Status Report

NASA Cassini Significant Events for 08/19/04 – 08/25/04

By SpaceRef Editor
August 28, 2004
Filed under , , ,
NASA Cassini Significant Events for 08/19/04 – 08/25/04

The most recent spacecraft telemetry was acquired from the Madrid tracking
station on Wednesday, August 25. The Cassini spacecraft is in an excellent
state of health and is operating normally. Information on the present
position and speed of the Cassini spacecraft may be found on the “Present
Position” web page located at .

At the beginning of this week, an encounter strategy meeting was held for
encounters Titan a, and Titan b. This included Orbit Trim Maneuvers (OTM)
2, 3, 4 (Ta-3), 5, 6, and 7. Immediately following, the OTM-2 maneuver and
command approval meetings were held.

On August 23, OTM-2, the periapsis raise maneuver, was successfully
completed. The purpose of this maneuver was to raise Cassini’s next closest
approach distance to Saturn on October 28 by nearly 300,000 kilometers. The
maneuver was necessary to keep the spacecraft from passing through the rings
and to put Cassini on target for its first close encounter with Saturn’s
moon Titan on October 26.

A “quick look” of telemetry immediately after the maneuver showed a burn
duration of 51 minutes, 8 seconds, giving a delta-V of 392.9 m/s. The
maneuver was the third longest engine burn for the Cassini spacecraft and
the last planned pressurized burn in the four-year tour. The Saturn obit
insertion burn in July was 97 minutes long, and the deep space maneuver in
December 1998 was 88 minutes long.

A new, special procedure for obtaining range points for navigation after
burn completion was used during this maneuver. The DSN transmitter was left
ON while the spacecraft was turned off Earth-point, and ranging disabled.
After the spacecraft came back to Earth-point, a Magellan acquisition or MAQ
was performed. This was done in order to obtain range points in the DSN
pass after the maneuver. The technique worked successfully.

Latch valve 10 was left open for 33 minutes after the burn completed in
order to further pressurize the oxidizer and fuel tanks for future
maneuvers. The propulsion team indicated the burn was fully pressurized
with the regulator performing normally. Tank pressures, latch valve
performance, etc, were normal. For more details on this maneuver refer to
the Cassini Website, News Release 2004-208 at Science activities this week included optical remote sensing (ORS) scans of
Saturn’s south pole as well as Ultraviolet Imaging Spectrograph mosaics of
Saturn’s magnetosphere. Imaging Science Subsystem (ISS) performed mosaics
and movies of the rings and Saturn’s south pole. Magnetospheric Imaging
Instrument (MIMI) imaged the magnetosphere and observed the solar winds and
pickup ions while the ORS instruments simultaneously observed Saturn’s
aurora. Magnetospheric and Plasma Science (MAPS) continued its campaign to
study the influence of the solar wind on Saturn’s aurora.

A wrap up meeting was held for the Science Operations Plan (SOP)
Implementation of tour sequences S33 and S34. The products have been
archived and will be available for use in April of 2007 when the S33
Aftermarket process begins.

A kick-off meeting was held for SOP Implementation of S37/S38. Preliminary
port #1 is scheduled for September 10.

The official port for SOP Update of S06 occurred this week. The products
have been merged and delivered to ACS for end-to-end pointing analysis.

The S04 Preliminary Sequence Integration and Validation-2 (PSIV) merged
sequence products were published for teams to review and for ACS to use for
Inertial Vector Propagator (IVP) & Kinematic Prediction Tool (KPT) inputs as
part of the Science and Sequence Update Process (SSUP). In addition,
instrument teams submitted their Instrument Expanded Block Spacecraft
Activity Sequence Files. For S05 development, PSIV1 Cycle 1 merged files
were placed in the Program file repository for team review, and a
Sub-Sequence Generation sequence change request approval meeting was held.

In the last week, 578 ISS images and 130 Visual and Infrared Mapping
Spectrometer (VIMS) cubes were acquired and distributed. So far since
Approach Science began, 18004 ISS images and 4914 VIMS cubes have been

A delivery review of Multi Mission Image Processing Laboratory software
version D32 was conducted this week. No concerns were brought up and the
delivery was accepted by all Projects. Instrument Operations personnel will
perform certification testing prior to releasing the software for
operational use by Cassini in early September.

The final scheduled release of the Cassini Information Management System
(CIMS) 3.2 has been installed for operations. The CIMS developers wish the
flight team a successful mission!

This week Cassini Outreach and Saturn Observation Campaign members supported
the Pasadena Public Library’s “Night Under The Stars” event. Sixty kids aged
5- 12 and their parents enjoyed telescopic views after dining on stars,
moons and crater dip punch. During the evening the traveling ” NASA @ your
library” exhibit was displayed featuring one exhibit-stand with six
flat-screen computers, and a plasma screen theatre showing NASA programming,
in addition to mission models and more. The exhibit opened August 13, runs
through September 19, and is open during all library hours.

For the most recent Cassini information, press releases, and images, go to .

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
Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington,
D.C. JPL designed, developed and assembled the Cassini orbiter.

SpaceRef staff editor.