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- Titans Purple Haze Points to a Fuzzy Past
- Cassini Significant Events for 22-28 July 2004
| On-board science activities this week included solar wind measurements by the Magnetospheric and Plasma Science (MAPS) instruments, Ultraviolet Imaging Spectrograph (UVIS) observations of Saturn's aurora and inner magnetosphere, and Imaging Subsystem observations of the southern hemisphere of Iapetus.
Spacecraft activities included a reaction wheel assembly bias and the removal of the Saturn Orbit Insertion critical sequence from the SSRs. This activity involved the uplink of several real-time commands over a period of three days. The procedure executed normally. The Cosmic Dust Analyzer discovered a dust particle carrying an electrical charge of almost 10 fC at a Saturn distance of 26 Rs and -16 degrees latitude. This is the first such detection in the Saturn environment, and the first since detection of particle charges in 2000. The charges of previous interplanetary particles were below 4 fC. The signal detected now is more than two times stronger and it is well above the detection threshold of about 1 fC. Science Operations Plan (SOP) Implementation of tour sequences S31/S32 has completed and a wrap up meeting is scheduled for next week. Official port #1 for SOP Implementation of S33/S34 occurred with the delivered files merged and the resulting products delivered to ACS for end-to-end pointing profile analysis. SOP Implementation for S35/S36 began this week. SOP update preliminary port#1 for tour sequence S05 occurred this week. The files were merged and a report identifying problem areas to be worked was generated and distributed to the team. The Integration and Test Laboratory has begun retesting the Probe Relay and Release sequences. This activity will be ongoing for several weeks. At the final sequence change request and waiver disposition meeting for S03, it was determined that a re-evaluation of star ID (SID) suspend commanding built for the sequence was needed. As there was margin remaining in the development schedule, it was decided to slip delivery of the final products, receipt of review of final products, delivery of the final package, and the final approval meeting by two days. ACS analysis subsequently showed no issues related to SID Suspend commanding. Final sequence products are now available, and the final Sequence Integration & Validation package has been distributed to the team. A command approval meeting (CAM) was held to approve 7 of the 9 instrument expanded block files to be uplinked to the spacecraft prior to the start of S03. The remaining files will be CAMed later in the week. A delivery coordination meeting was held this week for Telemetry, Tracking, Command & Data Management software v28.2.1. A Software Review / Certification Requirements meeting was held for Ion and Neutral Mass Spectrometer 9.0 flight software (FSW). This delivery includes the functions in an FSW patch that was applied during C44 and S01, as well as double buffering of the bus interface unit (BIU), use of DTSTART interrupt, and writing status information to BIU memory. The FSW was accepted for operational use with one follow-up action item. The software is scheduled to be uplinked to the spacecraft on September 1. On July 21, Cassini once again provided an image that was used as Astronomy Picture of the Day. This spectacular picture of the shadow of Saturn on the rings, along with all the most recent images may be viewed at http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. Titan's Purple Haze Points to a Fuzzy Past NASA image advisory 2004-187, 29 July 2004 Encircled in purple stratospheric haze, Saturn's largest moon, Titan, appears as a softly glowing sphere in this colorized image taken on July 3, 2004, one day after Cassini's first flyby of that moon. Titan has a dense atmosphere composed primarily of nitrogen with a few percent methane. The atmosphere can undergo photochemical processes to form hazes. Images like this one reveal some of the key steps in the formation and evolution of Titan's haze. The process is thought to begin in the high atmosphere, at altitudes above 400 kilometers (250 miles), where ultraviolet light breaks down methane and nitrogen molecules. The products are believed to react to form more complex organic molecules containing carbon, hydrogen and nitrogen that can combine to form the very small particles seen as haze. This ultraviolet view of Titan has been falsely colored. The main body is colored pale orange as seen in true color images. Above the orange disc are two distinct layers of atmospheric haze that have been brightened and falsely colored violet to enhance their visibility. It is not currently understood why there are two separate haze layers. This and other questions await answers as the four-year Cassini tour continues, with many more planned flybys of Titan. The upcoming October 2004 flyby of Titan will be 30 times closer than that of July 2. 
http://photojournal.jpl.nasa.gov/catalog/PIA06090 Image credit: NASA/JPL/Space Science Institute. For this and other images and information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini. Images are also available at the Cassini imaging team home page, http://ciclops.org. Cassini Significant Events for 22-28 July 2004 NASA/JPL release, 30 July 2004 The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, July 28. 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 http://saturn.jpl.nasa.gov/operations/present-position.cfm. On-board science activities included Ultraviolet Imaging Spectrograph observations of Saturn's aurora as well as solar wind measurements by the suite of Magnetospheric and Plasma Science instruments. Spacecraft events included the uplink of instrument expanded block files, the background sequence, and an ACS reaction wheel assembly bias all in preparation for S03. S03 begins execution on board the spacecraft on Friday July 30. A wrap up meeting was held for Science Operations Plan (SOP) Implementation of tour sequences S31/S32. The products have been archived and will resurface in February of 2007 for the start of the Aftermarket process. Analysis of the Port 1 S33/S34 products by the Attitude Control System Team has concluded. Teams are now making revisions for preliminary Port 2 next week. SOP update official port#1 for tour sequence S05 occurred this week. The files were merged and a report identifying problem areas to be worked was generated and distributed to the team. The Aftermarket decision meeting to determine what changes will be accepted for S07 was cancelled. The number of requested changes was less than the number of allocated work units for this sequence and is well within the resources of the team to implement. As part of S03 development activities, a command approval meeting was held for Cosmic Dust Analyzer flight software load files. These files will be uplinked to the spacecraft next week. Development of S04 continued with the publication of two versions of the Preliminary Sequence Integration and Validation (PSIV) Cycle 1 integrated sequence products. One version contained the background sequence only; the other version included the background sequence, a science mini-sequence, and an Ion and Neutral Mass Spectrometer mini-sequence. During the course of last week, 108 Cassini-related papers were presented at this year's Committee on Space Research (COSPAR) meeting in Paris, France. On Saturday, an all-day Cassini session was very well attended. Each team presented invited papers along with additional scientific papers. A Titan workshop is planned for early September at NASA's Goddard Space Flight Center. At this workshop the Cassini Orbiter observations of the atmosphere of Titan and other relevant ground-based observations will be reviewed. Participants will re-assess their understanding of the upper atmosphere of Titan with the specific objective of validating the engineering models of Titan's atmosphere that are to be used for the final Huygens probe release preparatory activities. The workshop is open to all Cassini-Huygens scientists and invited non Cassini-Huygens scientists. Check the Goddard web site for more information. Cassini Outreach participated in ASTROCON2004, a meeting of the Astronomical League (AL), Association of Lunar and Planetary Observers (A.L.P.O.), American Association of Variable Star Observers (AAVSO) and the Astronomical Society of the Pacific (ASP) July 20-24, 2004 in Berkeley CA. Around 300 mostly amateur astronomers from around the USA and from Finland and Australia attended. Cassini Outreach participated in a solar system panel discussion, provided outreach material for a JPL Solar System Ambassador display table, and visited several conference venues with Cassini connections. Chabot Space & Science Center (Oakland, CA) was showing Ring World, and had a model of Cassini prominently displayed near the entrance. Lick Observatory (San Jose, CA) staffers were shown the Cassini images of the Keeler Gap in Saturn's A ring. At the closing banquet aboard the USS Hornet aircraft carrier (Alameda, CA), speaker Apollo 12 astronaut Alan Bean was presented with a set of Cassini postcards and stickers. After looking at the images he commented to Cassini Outreach "What a successful mission Cassini is"! The Cassini Project Science Office hosted the first monthly telecon of science results from the mission this week. The Cassini-Huygens Analysis and Results of the Mission (CHARM) is an informal telecon where invited speakers discuss recent released findings from the spacecraft's 4-year tour of Saturn. Telecons are held on the last Tuesday of every month. The next scheduled CHARM telecon will occur Tuesday, August 31. Contact charm_leads@dcs04.jpl.nasa.gov for more information. The new Saturn Observation Campaign (SOC) worldwide members map can be seen on the SOC members' page at http://soc.jpl.nasa.gov/images/members-worldmap.gif. SOC currently has 340 members in 43 US states and also in 43 countries around the world. 
Cassini and Mars Outreach hosted the International Storytelling Center at CalTech this week. Scientists, engineers and outreach staff from both areas are participating in the event. A beautiful picture of Saturn's Rings was Astronomy Picture of the Day on July 23. Please link to http://saturn.jpl.nasa.gov for additional articles, images and information. 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 Office of Space Science, Washington, D.C. 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, CO. Contacts: Carolina Martinez Jet Propulsion Laboratory, Pasadena, CA Phone: 818-354-9382 Heidi Finn Cassini Imaging Central Laboratory for Operations Space Science Institute, Boulder, CO Phone: 720-974-5859 Additional articles on this subject are available at: http://www.astrobio.net/news/article1097.html http://www.astrobio.net/news/article1101.html http://www.spacedaily.com/news/cassini-04zzb.html http://www.spacedaily.com/news/cassini-04zzc.html http://www.spacedaily.com/news/saturn-titan-04r.html http://www.spacedaily.com/news/cassini-04zze.html http://www.spacedaily.com/news/cassini-04zzf.html http://spaceflightnow.com/cassini/040719dione.html http://spaceflightnow.com/cassini/040721rhea.html http://spaceflightnow.com/cassini/040722ringscolor.html http://spaceflightnow.com/cassini/040723tethys.html http://spaceflightnow.com/cassini/040726mimas.html http://spaceflightnow.com/cassini/040727titan.html http://spaceflightnow.com/cassini/040728titanhaze.html http://spaceflightnow.com/cassini/040730titanpurple.html http://www.universetoday.com/am/publish/tethys_revealed.html http://www.universetoday.com/am/publish/icy_enceladus.html http://www.universetoday.com/am/publish/saturns_death_star_mimas.html http://www.universetoday.com/am/publish/cassini_closer_to_titan.html http://www.universetoday.com/am/publish/cassini_crescent_view_titan.html http://www.universetoday.com/am/publish/titans_purple_haze.html http://www.universetoday.com/am/publish/icy_tethys.html Directory: projects -> marsbugs -> 2004 projects -> Rajinder Sachar Committee projects -> Cape Lookout National Seashore Historic Resource Study By projects -> Cape Lookout National Seashore Historic Resource Study By projects -> Revolutionizing Climate Modeling – Project Athena: a multi-Institutional, International Collaboration projects -> What is a Hurricane? projects -> General Information projects -> Press Information projects -> 1 Introduction 3 2 Designing an Embedded System 4 2004 -> Editor/Publisher 2004 -> Editor/Publisher Download 1.87 Mb. Share with your friends:
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