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TIMM: ECHELLE-SPECTROMETER TO STUDY THE ATMOSPHERE OF MARS

TIMM: ECHELLE-SPECTROMETER TO STUDY THE ATMOSPHERE OF MARS.

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TIMM: ECHELLE-SPECTROMETER TO STUDY THE ATMOSPHERE OF MARS

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  1. TIMM: ECHELLE-SPECTROMETER TO STUDY THE ATMOSPHERE OF MARS O. Korablev1, F. Montmessin2, A. Trokhimovsky1, A.A. Fedorova1, A.V. Kiselev1, J.L. Bertaux2, J.P. Goutail2, D.A. Belyaev1, A.V. Stepanov3,1, A.Yu. Titov4, Yu.K. Kalinnikov5, O.N. Andreev1, O.E. Kozlov1, A. Venkstern1. 1 Space research Institute (IKI), Moscow 2 LATMOS, Guyancourt, France 3 Physical faculty, Moscow State University 4 Special Design Office of IKI, Tarusa, Kaluga reg. 5 VNIIFTRI, Mendeleevo, Moscow reg.

  2. Methane on Mars: detection from the Earth and PFS/Mars Express • Krasnopolsky et al. 2004 • CFHT (3.6 m@ 4.2 km alt) FTS, resolution 0.017 cm-1 (ν/δν = 180,000) • 15 linesCH4 at 3.3 µm • Methane detected at 10 ± 3 ppb • PFS/MEX : resolution 1.2 cm-1 • Mean 10.5 ppb, variations 0-30 ppb

  3. Astronomical mapping of methane Gemini-South, Keck-II telescopes Echelle-spectrometers Mumma et al. 2009

  4. Methane detected ? Questions arising… • Biogenic/Abiotic sources • Rarified biota • Gas hydrate deposits • The 13С/12С ration in methane • Methane is photochemically stable (lifetime~300 y). What could explain its variability? • Sinks of methane? • Atmospheric electricity? • Resulting products  formaldehyde?  New measurements from the orbit and on the surface of mars are needed

  5. Recent measurements: EPSC-DPS in Nantes • Krasnopolsky (EPSC-DPS in Nantes from abstract): CSHELL/IRTF February 2006: methane below 10 ppb • Villanueva et al (EPSC-DPS in Nantes): CRIRES/VLT, NIRSPEC/Keck-2, CSHELL/IRTF 2009-2010: low upper limits for methane • PFS: Geminale et al. PSS 2011

  6. Trace gases in the atmosphere and new missions • Mars Science Laboratory (2011) rover • TDLAS in SAM (Webster&McHaffy PSS 2011) • Concentration and isotope measurements • ExoMars (ESA) Trace Gas Orbiter (2016) • MATMOS (JPL, Fourier occultation spectrometer) • NOMAD (Belgium +, Echelle spectrometer occultation + nadir) • Phobos-Grunt: • AOST: Fourier-spectrometer : 0.9 cm-1 in occultation • TIMM: Echelle spectrometer 0.1 cm-1 in occultation

  7. TIMM-2 = ТИММ • Echelle-AOTF instrument (similar to SOIR/VEX) • Main goal : methane detection and profiling in solar occultation • Added to the payload after the shift of launch to 2011 • Occupies the resources of Italian TIMM (thermal IR mapping of Phobos; was not delivered) • Delivered to Lavochkin Assoc in July 2011 and put on the s/c • Officially included in the payload: Aug 2011 • successful tests onboard: Sept 2011

  8. Science goals • Sensitive measurements of minor species (high signal/noise, high resolving power Δν~0.1 cm-1) • CH4(detection threshold <0.5 ppb, 20 times below present) • HDO/H2O • Aerosol profiling • Other minor species • CO2 isotopes • For methane: first CH4measurements from the orbit around Mars after PFS: • Confirm detection • Confirm variability ?-limited mission time • ForHDO: • First simultaneous measurements ofHDO/H2O  D/H (known from groundbased astronomy, HDOandH2Omeasured separately) • Vertical profiles • For aerosol: vertical profiling of optical properties in broad spectral range • determine size distributions • Together with AOST: determine the ratio of visible/thermal infrared opacity

  9. Mission scenario In the vicinity of Mars: Ls=170–264°. Global Dust Storm ?

  10. TIMM heritage Echelle+AOTF combination RUSALKA/ISS Made in IKI SOIR/Venus Express Made in Belgium

  11. Optical layout of the compact echelle-AOTF spectrometer

  12. TIMM-2 design drivers • Provide sufficient spectral resolution resolve methane and HDO/H2O features • Extremely limited development time (and budget) • Very limited space onboard (2010 passed essentially in negotiating the mechanical envelope) • Resulting largest dimension 260 mm • Empty place for TIMM-2 • Trying on the STM (1.02.2011) • 

  13. +X Sun direction TIMM LOS

  14. spectral coverage • Standard echelle grating (Newport/RGL): • loose spectral coverage + No influence of AOTF sidelobes + Most of minor species of interest covered

  15. TIMM orders Could not combine Q-branch of CH4 and isolated HDO features P4 line of methane (23 order) No possibility for HCl, C2H6 etc CO2, H2O, CO well covered

  16. folded optical scheme

  17. main optical components Telescope (Cassegrain, Al mirrors) HgCdTe320x256SOFRADIRMARSMWdetector (LATMOS) AOTF Spectrometer

  18. AOTF

  19. Spectrometer 3.39 HeNe laser: λ/Δλ≈25000

  20. Photometric channels

  21. Flight unit

  22. SIOK (S/C), GCE FPGA Controller Controller MIL1553 Photometers pointing sensor AOTF ADC Service port FPGA registers GCE SOFRADIR ADC FIFO Flash Ricor cooler TIMM Electronic block diagram

  23. 4/07/2011

  24. Back-up

  25. IR-spectroscopy Fourier Spectrometer AOST • Martian atmosphere • Methane, minor constituents (by Sun occultations) • Profiles of temperature; diurnal variations • Monitoring of aerosols • Martian soil • Discriminating chemically-bound and adsorbed water bands • Diurnal variations (temperature profiles, surface frosts) • Phobos • Global mineralogical mapping (from quasi-synchronous orbit) • Site spectrospy at cm-scale (after landing) Spectral range 2,5 – 25 μ Resolution:0.9 cm-1 Field of view - 2.3 deg Mass4 kg PI: O. Korablev, IKI

  26. Main parameters of AOST

  27. AOST: signal-to-noise and calibration spectra Estimation of S/N Laboratory BB spectrum (T=950°C; 5 s measurement)

  28. Occultation of sun by AOST CH4 D/H aerosols

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