Cassini Weekly Significant Events for 08/10/00 – 08/16/00
Cassini Weekly Significant Events
for 08/10/00 – 08/16/00
The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, 08/16. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Where is Cassini Now?" web page
( "http://www.jpl.nasa.gov/cassini/today/" )
This week’s activity onboard the spacecraft continued to center on the Command & Data Subsystem Flight Software (CDS FSW) Uplink and Checkout. The prime string has been successfully running the new (Version 7) software for over a week while the online (backup) string continues to execute the old (Version 5) software.
The Composite Infrared Spectrometer (CIRS) team has released preliminary results from the ICO2 quiet test held on July 26. Data indicate no interference was detected beyond the instrument’s own internal
interference. This is a very positive outcome for this test.
In light of Cassini’s fast approaching encounter with Jupiter and its joint observations with Galileo, two presentations on Galilean satellites were made at the Cassini Design Team Meeting. The first presentation "Icy Galilean Satellites" covered recent developments in the understanding of the surface compositions of the icy Galilean satellites—Europa, Ganymede, and Callisto. Most of the new results have come from the Near Infrared Mapping Spectrometer (NIMS) instrument on Galileo. Cassini’s Visual and Infrared Mapping Spectrometer (VIMS) instrument has about twice the spectral resolution as is available on Galileo. Thus, Cassini data from the flyby of Jupiter will enable a further refinement of the identification of the observed absorption bands.
"Constraints on Io’s Heat Flow" was the topic of the second presentation. Io is the most volcanically active place known. About the same size and density as the Moon, Io exceeds the Moon by about four orders of magnitude in heat production. The amount of heat flowing from Io’s interior is a fundamental constraint for modeling not only the interior of Io but also the interior of Jupiter, and the tidal evolution of the orbits of the satellites.
The Jupiter Science Planning Virtual Team (SPVT) implementation activity for C23 completed on August 11, and the product was delivered to the SVT to continue the final part of the sequence development process. This is the sequence that will be active on the spacecraft during the closest approach to Jupiter.
In preparation for the Jupiter Readiness Review to be held on August 25, developers for Jupiter capabilities met to review status and plans for all outstanding activities for this phase of the mission. Out of 25 development tasks originally scheduled for this phase, 19 are complete and 6 are still outstanding. No problems are anticipated in reaching planned readiness by the time of the review.
System Engineering coordinated a switch to new Multi-link Point to Point Protocol between JPL and Goldstone. This new protocol combines the "Big Pipe" and the "Little Pipe" (High volume flow and backup capability) providing a significant increase in available bandwidth for operational support.
Within the Science Opportunity Analyzer program, the need for new functionality was identified and is being investigated. Specifically, given a starting attitude, a turn and/or resulting attitude, it is planned to evaluate geometric constraints. This would allow prompt elimination of non-viable attitudes, and should speed up the "what-if" process.
Cassini Outreach
Cassini Mission to Saturn and Titan
Jet Propulsion Laboratory
California Institute of Technology
National Aeronautics and Space Administration
