Cassini Significant Events 05/11/11 – 05/17/11

The most recent spacecraft telemetry was acquired on May 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, May 11 (DOY 131)

Orbit Trim Maneuver (OTM) #284 was performed today. This was the cleanup maneuver following Titan 76 and setting up for the Titan 77 encounter on June 20. The Reaction Control Subsystem (RCS) burn began at 11:45:30 PM PDT. Telemetry immediately after the maneuver showed a burn duration of 109.375 seconds, giving a delta-V of 0.120 m/s. All subsystems reported nominal performance after the maneuver. OTM-285, the first maneuver to target directly to the final T-77 aimpoint, is scheduled to execute next Monday evening (23 May).

The Command Autorad DSN Project Interface Test (PIT) planned for today was cancelled due to Extensible Markup Language (XML) file processing and Distributed Object Manager (DOM) publication issues between the Sequence Implementation Process (SIP) and Real Time Operations (RTO). The PIT will be rescheduled once these issues have been resolved.

Thursday, May 12 (DOY 132)

An image of Enceladus with Saturn’s atmosphere in the background was Astronomy Picture of the Day today. Check it out at: http://apod.nasa.gov/apod/ap110512.html

Friday, May 13 (DOY 133)

Port 2 products were due today as part of the S70 SIP. The products will be merged on May 17 and sent out to the flight team for review; the sequence is looking very clean.

Saturday, May 14 (DOY 134)

This week in science, the Imaging Science (ISS), Composite Infrared Spectrometer (CIRS), and Visual and Infrared Mapping Spectrometer (VIMS) instruments performed three 1.5-hr Titan cloud-monitoring observations; the three sets of measurements were separated in time to allow for temporal and longitudinal coverage. VIMS and CIRS also conducted a Saturn northern hemisphere mosaic observation to keep tabs on the giant storm currently raging there. Meanwhile, the MAPS instruments made measurements of the inner magnetosphere including during ring plane crossings (RPX), to monitor some of the different plasma regimes. The descending RPX occurred at 7.2 Rs while the ascending RPX was at 19.3 Rs. The VIMS instrument led an Optical Remote Sensing (ORS) ring-plane crossing observation near 10 degrees phase angle, and a measurement of the Saturn aurora was made by the Ultraviolet Imaging Spectrograph (UVIS) and the other ORS instruments. ISS performed a 14-hour observation of the outer irregular moon Suttungr (5.7 km across), and a 28 hour observation of another outer irregular moon, S/2004_S12 (5.2 km across). UVIS performed a three hour calibration by observing the star Spica, and did an 8-hour mosaic of Saturn and its surroundings in an effort to map hydrogen. The Magnetometer performed a 7 hour calibration while the spacecraft rolled about its X-axis. ISS made astrometric observations of some small inner moons including Calypso, Epimetheus and Prometheus.

Monday, May 16 (DOY 136)

A Cassini Solstice Mission Ground System risk assessment meeting was held today. The goal and purpose of this meeting were to identify where the Project stands relative to its longevity target for the ground system, lay out a road map for taking Project hardware and software to end of mission in 2017, and identify and assess any known risks and items that should be monitored to address any mitigation efforts required now.

Tuesday, May 17 (DOY 137)

The Cassini Deputy Project Scientist gave a presentation to members of the Project covering Cassini science results from the last quarter.