1. Bonn, 25 Jan 2005 Huygens at Titan Michael Bird Radioastronomisches Institut Universität Bonn

2. Bonn, 25 Jan 2005Huygens at Titan 2 Outline getting there 14 January 2005 lifting Titan’s veil Huygens DWE: an update

3. Bonn, 25 Jan 2005Huygens at Titan 3 getting there the journey is the destination.

4. Bonn, 25 Jan 2005Huygens at Titan 4 Cassini/Huygens

5. Bonn, 25 Jan 2005Huygens at Titan 5 Cassini/Huygens

6. Bonn, 25 Jan 2005Huygens at Titan 6 KSC, Cape Canaveral: 15 Oct 1997

7. Bonn, 25 Jan 2005Huygens at Titan 7

8. Bonn, 25 Jan 2005Huygens at Titan 8 Cassini SOI: 1 July at 02:36 UT

9. Bonn, 25 Jan 2005Huygens at Titan 9

10. Bonn, 25 Jan 2005Huygens at Titan 10 Christmas Day 2004

11. Bonn, 25 Jan 2005Huygens at Titan 11 14 January 2005 7 years, 3 months and 4 billion km from launch

12. Bonn, 25 Jan 2005Huygens at Titan 12 Huygens Descent on Titan From Atmospheric Entry To Touchdown on Surface

13. Bonn, 25 Jan 2005Huygens at Titan 13

14. Bonn, 25 Jan 2005Huygens at Titan 14 Huygens Targetting Error

15. Bonn, 25 Jan 2005Huygens at Titan 15 Huygens Landing Error

16. Bonn, 25 Jan 2005Huygens at Titan 16 Huygens: Descent Scenario

17. Bonn, 25 Jan 2005Huygens at Titan 17 Huygens events (UTC) One Way Light Time = 1 h 07 m 06 s EventSpacecraft Event Time (UTC) Earth receive time (UTC) Entry into Titan atmosphere09:06:5910:14:05 Deploy pilot parachute (t 0 )09:10:2110:17:27 Start Radio transmission09:11:0910:18:15 Huygens Signal Detection at Green Bank Telescope na10:25:00 Change parachutes09:25:2110:32:27 Impact on surface11:38:1112:45:17 End of link with Cassini12:50:2413:57:30 Last Huygens signal detection at Parkes Telescope na15:56:55

18. Bonn, 25 Jan 2005Huygens at Titan 18 Huygens Mission Intervals Predicted vs. Actual Interval Predicted Duration (hh:mm:ss) Actual Duration (hh:mm:ss) Descent Time02:15:0002:27:50 Cassini Link Time02:18:0003:40:03 Cassini Link from Surface00:03:0001:12:13 Total Observed Survival Time< 05:00:0005:38:55

19. Bonn, 25 Jan 2005Huygens at Titan 19 lifting Titan’s veil Yet do thy cheeks look red as Titan’s face W. Shakespeare

20. Bonn, 25 Jan 2005Huygens at Titan 20

21. Bonn, 25 Jan 2005Huygens at Titan 21 Titan: Pre-Cassini/Huygens (1) P Titan orbit = 15.9 d, P Saturn orbit = 29.4 yr, obliquity = 27° Bulk density = 1.88 g cm -3, ~ Callisto & Ganymede (~50% ice, ~50% rock) Atmospheric Composition: N 2 0.77 – 0.92 (0.97) Ar 0.05 – 0.17 (<0.001) CH 4 0.03 – 0.07 (0.023) other hydrocarbons and nitriles Haze from photodissociation of CH 4 :  = 2-5 in visible,  < 1 in near-IR. T surface = 94 K, P surface = 1.5 bar. Tropopause (42 km): T = 71 K; Scale height in troposphere = 20 km

22. Bonn, 25 Jan 2005Huygens at Titan 22 Titan: Pre-Cassini/Huygens (2) Mild Greenhouse Effect Optically Thick Aerosol Haze

23. Bonn, 25 Jan 2005Huygens at Titan 23 InvestigationAcronymPI Huygens Atmosphere Structure Instrument HASIM. Fulchignoni, Obs. Paris-Meudon (F) Descent Inager/Spectral Radiometer DISRM. Tomasko, U. Arizona, Tucson, AZ (USA) Gas Chromatograph / Mass Spectrometer GCMS H. Niemann, NASA/GSFC, Greenbelt, MD (USA) Aerosol Collector and Pyrolyzer ACP G. Israel, SA-CNES, Verrieres-de-Buisson (F) Surface Science PackageSSPJ. Zarnecki, Open U., Milton Keynes (UK) Doppler Wind ExperimentDWEM. Bird, U. Bonn (D) Huygens Investigations

24. Bonn, 25 Jan 2005Huygens at Titan 24 HASI atmospheric profiles pressure temperature T surf = 93.8 K P surf = 1.463 bar

25. Bonn, 25 Jan 2005Huygens at Titan 25

26. Bonn, 25 Jan 2005Huygens at Titan 26 GCMS Atmospheric Constituents

27. Bonn, 25 Jan 2005Huygens at Titan 27 ACP Schematic

28. Bonn, 25 Jan 2005Huygens at Titan 28 SSP: Impact on Surface ‘wet sand or clay’ (crème brûlée)

29. Bonn, 25 Jan 2005Huygens at Titan 29 DISR: first images ‘ dry’ lakebed drainage canals; fluvial activity fluid: CH 4

30. Bonn, 25 Jan 2005Huygens at Titan 30 DISR: Selected Details methane springs?water ice shoals?

31. Bonn, 25 Jan 2005Huygens at Titan 31 DISR: side-looking imager h: 8 km res: 20 m

32. Bonn, 25 Jan 2005Huygens at Titan 32 DISR: 360 Panorama ground fog h: 8 km;  s: 20 m horizontal velocity: 1-2 m s -1 landing site

33. Bonn, 25 Jan 2005Huygens at Titan 33 DISR: on the surface 85 cm 5 cm ‘orange tint from reflectance spectra’ ‘dirty water ice, not hydrocarbon ice’ ‘mouse’

34. Bonn, 25 Jan 2005Huygens at Titan 34 Huygens Doppler Wind Experiment: An Update

35. Bonn, 25 Jan 2005Huygens at Titan 35 DWE Concept Goal: In situ determination of zonal wind speed along Huygens descent path Approach: Record Doppler effect on Huygens carrier signal => radial velocity –Input parameters: 1.Huygens descent speed, meridional speed 2.Huygens starting position 3.Cassini position & velocity

36. Bonn, 25 Jan 2005Huygens at Titan 36 DWE Hardware TUSO on Huygens Probe RUSO in Huygens Receiver on Cassini Ultra-stable Oscillators (USOs)

37. Bonn, 25 Jan 2005Huygens at Titan 37 Huygens Doppler: PCO#1 TUSO/RUSO TCXO/TCXO 3 hours

38. Bonn, 25 Jan 2005Huygens at Titan 38 No power!

39. Bonn, 25 Jan 2005Huygens at Titan 39 DWE from Earth: Geometry Huygens antenna pointed only ~30° from Earth Better SNR than for Galileo Probe detection at Jupiter Probe velocity projection in direction to Earth nearly antiparallel to projection in direction to Orbiter

40. Bonn, 25 Jan 2005Huygens at Titan 40 GBT Parkes

41. Bonn, 25 Jan 2005Huygens at Titan 41 Earth-based DWE: Huygens Frequency Time (SPM) Impact on surface Change of parachutes GBTParkes

42. Bonn, 25 Jan 2005Huygens at Titan 42 prograde zonal wind

43. Bonn, 25 Jan 2005Huygens at Titan 43 VLBI network as seen from Titan: 14 Jan 2005

44. Bonn, 25 Jan 2005Huygens at Titan 44 VLBI station visibility entrylandingorbiterbattery GBT Parkes

45. Bonn, 25 Jan 2005Huygens at Titan 45 Huygens Art Contest

46. Bonn, 25 Jan 2005 Lebe Wohl, Huygens