Orbiter Instruments In Brief
ASPERA Energetic Neutral Atoms Analyser
The Earth and Mars, like the other planets, swim deep inside a plasma of charged particles (ions and electrons) racing outward from the Sun called the solar wind. ASPERA will study how the solar wind interacts with the Martian atmosphere and thus throw light on the mechanisms by which water vapour and other gases could have escaped from Mars in the past. The instrument will use a technique known as energetic neutral atom imaging to visualise the charged and neutral gas environments around Mars.
M. Holmström, Swedish Institute of Space Physics, Sweden
S. Barabash, Swedish Institute of Space Physics, Sweden
HRSC High/Super Resolution Stereo Colour Imager
The HRSC is a stereoscopic camera that will photograph the Martian surface to reveal detail as small as 2 m. The images will be used to produce a geological map showing the location of different minerals and rock types. The HRSC will make use of a modified second flight model of the High Resolution Stereo Camera originally developed for the Mars 96 mission.
R. Jaumann, Institute of Planetary Research, German Aerospace Center (DLR), Germany
MaRS Radio Science Experiment
MaRS will use radio waves to study both the surface and atmosphere. It will measure local variations in gravity over the surface of Mars and will provide pressure and temperature profiles of the atmosphere.
M. Pätzold, Rheinishes Institut für Umweltforschung, Universität Cologne, Germany
MARSIS Subsurface Sounding Radar/Altimeter
The primary objective of MARSIS is to map the distribution of water and ice in the upper portions of the Martian crust. Using techniques similar to oil prospecting on Earth, the instrument will analyse reflections of radio waves in the upper 2-3 km of Martian crust to reveal the subsurface structure. It will be able to distinguish between dry, frozen and wet soil.
R. Orosei, Istituto di Astrofisica e Planetologia Spaziali, Italy
J. Plaut, Jet Propulsion Laboratory, USA
OMEGA IR Mineralogical Mapping Spectrometer
Omega will determine the mineral content of the Martian surface and the molecular composition of the atmosphere by analysing sunlight reflected from the surface and diffused through the atmosphere. It will also perform similar analyses on heat radiation emitted from the surface. Information from Omega will contribute to our understanding of the structure of the Martian landscape and the role played by water over timescales ranging from seasons to billions of years. Like HRSC, OMEGA was originally developed for the Mars 96 mission.
J.-P. Bibring, Institut d'Astrophysique Spatiale - IAS Orsay, France
PFS Planetary Fourier Spectrometer
The Martian atmosphere consists mainly of carbon dioxide and nitrogen with a very small proportion of water vapour and ozone. PFS will measure the global atmospheric distribution of water vapour and other minor constituents with greater accuracy than previous missions.
M. Giuranna, Instituto Nazionale di Astrofisica, Italy
SPICAM UV and IR Atmospheric Spectrometer
SPICAM will measure the composition of the Martian atmosphere over smaller volumes than the PFS instrument. It will measure ozone using a technique similar to that used on the Mariner 9 spacecraft which first discovered ozone on Mars. SPICAM will also use the technique of stellar occultation, to measure the vertical profiles of carbon dioxide, temperature, ozone, aerosols and clouds.
F. Montmessin, Laboratoire Atmosphères, Milieux, Observations spatiales (LATMOS), France