TIMM-2

TIMM-2 is the solar occultation spectrometer to study the atmosphere of Mars in a number of spectral ranges between 2.3 and 4.1 µm with a resolving power / exceeding 20 000 across the spectral range.

TIMM-2 (Zelenyi et al, 2010, Marov et al., 2010) complements and enhances the capabilities of the AOST interferometer (Korablev et al., 2009) in solar occultation, providing a factor of 10 better spectral resolution, and a narrow FOV for several limited spectral intervals.

The experiment targets sensitive measurements of methane, profiling of Deuterium/Hydrogen, and other atmospheric gases (H₂O, O₃, CO, CO₂ isotopes, search for undetected species, potentially related to geophysical and exobiological activity), and the profiling and characterizing of aerosols.

  
TIMM-2 instrument optical bench

The instrument consists of two key elements: an echelle-spectrometer, and an acousto-optic tunable filter (AOTF) used for preselection of the diffraction orders. It is equiped of grating (24.4 gr/mm blazed at 70°) allowing a sampling of the spectral range (distant diffraction orders). It will be oriented parallel to the limb. To sound the UV, mostly to characterize the optical properties of aerosol, the instrument includes 5 channels at 250 (ozone), 340, 405, 520, and 700 nm. TIMM-2 mass is 3.5 kg, and requires 12W of power.

TIMM-2 instrument

TIMM-2 instrument elements details

TIMM-2 is conceived on the basis of the flight-proven instruments (SOIR on Venus Express, and RUSALKA on ISS), ensuring high heritage. It is built by IKI with the participation of LATMOS. This instrument is an addition to the Phobos payload due to the postoning of the launch. Its delivery is scheduled during the first quarter of 2011.