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Titan Flyby - 12 December 2006

Titan Flyby - 12 December 2006

7 December 2006

After 48 days Cassini returns to Titan for its twenty-second targeted encounter, Titan-21. The closest approach to Titan occurs on Tuesday, 12 December at 11:41:31 UT, at an altitude of 1000 km above the surface and at a speed of 5.9 kilometres per second. The latitude at closest approach is 43.9° N (over the uncharted area known only as 'Belet') and the encounter occurs on orbit number 35.

This encounter is set up with two manoeuvres: an apoapsis manoeuvre on 26 November, and an approach manoeuvre, scheduled for 9 December. This inbound encounter occurs about 3 days before Saturn closest approach.

Science Activities

  • Cassini Radar (RADAR)
    RADAR obtains SAR (Synthetic Aperture RADAR) imagery of the poorly-covered northern mid-latitude trailing hemisphere, which may include some areas of dunes. This is the least explored area on Titan to date. Observations also include radiometry and scatterometry to build up southern hemisphere coverage.
  • Ultraviolet Imaging Spectrograph (UVIS)
    UVIS has a EUV-FUV observation, one of several throughout the tour, to image Titan at a variety of phase angles. These are used to investigate the scattering properties of high altitude aerosols, the latitudinal distribution of acetylene, methane, and some other hydrocarbons, and to look for auroral emissions. UVIS also observes an occultation of the star Alpha Per. Stellar occultations provide detailed vertical profiles of some hydrocarbons and haze in the altitude range 300 to 1500 kilometres. Each occultation samples a different latitude and different time of day so we gradually build up a 3-dimensional picture over the long term by observing many occultations.
  • Imaging Science Subsystem (ISS)
    The ISS outbound and inbound observations will image the surface of Titan and attempt to track atmospheric and surface changes. ISS will also be looking at surface colour variations and monitor limb hazes.
  • Magnetosphere and Plasma Science (MAPS) Working Group
    Analysis of plasma wake, ions escaping from Titan, and Titan's interaction with Saturn's magnetosphere down to a low altitude (1000 kilometres). INMS specifically will be looking at the atmospheric and ionospheric thermal structure of Titan's atmosphere.

Table of Events

24 November 2006 

Time UTC Time wrt
Titan-21
Activity
16:30:00 -17d 19h Start of sequence S26 which contains Titan-21 (T21)

30 November 2006

Time UTC Time wrt
Titan-21
Activity
13:44:00 -11d 22h Descending ring plane crossing

3 December 2006

Time UTC Time wrt
Titan-21
Activity
00:39:00 -09d 11h Ascending ring plane crossing

9 December 2006

Time UTC Time wrt
Titan-21
Activity
06:32:00 -03d 05h OTM #82 prime; Titan-21 minus 4 day targeting manoeuvre

10 December 2006

Time UTC Time wrt
Titan-21
Activity
06:32:00 - 02d 05h OTM #82 backup

11 December 2006

Time UTC Time wrt
Titan-21
Activity
15:17:00 - 20h 24m Start of the TOST segment
15:17:00 - 20h 24m Turn cameras to Titan
15:47:00 - 19h 54m Deadtime, 22 minutes long; used to accommodate changes in flyby time
16:08:31 - 19h 33m Titan atmospheric observations. Obtain information on the thermal structure of Titan's stratosphere

12 December 2006

Time UTC Time wrt
Titan-21
Activity
02:41:31 - 09h 00m Titan limb observations. Search Titan's nightside for atmospheric lightning and auras
04:11:31 - 07h 30m Titan atmospheric observations. Search Titan's nightside exobase to dayside exobase
10:31:31 - 01h 10m Stellar occultation. Observe the star Alpha Per as it is observed passing through Titan's atmosphere
10:57:31 - 00h 44m Transition to thrusters. The thrusters are needed to compensate for Titan's atmosphere torque and target motion compensation
11:18:31 - 00h 23m Sample Titan's upper atmosphere. INMS will attempt to determine atmospheric and ionospheric thermal structure.
11:41:31 + 00h 00m Titan-21 flyby closest approach. Altitude = 1000 km, speed = 5.9 kms-1; high phase inbound, 125° phase at closest approach, low phase outbound
11:41:31 + 00h 00m Titan outbound RADAR imaging. RADAR will obtain Synthetic Aperture RADAR (SAR) images of Titan's surface
11:56:31 + 00h 15m Titan outbound RADAR altimetry observations. Determine altitude of Titan's surface while the spacecraft is pointing nadir
12:10:00 + 00h 29m Descending ring plane crossing
12:11:31 + 00h 30m Transition to reaction wheels. The wheels are used for greater spacecraft stability
12:33:31 + 00h 52m Titan outbound RADAR scatterometry observations
13:18:31 + 01h 37m Titan outbound RADAR radiometry observations
15:41:31 + 04h 00m Full disk observations of Titan for surface and atmospheric mapping

13 December 2006

Time UTC Time wrt
Titan-21
Activity
01:09:31 + 13h 28m Deadtime, 5 minutes long; used to accommodate changes in flyby time
01:15:00 + 13h 34m Turn to Earth-line
01:36:00 + 13h 55m Begin playback of T21 data. Madrid 34M handover to Goldstone 70M
12:18:00 + 01d 01h End playback of T21 data

14 December 2006

Time UTC Time wrt
Titan-21
Activity
00:02:00 + 02d 12h Saturn periapse. R = 7.6 RS, latitude = -37°, phase = 23°

Observation Results

Cassini Instrument: Synthetic Aperture Radar (SAR)

Date:   12 January 2007

Credit: NASA/JPL

Image Notes: Two views (11 Dec. 2006 (T21), 29 Oct. 2005 (T8)) of a field of dunes located near 290° W, 9.4° S. Differences are due to change in the SAR illumination angle, revealing the surface make-up

Last Update: 1 September 2019
28-Oct-2021 13:22 UT

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