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), Moscow2 LATMOS, Guyancourt, France3 Physical faculty, Moscow State University4 Special Design Office of IKI, Tarusa, Kaluga reg.5 VNIIFTRI, Mendeleevo, Moscow reg.

• 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

Methane on Mars: detection from the Earth and PFS/Mars Express

Astronomical mapping of methane

Gemini-South, Keck-II telescopesEchelle-spectrometersMumma et al. 2009

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

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

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)

• CH4 (detection threshold <0.5 ppb, 20 times below present)

• HDO/H2O• Aerosol profiling

• Other minor species• CO2 isotopes

For methane: first CH4 measurements from the orbit around Mars after PFS:– Confirm detection– Confirm variability ?-limited mission time

For HDO:– First simultaneous measurements of HDO/H2O D/H (known from groundbased astronomy,

HDO and H2O 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 scenarioLaunch 8.11.2011 By Zenith from Baikonur Best date 11.11

Cruise 11.09.2012

3-day orbit 21.09.2012 800x75 900 km; 1.8° Release of YH-1

3-day orbit bis 30.09.2012 780x74 800 km; 1.5° Pericenter ascent

Intermediate orbit (3.5 d) 8.10.2012 6500x73 452 km; 1.1° Circularization

Observation orbit 14.01.2013 H=6470; T=8.27h; 1.1° 3 months; observation of Mars

Quasi-synchronous orb. 14.02.2013 5850x6100 km; T=7.65h 1 month; observation of Phobos

Landing 14.02.2013

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 (1.02.2011)

• 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

+XSun 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 CH4

and isolated HDO features• P4 line of methane (23 order)• No possibility for HCl, C2H6 etc

• CO2, H2O, CO well covered

Parameter High-resolution channel Photometric channels

Spectral range 2400 – 4200 nm 250 - 1500 nm

Resolving power, (/∆) > 20 000 30 - 150

Working spectral intervals 14 ranges ∆ = 14 – 23.5 nm 250, 340, 990, 1550 nm∆ = 10 nm

FOV 1.5×21 arc min Ø3.5 arc min

Spatial resolution at limb from Phobos orbit

60×2 km 10 km

AOTFTeO2, 20 - 40 MHz,

bandpass 20±0.5 cm-1,effectiveness 40% at 3390 nm

-

Echelle gratingNewport/RGL

24.355 gr/mm, Blaze angle 70°, Working area 46×96 mm

-

DetectorSOFRADIR

320×256 pixels 30×30 µm.Ricor-Thales Stierling cooler

Hamamatsu3 Si photodiodes 2x2 mm

1 InGaAs photodiode Ø1 mm

Power consumption Stand by 2 W.Operation12 W ave.

Memory RAM 8 Kbytes FIFO 256 KbytesFlash 256 Mbytes

Data rate Max 40 kb/s ; 22 Mb/session

Mass 2830 g

Dimensions 262×165×139 mm

folded optical scheme

main optical componentsmain optical componentsTelescope (Cassegrain, Al mirrors)

AOTF

HgCdTe 320x256 SOFRADIR MARS

MW detector (LATMOS)

Spectrometer

AOTF

f = A*+ B A B

AOTF1 0.009413481382539 -2.478479546760679

AOTF2 0.009406684896203 -2.458095239317771

Spectrometer

3.39 HeNe laser:λ/Δλ≈25000

Photometric channels

#q Target λ [nm] Δλ [nm]

Aperture, Ø [mm]

Diaphragm Ø [µm] Detector

6 Ozone 250 10 11 100 Si 2.4x2.4 mm Hamamatsu S1336-5BQ

8 Aerosol, ozone 340 10 8 100 -'-

5 Aerosol 990 10 3 100 -'-

7 Aerosol 1550 12 3 100 InGaAs Ø 1 mmHamamatsu G8370-01

1-4 Pointing monitoring 550 1 3 - Si 4x 1x1mm

ФД19КК

Flight unit

Electronic block diagramSIOK (S/C),

GCE

Controller MIL1553

TIMM

Service port

Controller

FPGA

AOTF

ADC

Photometers pointing sensor

SOFRADIRADC

FIFO

Flash

Ricor cooler

FPGA registers GCE

4/07/2011

Back-up

IR-spectroscopy

Spectral range 2,5 – 25 μResolution: 0.9 cm-1

Field of view - 2.3 deg Mass 4 kg

PI: O. Korablev, IKI

Fourier SpectrometerAOST

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 AOSTMode Solar occultation Atmosphere Surface

Spectral range, µm 2.5÷20 6÷25 2.5÷25

FOV 2.5°

Etendue m2sr 4.4 10∙ -7

Footprint Full solar disk0.35°

At Mars(in nadir from OO)

290 km

At Phobos(in nadir from QSO)

2.2 km

Optical Path Difference, cm 1.1 0.55 0.14

Spectral resolution, cm-1 0.9 2 7

Duration of observation s 5 50 50

Signal/Noise 100÷500 10÷500 10÷500

Interferogram lengths (number of points) 16384 8192 2048

Data rate, kb/spectrum 18 9 2.2

Mass, kg 4.1

Power consumption, WLess than stand-by

operation3

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

• CH4

• D/H

• aerosols