2003: Imaging spectrometer with an UV and IR channel. It aims at measuring the composition of the Martian atmosphere.
The SPectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM-Light) instrument is an imaging spectrometer with an UV (118-320 nm) and IR(1-1.7 µm) channel. Its goal on board Mars Express is the determination of the Martian atmosphere composition and temperature as a function of altitude. The mission was launched in June 2003. It received several mission extensions.
BIRA-IASB’s Engineering service was involved in the design, development and testing of hardware and mechanical subunits.
Launch: June 2, 2003
SPICAM-Light is a small UV-IR instrument selected for Mars Express to recover most of the science that was lost with the demise of Mars 96, where the SPICAM set of sensors was dedicated to the study of the atmosphere of Mars (SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars).
The new configuration of SPICAM-Light has a significantly reduced mass (“light”) and includes optical sensors and an electronics block. A UV spectrometer (118–320 nm, resolution 0.8 nm) is dedicated to nadir viewing, limb viewing and vertical profiling by stellar occultation. An IR spectrometer (1–1.7 µm, resolution 0.4–1 nm) is dedicated to vertical profiling during solar occultation. A nadir looking sensor is also included in the package. A simple Data Processing Unit (DPU) provides the interface of these sensors with the spacecraft.
Flight model of the SPICAM-Light instrument
In nadir orientation, SPICAM UV is essentially an ozone detector, measuring the strongest O3 absorption band at 250 nm in the spectrum of the solar light scattered back from the ground. In the stellar occultation mode, the UV Sensor will measure the vertical profiles of CO2, temperature, O3, clouds and aerosols. The density/temperature profiles obtained with SPICAM-Light constrain and aid in the development of the meteorological and dynamical atmospheric models, from the surface to 160 km in the atmosphere.
Flight model of the SPICAM-Light instrument
This is essential for future missions that will rely on aerocapture and aerobraking. UV observations of the upper atmosphere allow the study of the ionosphere through the emissions of CO, CO+, and CO2+, and its direct interaction with the solar wind. Also, it allows a better understanding of escape mechanisms and estimates of their magnitude, crucial for insight into the long-term evolution of the atmosphere.
Double shutter system of Spicam-Light (BIRA-IASB museum)
The SPICAM Light IR sensor is inherited from the IR solar part of the SPICAM-S solar occultation instrument of Mars 96. Its main scientific objective is the global mapping of the vertical structure of H2O, CO2, CO, HDO, aerosols, atmospheric density, and temperature by the solar occultation. The wide spectral range of the IR spectrometer and its high spectral resolution allow an exploratory investigation addressing fundamental question of the possible presence of carbon compounds in the Martian atmosphere.
An additional nadir near IR channel employs an Acousto-Optical Tunable Filter (AOTF) and is dedicated to the measurement of water vapor column abundance in the IR simultaneously with ozone measured in the UV.
The Sensor Unit has two openings for nadir viewing, one for the UV channel, the other for the IR channel located on the nadir face of the spacecraft. In addition, there is an opening for Solar viewing. This Solar aperture is not on the spacecraft nadir face.
The Sensor Unit has two mechanisms:
- one which moves on and off a slit in the UV channel,
- the other which moves a shutter on the Solar aperture.
The SPICAM-Light mechanisms are fully autonomous and no separate commands are needed for mechanism operations.
The UV channel is a spectrometer with an optical baffle, an off axis parabolic mirror, a slit with two positions, a grating and a detector which is an intensified CCD.
The IR channel is made of an entrance lens, an AOTF and two single pixel detectors (for each polarization). As the AOTF acts as a filter, the IR spectrum is obtained by electrically scanning the AOTF frequency. All the channels have their own digital electronics which performs all operations at detector level and digitizes the data, then waiting for transmission to the DPU.
Publications
- Bertaux, J.-L.; Korablev, O.; Fonteyn, D.; Perrier, S.; Fedorova, A.; Montmessin, F.; Leblanc, F.; Lebonnois, S.; Lefèvre, F.; Quémerais, E.; Rannou, P.; Chaurray, J.Y.; Forget, F.; Sandel, B.; Stern, A.; Muller, C.; Dimarellis, E.; Dubois, J.P.; Guibert, S.; Souchon, G.; Leclère, M.; Semelin, F.; Reberac, A.; Barthelemy, M.; Lebrun, J.C.; Taulemesse, C.; Van Ransbeeck, E.; Gondet, B.; Kiselev, A.; Rodin, A.; Stepanov, A.; Kalinnikov, Yu.; Grigoriev, A.; Hauchecorne, A.; Cabane, M.; Chassefière, E.; Cernogora, G.; Levasseur-Regourd, A.C.; De Maziere, M.; Neefs, E.; Simon, P.C.; Fussen, D.; Nevejans, D.; Arijs, E.; Hourdin, F.; Talagrand, O.; Witasse, O.; Kyrölä, E.; Tamminen, J. (2009), “Spicam: Spectroscopy for the investigation of the characteristics of the atmosphere of Mars”, ESA SP-1291: Mars Express: The Scientific Investigations, Vol. 1291, Issue , 139-197
- Korablev, O.I.; Bertaux, J.L.; Kalinnikov, Y.K.; Fedorova, A.A.; Moroz, V.I.; Kiselev, A.V.; Stepanov, A.V.; Grigoriev, A.V.; Zhegulev, V.S.; Rodin, A.V.; Dimarellis, E.; Dubois, J.P.; Reberac, A.; Van Ransbeeck, E.; Gondet, B. (2006), “Exploration of Mars in SPICAM-IR experiment onboard the Mars-Express spacecraft: 1. Acousto-optic spectrometer SPICAM-IR”, Cosmic Research, Vol. 44, Issue 4, 278-293, DOI: 10.1134/S0010952506040022
- Korablev, O.; Bertaux, J.-L.; Fedorova, A.; Fonteyn, D.; Stepanov, A.; Kalinnikov, Y.; Kiselev, A.; Grigoriev, A.; Jegoulev, V.; Perrier, S.; Dimarellis, E.; Dubois, J.P.; Reberac, A.; Van Ransbeeck, E.; Gondet, B.; Montmessin, F.; Rodin, A. (2006), “SPICAM IR acousto-optic spectrometer experiment on Mars Express”, Journal of Geophysical Research E: Planets, Vol. 111, Issue 9, E09S03, DOI: 10.1029/2006JE002696
- Bertaux, J.-L.; Korablev, O.; Fonteyn, D.; Guibert, S.; Chassefière, E.; Lefèvre, F.; Dimarellis, E.; Dubois, J.P.; Hauchecorne, A.; Cabane, M.; Rannou, P.; Levasseur-Regourd, A.C.; Cernogora, G.; Quémerais, E.; Hermans, C.; Kockarts, G.; Lippens, C.; De Maziere, M.; Moreau, D.; Muller, C.; Neefs, E.; Simon, P.C.; Forget, F.; Hourdin, F.; Talagrand, O.; Moroz, V.I.; Rodin, A.; Sandel, B.; Stern, A. (2005), “Global structure and composition of the martian atmosphere with SPICAM on Mars express”, Advances in Space Research, Vol. 35, Issue 1, 31-36, DOI: 10.1016/j.asr.2003.09.055
- Bertaux, J.-L.; Fonteyn, D.; Korablev, O.; Chassefière, E.; Dimarellis, E.; Dubois, J.P.; Hauchecorne, A.; Lefèvre, F.; Cabane, M.; Rannou, P.; Levasseur-Regourd, A.C.; Cernogora, G.; Quemerais, E.; Hermans, C.; Kockarts, G.; Lippens, C.; De Maziere, M.; Moreau, D.; Muller, C.; Neefs, E.; Simon, P.C.; Forget, F.; Hourdin, F.; Talagrand, O.; Moroz, V.I.; Rodin, A.; Sandel, B.; Stern, A. (2004), "SPICAM: Studying the global structure and composition of the martian atmosphere", ESA-SP 1240, Mars Express: the scientific payload, Issue 1240, 95-120
- Bertaux, J.-L.; Fonteyn, D.; Korablev, O.; Chassefière, E.; Dimarellis, E.; Dubois, J.P.; Hauchecorne, A.; Cabane, M.; Rannou, P.; Levasseur-Regourd, A.C.; Cernogora, G.; Quemerais, E.; Hermans, C.; Kockarts, G.; Lippens, C.; De Maziere, M.; Moreau, D.; Muller, C.; Neefs, E.; Simon, P.C.; Forget, F.; Hourdin, F.; Talagrand, O.; Moroz, V.I.; Rodin, A.; Sandel, B.; Stern, A. (2000), “The study of the Martian atmosphere from top to bottom with SPICAM light on Mars Express”, Planetary and Space Science, Vol. 48, Issue 12-14, 1303-1320, DOI: 10.1016/S0032-0633(00)00111-2
