Status Report

NASA Cassini Significant Events 07/16/08 – 07/22/08

By SpaceRef Editor
August 1, 2008
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NASA Cassini Significant Events 07/16/08 – 07/22/08

The most recent spacecraft telemetry was acquired on July 22 from the DSN tracking complex at Goldstone, California. 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:

Wednesday, July 16 (Day of Year (DOY) 198):

The S47 kick-off meeting occurred today along with the port 1 delivery for S46. Each was part of the Science Operations Plan process for that particular sequence. The S46 files have been merged and reports sent out to the teams for review and resolution.

Have you ever noticed how you have to periodically reset your watch or clocks at home? The flight team has the same concern about keeping the clock on board the spacecraft synched up with time keeping here on Earth. This week the Mission Support and Services Office released two SCLKSCET or Spacecraft Clock Spacecraft Event Time files. These files incorporate two separate updates to the previous files: a nominal update to model the behavior of the spacecraft clock, and a leap second update, which goes into effect at the beginning of Jan. 1, 2009.

Sequence leads for S43 have determined that there are no remaining changes or outstanding issues for the development of this sequence. As a result, the existing products stand. There will be no updates between now and the final approval meeting scheduled for Aug. 5.

Thursday, July 17 (DOY 199):

An encounter strategy meeting was held today to cover the period between July 31 and Aug 11, Titan flyby T45 and Enceladus flyby E4, and maneuvers 162-163.

Friday, July 18 (DOY 200):

The second Cosmic Dust Analyzer (CDA) DOY 203 ring plane crossing demonstration sequence was uplinked today. Sequence leads will confirm the registration and activation of this file later today. The CDA DOY 201 Science and Engineering Record (S&ER) 2 telemetry (TLM) mode test uplinked yesterday has been verified as registered, activated on board, and is ready for execution on Sunday, July 19.

Following apoapsis, the Navigation Team took a few optical navigation images. Then the Ultraviolet Imaging Spectrograph (UVIS) looked at Saturn’s auroral zone at high latitude, with ISS and the Visual and Infrared Mapping Spectrometer (VIMS) riding along.

Monday, July 21 (DOY 203):

Over the weekend the CDA S&ER2 telemetry mode test executed. The first part of the test, under the old flight software version 10.3, ran successfully, but the results of the portion of the test running under the new V12.2 were inconclusive. CDA and the Sequence Leads have put their heads together and identified a window on July 26 where the second portion of the test can be rerun. The flight team wants confirmation that everything is working as planned well ahead of the Aug. 11, Enceladus flyby.

Good news for the second CDA ring plane crossing demonstration. Housekeeping data confirmed that the test ran as expected. CDA is waiting for the last of the bits to hit the ground to conclude their analysis of the results. So far it looks good.

Non-targeted flybys of Pallene, Atlas, Daphnis and Pan occurred today. In addition, the Radio and Plasma Wave Science (RPWS) subsystem executed an observation on thrusters to obtain wideband evidence of lightning whistlers.

Part two of the S42 background sequence was uplinked to the spacecraft today. It has been confirmed to be registered on board and will begin execution on Friday, July 25.

The Maine Engine (ME) cover was stowed – opened – today, concluding the 40th ME cover cycle since launch. This particular cycle was one of the longest with the cover deployed for 25 days since June 23. As always, the cover was deployed as a safeguard against possible dust hazards. The cover will next be deployed on July 27, 2008, at the end of the Orbit Trim Maneuver #160 prime uplink window, and will remain closed for only about 24 hours.

The third and final port for S45 occurred today as part of the Science Operations Plan process. This process concludes on Aug. 1 at which time the products will be handed over to Uplink Operations for the final sequence development process.

Tuesday, July 22 (DOY 204):

On July 22, 2008, AACS gave a presentation to project and section personnel on the status of the reaction wheels at the end of prime mission. The three wheels currently in use continue to function well, but are showing some signs of the effects of aging.

The schedule for the S42 DOY 209-210 Saturn/Tethys Live Inertial Vector Propagator Update was released today, and the kick-off meeting for this process was held.

Tomorrow the 2008 NASA Honor Awards ceremony will be held at JPL. These particular awards will be presented to individuals and groups at, or associated with, JPL who have made particularly significant contributions to the NASA mission over the past year. The Cassini Education and Public Outreach Team, RADAR Instrument Operations Team, and Titan Integration Science Team each will be honored with Group Achievement Awards. In addition, six members of the Cassini Flight Team will be awarded the Exceptional Engineering Achievement Medal, Exceptional Achievement Medal, or Exceptional Service Medal.

Coming Up:

JPL’s Office of Communications and Education is proud to present the 2008 Theodore von Karman Lecture Series. This month:

“Highlights of the Cassini Mission to Saturn” presented by the Cassini Project Manager, Thursday, July 24th in the Theodore von Karman Auditorium at JPL, Friday, July 25th, at Pasadena City College’s Vosloh Forum, 1570 East Colorado Boulevard. Both lectures are free and begin promptly at 7:00 PM, with seating available on a first come, first served basis. For more information about the event call the Public Services Office at 818 354-0112, or visit their web site at

SpaceRef staff editor.