Dust and water ice aerosols play a major role in the energy budget and circulation of the atmosphere of Mars and its climate. Dust affects the thermal structure and the dynamics of the atmosphere. Water ice clouds play an important part in the water cycle by altering the global transport of water vapor (Montmessin et al., 2004; Richardson & Wilson, 2002), by influencing the Martian climate radiatively (Madeleine et al., 2012; Wilson et al., 2008), and by changing the dust distribution through the scavenging of dust aerosols' particles due to the condensation of ice (Navarro et al., 2014; Pearl et al. 2001). Information on the aerosols physical properties is needed for a better understanding and modeling of Martian climate (

The ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO) was launched on 14 March 2016 and was successfully inserted into Mars' orbit in November 2016. After several orbit maneuvers including a 12-month aerobraking phase it reached its final, 400-km altitude and near-circular orbit on

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International audienceThe ACS package for ExoMars Trace Gas Orbiter is a part of Russian contribution to ExoMars ESA-Roscosmos mission. On the Orbiter it complements NOMAD investigation and is intended to recover in much extent the science lost with the cancellation of NASA MATMOS and EMCS infrared sounders. ACS includes three separate spectrometers, sharing common mechanical, electrical, and thermal interfaces. NIR is a versatile spectrometer for the spectral range of 0.7-1.6 μm with resolving power of ~20000. It is conceived on the principle of RUSALKA/ISS or SOIR/Venus Express experiments combining an echelle spectrometer and an AOTF (Acousto-Optical Tuneable Filter) for order selection. Up to 8 diffraction orders, each 10-20 nm wide can be measured in one sequence record. NIR will be operated principally in nadir, but also in solar occultations, and possibly on the limb. MIR is a high-resolution echelle instrument exclusively dedicated to solar occultation measurements in the range of 2.2-4.4 μm targeting the resolving power of 50000. The order separation is done by means of a steerable grating cross-disperser, allowing instantaneous coverage of up to 300-nm range of the spectrum for one or two records per second. MIR is dedicated to sensitive measurements of trace gases, approaching MATMOS detection thresholds for many species. TIRVIM is a 2- inch double pendulum Fourier-transform spectrometer for the spectral range of 1.7-17 μm with apodized resolution varying from 0.2 to 1.6 cm-1. TIRVIM is primarily dedicated to monitoring of atmospheric temperature and aerosol state in nadir, and would contribute in solar occultation to detection/reducing of upper limits of some components absorbing beyond 4 μm, complementing MIR and NOMAD. Additionally, TIRVIM targets the methane mapping in nadir, using separate detector optimized for 3.3-μm range. The concept of the instrument and in more detail the optical design and the expected parameters of its three parts, channel by channel are described. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only