Titan Flyby - 2 July 2006
29 June 2006
Forty three days after Titan-14, Cassini returns to Titan for its sixteenth targeted encounter (Titan-15). The closest approach to the moon occurs on Sunday, 2 July at 09:21 UT at an altitude of 1906 km above the surface and at a speed of 5.8 kilometres per second. The latitude at closest approach is -0.4° (near equatorial) and the encounter occurs on orbit number 25.This encounter is set up with two manoeuvres: an apoapsis manoeuvre on 7 June, and an approach manoeuvre, scheduled for 29 June. This outbound encounter occurs about 2 days after Saturn closest approach.
Science Activities
- Visual and Infrared Mapping Spectrometer (VIMS)
During the inbound leg, VIMS will make a global map of Titan. - Composite Infrared Spectrometer (CIRS)
CIRS will measure the trace constituents of CO, HCN, and CH4 in Titan's atmosphere during the Titan approach of T15. During the outbound leg, the CIRS instrument will perform vertical aerosol sounding of Titan's stratosphere, and conclude with measurements of trace constituents and thermal structure in Titan's stratosphere. - Imaging Science Subsystem (ISS)
The Narrow Angle Camera (NAC) will be making a global map of Titan during the inbound leg. The ISS instruments will monitor and perform a night side search for lightning/aurora on Titan during the outbound leg. - Cassini Radar (RADAR)
At 5 hours before Titan closest approach, the Cassini Radar will be placed in a passive mode called Radiometry, receiving energy emanating from the surface of Titan. This provides Cassini scientists with information regarding the moon's surface properties. At 1 hour 15 minutes before closest approach, the Radar will be switched to active mode to perform scatterometry measurements. Instead of creating Radar images, this mode of operation allows scientists to study the composition of Titan's surface. These Radar scatterometry measurements will only last 15 minutes, and then the spacecraft control is handed over to the MAPS instruments. - Magnetospheric and Plasma Science (MAPS)
The MAPS instruments will control the spacecraft attitude for 90 minutes around closest approach to perform in-situ measurements of Titan. Some of the MAPS teams consider this period to be ideal for analyzing the plasma wake structure around Titan, the escape of ions from Titan, and Titan's interaction with Saturn's magnetosphere. - Ultraviolet Imaging Spectrograph (UVIS)
During the outbound leg, UVIS will make scans across Titan's visible hemisphere.
Table of Events
3 June 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 02:39:00 | -29d 07h | Start of Sequence S21 which contains T15 |
28 June 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 16:07:00 | -03d 17h | OTM #64 prime, T15 minus 3 day targeting manoeuvre |
29 June 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 08:37:00 | -03d 01h | OTM #64 backup |
1 July 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 17:22:00 | -15h 58m | Start of the TOST segment |
| 17:22:00 | -15h 58m | Turn cameras to Titan |
| 17:52:00 | -15h 28m | Deadtime, used to accommodate changes in flyby time |
| 18:15:00 | -15h 05m | Infrared (IR) global mapping, search for and characterize clouds |
| 19:50:00 | -13h 30m | Far IR stratospheric studies, obtain information on CO, HCN, and CH4 |
| 23:20:00 | -10h 00m | Narrow Angle Camera (NAC) global map, global mosaic looking for cloud activity |
2 July 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 01:20:00 | -08h 00m | Mid IR limb observations, obtain information on trace constituents in stratosphere |
| 04:00:00 | -05h 20m | Turn RADAR toward Titan |
| 04:20:00 | -05h 00m | RADAR scatterometry and radiometry, study surface and sub-surface properties |
| 08:20:00 | -01h 00m | MAPS in-situ observations. Analysis of plasma wake, ions escaping from Titan, and Titan's interaction with Saturn's magnetosphere |
| 08:54:00 | -00h 26m | Titan wake crossing |
| 09:20:47 | +00h 00m | T15 flyby closest approach time; altitude=1906 km, speed=5.8 kms-1, 148° phase at closest approach |
| 09:50:00 | +00h 30m | Far IR limb observation, study stratospheric compounds, including H2O |
| 11:50:00 | +02h 30m | UV spectral imaging scans across visible hemisphere, analyze composition of upper atmosphere |
| 17:20:00 | +08h 00m | Visible observations of dark side, search for and monitor lightning/aurorae |
| 18:20:00 | +09h 00m | Far IR stratospheric studies, obtain information on CO, HCN, CH4 |
| 23:50:00 | +14h 30m | Mid IR stratospheric studies, analyze thermal structure (temperature map) |
3 July 2006
| Time UTC | Time wrt Titan-15 | Activity |
| 07:44:00 | +22h 24m | Deadtime, used to accommodate changes in flyby time |
| 07:52:00 | +22h 32m | Turn to Earth-line |
| 08:22:00 | +23h 02m | Begin playback of T15 data, Madrid 34M |
| 17:22:00 | +01d 08h | End playback of T15 data. Much of the T15 data will be returned during the playback on the following day |
Last Update: 1 September 2019
