Bob West

Saturn Activities, January-June 2014
• Detailed Planning – Saturn segments revs 209,
212 (executes 2014-279 to 2015-053).
• UVIS PRIMEs:
– 1 Stellar occ (Vega)
UVIS_209ST_ALPLYR001_PRIME
– 14 Auroral observations
– 1 UVIS_212SA_THERMOSPH001_PRIME
• 14 Riders with CIRS, VIMS – long integrations
1/8/14 UVIS Team meeting Caltech - Bob West 2

Saturn – AWG priorities within +- 1
Hour
• Gravity
– Saturn interior, penetration of zonal winds
• Magnetic Field (rotation rate)
• INMS Sampling (Neutral and ionosphere composition, ‘ring rain’
• High Resolution Radar radiometry (Thermal/NH
Imaging of clouds
3
) and ISS
• No UVIS priority within +- 1 hour
• Preliminary indications are that the time is oversubscribed
• Action items to find attitudes that serve more than one goal, such as RADAR and INMS.
• This activity lends itself to a TOST-like jumpstart.
1/8/14 UVIS Team meeting Caltech - Bob West 3

• Gravity, Mag and INMS done on separate perikrons
• One Saturn perikron +- 12 hours
1/8/14 UVIS Team meeting Caltech - Bob West 4

Saturn AWG Proximal Perikron SPASS
1/8/14 UVIS Team meeting Caltech - Bob West 5

Proximal Perikron Exercise
Lessons Learned
• CIRS and VIMS heating issues (from Saturn and rings) are not adequately handled by design software (PDT, KPT, etc.)
– With current flight rules, many things are impossible to plan iterate to a solution
– For this exercise we were instructed to ignore heating by Saturn and rings
– The issue is of major concern for VIMS and CIRS
– Some effort to improve the heating calculations (new model for CIRS) but the ultimate fidelity of the tool remains to be seen, and a VIMS model is unresolved.
1/8/14 UVIS Team meeting Caltech - Bob West 6

TOST Activities June 2013 – January 3, 2014
• Detailed planning T107 – T111 (executed 2014-
346 to 2015-128).
• UVIS Prime Requests in this period:
– 4 EUVFUV
– 1 Stellar Occ
• UVIS_208ST_ETAUMATI001_PRIME
• Numerous Rider observations, mostly with CIRS
– Any of these should request HDAC D-cell? Better coordination with Pascal Hedelt needed?
1/8/14 UVIS Team meeting Caltech - Bob West 7

1/8/14 UVIS Team meeting Caltech - Bob West 8

Triangles: already planned or executed
Diamonds: outside 12 R
S best for UVIS
Squares: inside 12 R
S
Tightly-packed squares at the equator are best for VIMS

From T. Koskinen, AWG meeting in
October, 2013
1/8/14
Purple diamonds: UVIS solar occs (Koskinen et al.2013), green squares: Voyager UVS occs (Smith et al.1983), black triangles: UVIS stellar occultations, dashed line: GCM (Müller-Wodarg et al.2012).
Above: P-T profile used by Moses et al.
(2000).
3 new occultations since PSG60 (near 20S, 20N)
UVIS Team meeting Caltech - Bob West 10

From T. Koskinen, AWG meeting in
October, 2013
Update:%Thermosphere%shape%
Left: Radius of the 0.01 nbar level from UVIS data (diamonds), 100 mbar reference level (Anderson and Schubert 2007). 21 UVIS occultations included.
1/8/14
Right: Altitude of the 0.01 nbar level above the 100 mbar reference, preequinox (green), post-equinox
(purple).
UVIS Team meeting Caltech - Bob West 11

F4: UVIS 2005 image of the Saturn thermosphere in non resonant H
2 emission
This image is an extraction from the same image cube as in F1. Bifurcation in H planetary atmospheres prior to the Cassini UVIS observations. H
2
2 protoplanetary disk systems. The emission shown here is excited at lower altitudes by photoelectrons and polar auroral electrons. Intensities are indicated on the image. Compare the strong polar emission in this image with F1. Heat deposition is weak in this component compared to the resonance shown in F1.
population structure has never been identified in solar system resonance structure has been observed in other objects such as
From Don Shemansky