TIMM: ECHELLE-SPECTROMETER TO STUDY THE ATMOSPHERE OF MARS O. Korablev 1, F. Montmessin 2, A. Trokhimovsky 1, A.A. Fedorova 1, A.V. Kiselev 1, J.L. Bertaux 2, J.P. Goutail 2, D.A. Belyaev 1, A.V. Stepanov 3,1, A.Yu. Titov 4, Yu.K. Kalinnikov 5, O.N. Andreev 1, O.E. Kozlov 1, A. Venkstern 1. 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.

Krasnopolsky et al CFHT ( km alt) FTS, resolution cm -1 (ν/δν = 180,000) 15 linesCH 4 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 Methane on Mars: detection from the Earth and PFS/Mars Express

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

Methane detected ? Questions arising… Biogenic/Abiotic sources –Rarified biota –Gas hydrate deposits –The 13 С/ 12 С 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

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 : low upper limits for methane PFS: Geminale et al. PSS 2011

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

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

Science goals Sensitive measurements of minor species (high signal/noise, high resolving power Δν~0.1 cm -1 ) CH 4 (detection threshold <0.5 ppb, 20 times below present) HDO/H 2 O Aerosol profiling Other minor species CO 2 isotopes  For methane: first CH 4 measurements from the orbit around Mars after PFS: –Confirm detection –Confirm variability ?-limited mission time  For HDO: –First simultaneous measurements of HDO/H 2 O  D/H (known from groundbased astronomy, HDO and H 2 O measured 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

Mission scenario Launch By Zenith from BaikonurBest date Cruise  day orbit  x km; 1.8°Release of YH-1 3-day orbit bis  x km; 1.5°Pericenter ascent Intermediate orbit (3.5 d)  x km; 1.1°Circularization Observation orbit  H=6470; T=8.27h; 1.1°3 months; observation of Mars Quasi-synchronous orb.  x6100 km; T=7.65h1 month; observation of Phobos Landing Return cruise~11 months In the vicinity of Mars: Ls=170–264°. Global Dust Storm ?

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

Optical layout of the compact echelle-AOTF spectrometer

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

+X Sun direction TIMM LOS

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

TIMM orders Could not combine Q- branch of CH 4 and isolated HDO features P4 line of methane (23 order) No possibility for HCl, C 2 H 6 etc CO 2, H 2 O, CO well covered

ParameterHigh-resolution channelPhotometric channels Spectral range2400 – 4200 nm nm Resolving power, ( /∆ ) > Working spectral intervals 14 ranges ∆ = 14 – 23.5 nm 250, 340, 990, 1550 nm ∆ = 10 nm FOV1.5×21 arc minØ3.5 arc min Spatial resolution at limb from Phobos orbit 60×2 km10 km AOTF TeO 2, MHz, bandpass 20±0.5 cm -1, effectiveness 40% at 3390 nm - Echelle grating Newport/RGL gr/mm, Blaze angle 70°, Working area 46×96 mm - Detector SOFRADIR 320×256 pixels 30×30 µm. Ricor-Thales Stierling cooler Hamamatsu 3 Si photodiodes 2x2 mm 1 InGaAs photodiode Ø1 mm Power consumptionStand by 2 W. Operation12 W ave. MemoryRAM 8 Kbytes FIFO 256 Kbytes Flash 256 Mbytes Data rateMax 40 kb/s ; 22 Mb/session Mass2830 g Dimensions262×165×139 mm

folded optical scheme

main optical components Telescope (Cassegrain, Al mirrors) AOTF HgCdTe 320x256 SOFRADIR MARS MW detector (LATMOS) Spectrometer

AOTF f = A* + B AB AOTF AOTF

Spectrometer 3.39 HeNe laser: λ/Δλ≈25000

Photometric channels #qTargetλ [nm] Δλ [nm] Aperture, Ø [mm] Diaphragm Ø [µm] Detector 6Ozone Si 2.4x2.4 mm Hamamatsu S1336-5BQ 8 Aerosol, ozone '- 5Aerosol '- 7Aerosol InGaAs Ø 1 mm Hamamatsu G Pointing monitoring Si 4x 1x1mm ФД19КК

Flight unit

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

4/07/2011

Back-up

IR-spectroscopy Spectral range 2,5 – 25 μ Resolution: 0.9 cm -1 Field of view deg Mass 4 kg PI: O. Korablev, IKI 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)

Main parameters of AOST ModeSolar occultationAtmosphereSurface Spectral range, µm2.5÷206÷252.5÷25 FOV2.5° Etendue m 2 sr4.4∙10 -7 Footprint Full solar disk 0.35° At Mars (in nadir from OO ) 290 km At Phobos (in nadir from QSO) 2.2 km Optical Path Difference, cm Spectral resolution, cm Duration of observation s550 Signal/Noise100÷50010÷500 Interferogram lengths (number of points) Data rate, kb/spectrum Mass, kg4.1 Power consumption, W Less thanstand-by operation 3 10

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

Occultation of sun by AOST CH 4 D/H aerosols