091121/
Cassini
Enceladus Flyby - Nov. 21, 2009
E-8: Cassini Returns to the Tiger Stripes
On Nov. 21 Cassini will again fly by Enceladus, this time with a very
different geometry, approaching within 1,606 kilometers (997.9 miles) of
the surface. The closest approach will occur over 82 degrees south
latitude.
The spacecraft will again be under the control of thrusters during the
flyby, to allow for precise tracking of surface features during
closest-approach; the Composit Infrared Spectrograph (CIRS) instrument
will make a map of thermal emission from the tiger stripe Baghdad Sulcus.
This is the eighth targeted flyby of Enceladus; the flyby is sometimes
referred to as "E-8."
Enceladus Flyby
Nov. 21, 2009 (SCET)
Altitude
1,606 kilometers (998 miles)
Speed
7.7 km/sec (17,200 mph)
Details
+ Mission Description (PDF, 1.2 MB)
<http://saturn.jpl.nasa.gov/files/20091102-21_enceladus_mission_description.pdf>
http://pluto.jhuapl.edu/news_center/news/111209.php
New Horizons Roused for Long-Distance Checkup
November 12, 2009
Call it a burst of activity between naps: the New Horizons team woke
its Pluto-bound spacecraft from hibernation this week for some onboard
housekeeping.
On pre-programmed commands from controllers at the Johns Hopkins
University Applied Physics Laboratory in Laurel, Md. - transmitted to
the spacecraft in August through NASA's Deep Space Network of antenna
stations - New Horizons came out of hibernation on Nov. 9. The
spacecraft had been "sleeping" since Aug. 27, when it completed its
third annual instrument and system checkout.
"Although we hibernate about 90 percent of the time from August through
May each year, between checkouts we wake the spacecraft up in November
and January to re-point its antenna toward Earth and to conduct some
maintenance activities," says Mission Principal Investigator Alan Stern,
of the Southwest Research Institute. "So far, this wake up is going
smoothly."
Aside from turning the spacecraft's antenna, operators will also upload
some tweaks to New Horizons' fault-protection software. The team puts
the spacecraft back into hibernation on Nov. 20.
Distance milestone: Late tonight, New Horizons will reach 15
astronomical units from the Sun - the equivalent of 15 times the
distance from Earth to the Sun. Cruising between the orbits of Saturn
and Uranus, the spacecraft is speeding toward Pluto at 37,110 miles
(nearly 60,000 kilometers) per hour.
Cassini Significant Events
for 11/04/09 - 11/10/09
The most recent spacecraft telemetry was acquired on Nov. 10 from the
Deep Space Network tracking complex at Canberra, Australia. The
Cassini spacecraft is in an excellent state of health and all
subsystems are operating normally.
Wednesday, Nov. 4 (DOY 308)
Today a meeting was held to present and discuss the results of the
Enceladus 7 flyby. The Spacecraft Team used AACS telemetry data
gathered from the 100 km E7 flyby to derive an estimate of the
Enceladus plume density and of the torque experienced by the
spacecraft due to the plume. After reviewing results from AACS and
the Ion and Neutral Mass Spectrometer (INMS), the Project gave the go
ahead to do the E9 flyby on reaction wheels. INMS data was in good
agreement with the AACS analysis. The E9 flyby is nearly identical to
the E7 flyby, but with different instruments having pointing priority.
For the E9 flyby, Science Planning had asked all teams to deliver two
sets of input files, one for reaction wheels, and one for thrusters.
The version on thrusters will be archived and the reaction wheel
version will continue on in the sequence development process.
Thursday, Nov. 5 (DOY 309):
Orbit Trim Maneuver (OTM) #221 was performed today. This was the
cleanup maneuver from the Enceladus 7 encounter on Nov. 2. The main
engine burn began at 2:44 AM PST. Telemetry immediately after the
maneuver showed a burn duration of 1.73 seconds, giving a delta-V of
0.298 m/s. All subsystems reported nominal performance after the
maneuver.
After the S55 final sequence approval meeting was held today, eight
Instrument Expanded Block files were uplinked for five instruments
and Optical Navigation. The background sequence will go up to the
spacecraft on Monday.
A scientist on the Visual and Infrared Mapping Spectrometer team
wrote an update on the JPL Blog about the "First Morsels of Science"
coming back from the Enceladus flyby on Nov. 2. It is available at
http://blogs.jpl.nasa.gov/?p=58. The blog entry notes that mission
managers have cleared the spacecraft to do an April 28, 2010,
Enceladus flyby on reaction wheels, enabling scientists to do very
sensitive radio science measurements.
Friday, Nov. 6 (DOY 310):
At the S59 Science Forum on Nov. 2, it was pointed out that the Dione
2 flyby is only 1.5 days after the Titan 67 flyby, which brought up
an unlikely but not impossible scenario: If something were to happen
during or shortly after the T67 flyby such that the Project needed to
weigh the return of D2 science versus T67 science, which should be
considered of higher science importance?
To start the evaluation it is important to know that in this case the
Project regards the science on both flybys as important. Both Imaging
Science (ISS) and Composite Infrared Spectrometer (CIRS) observations
are tagged as being high priority science for both flybys. Science
Planning pinged members of the instrument teams to get their feedback
on, if they had to choose, which would it be? After reviewing the
responses, the answer was_ both flybys contain observations that are
at the highest priority. It would appear to be a draw. So now the
flight team would have to factor in what is happening operationally
at the time. There is no way in this still hypothetical case to
determine what the exact results would be, but factors in making a
decision include 1) what caused the incident, 2) is the DSN involved,
3) when is the next pass for downlink, 4) what is being kept on the
SSR, what is being overwritten, and when, 5) how much time does the
team have to decide, 6) is there time to command changes to what is
programmed in the background sequence, and, 7) are there other
scheduled onboard events that occur in the near term - such as a
maneuver or engineering activity - that might have an affect on the
plans that are made? It never is a simple decision, but at least the
flight team has given the matter some thought and will be prepared to
respond should it become necessary.
Monday, Nov. 9 (DOY 313)
The Target Working Team (TWT)/ Orbiter Science Team (OST) integrated
products for S60, covering orbits 131 through 133 in May and June,
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 Nov. 23. The handoff package template from
integration to the SOP process has been updated to better track more
involved prime-rider pointing designs, and two new milestones have
been added to the S60 schedule for prime-rider coordination. Between
now and the kickoff, the instrument teams will be working on pointing
designs for the sequence.
Participating teams delivered Port 1 SASFs today as part of the SOP
process for S59. As was mentioned earlier in this report, the files
include the Enceladus 9 flyby as designed for reaction wheels.
Tuesday, Nov. 10 (DOY 314)
An image of the recently illuminated north side of Saturn's rings was
Astronomy Picture of the Day today. Check it out at:
http://antwrp.gsfc.nasa.gov/apod/ap091110.html
Science in a nutshell: This week ISS obtained wide angle camera data
for Saturn photopolarimetry 1x2 mosaics, collected images for
satellite orbit determination, searched for lightning on Saturn, took
a look at the outer moon Bestla, observed the E-ring at low
resolution, low elevation, and high-phase, and obtained narrow angle
camera images of Titan's shadow on Saturn. Looking at the shadow of
Titan on Saturn is useful for Titan aerosol science. This is a unique
geometry that only occurs a few times during the Extended Mission and
not at all in the prime tour or proposed Extended Extended Mission.
CIRS wrapped up the far-IR hemisphere mapping activity, with scans of
the northern hemisphere and pole of Saturn, and measured oxygen
compounds - H2O, CO2 - in the stratosphere as a function of latitude.
Magnetospheric and Plasma Science (MAPS) instruments continued the
southwest auroral campaign, began a magnetospheric boundaries
campaign, and began a southwest auroral campaign to observe the
auroral magnetosphere and Saturn Kilometric Radiation source regions.
The Cosmic Dust Analyzer conducted an observation that is part of the
ISD survey campaign.
UVIS performed several apoapse system scans of the Saturn
magnetosphere and mapped volatiles in the immediate neighborhood of
Enceladus. These icy atmosphere observations test the connection of
volatile changes to plume eruptions.
Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>
------------------------
Cassini Significant Events
for 10/21/09 - 10/27/09
The most recent spacecraft telemetry was acquired on Oct. 27 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, Oct. 21 (DOY 294):
Wednesday, Thursday, and Friday saw the conclusion of the 49th
Project Science Group meeting held at JPL.
Onboard the spacecraft, the Cassini Plasma Spectrometer performed
three observations as part of the Solar Wind-Aurora campaign. The
Composite Infrared Spectrometer (CIRS) spent about 26 hours this week
mapping the northern hemisphere of Saturn to determine upper
troposphere and tropopause temperatures and executed a stray light
calibration. Sunlight falling on the CIRS telescope can possibly be
scattered into the instrument by mirror imperfections. To quantify
the effects of ring particle impacts on the mirror performance, CIRS
monitored the scattered infrared solar radiation as a function of the
offset angle from the sun. Imaging Science (ISS) spent about 25
hours searching for lightning on Saturn, observed the transits of
Rhea across Dione and Tethys, Enceladus across Tethys, and Titan
across Rhea. ISS also observed the outer moon Bestia for about 6
hours, performed a post equinox, edge-on observation of the E Ring,
and performed Saturn photopolarimetry with the wide-angle camera,
measuring the intensity and polarization of reflected light.
Thursday, Oct. 22 (DOY 295):
Both S55 and S56 are currently in the Science and Sequence Update
Process (SSUP), the final sequence development process before uplink
to the spacecraft. Today teams submitted any final Spacecraft
Activity Sequence Files (SASF) as part of the S55 Final Sequence
Integration and Validation phase. Changes this late in the process
are permitted for health and safety reasons only, rather than for
science enhancement. For S56, the first SASFs were delivered as part
of the Sub-Sequence Generation (SSG) process. Next week the
Preliminary Sequence Integration and Validation (PSIV1) cycle 1
merged background sequence products will be released along with the
stripped subsequences. These stripped subsequences are for review
purposes in the PSIV1 phase and the basis for the detailed
subsequences used to build the PSIV2 cycle 1 sequence products.
Monday, Oct. 26 (DOY 299)
The development process for the S54 E7 DOY 305 Live Update Block
kicked off today. A special orbit determination solution was
delivered at 4:00 PM; the Sequence Phase List of Ancillary Files was
out by 7 PM. The Go/No-go meeting will be Tuesday afternoon at 2:00
PM. The schedule is somewhat compressed as the uplink windows are
Friday night and Saturday night/Sunday morning.
Final products from the S57 Science Operations Plan process were
handed off from Science Planning to Uplink Operations today. The DSN
station allocation file has been posted for team access. Negotiations
are almost complete and are pending only the final two days.
Tomorrow the S57 SSUP kickoff/SSG waiver disposition meeting will be
held.
Tuesday, Oct. 27 (DOY 300)
The USTREAM TV archive of the Cassini scientists answering students'
questions about Saturn has received 630 views since it was posted one
week ago. This translates to up to 19,000 people, depending on how
many viewers were individuals versus classrooms of 30 students. To
view the video go to: http://www.ustream.tv/recorded/2391081.
An encounter strategy meeting was held today to cover the period
between Nov. 2 and Nov. 21, Enceladus flybys E7 and E8, and maneuvers
221-223.
The Cassini-Huygens Analysis and Results of the Mission (CHARM)
teleconference for October was held today. Topic: "The Search for
Activity on Icy Satellites that aren't Enceladus." The presentation
package is online and available at:
http://saturn.jpl.nasa.gov/video/products/MultimediaProductsCharm/
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Visit the JPL Cassini home page for more information about the
Cassini Project: <http://saturn.jpl.nasa.gov/>
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