ESAExoMarsHuman Spaceflight and ExplorationESA ScienceAurora Programme
   
Contents
PASTEUR PAYLOADHUMBOLDT PAYLOAD
ExoMars Mission
SummaryFactsheetScientific objectivesTechnical objectivesDevelopment history
Mission elements
The SpacecraftThe RoverThe Ground Segment
The Instruments
The team
Project team
Multimedia
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The ExoMars Instruments
 
The ExoMars science instruments are grouped into the Pasteur payload on the Rover and the Humboldt payload on the lander. The Humboldt payload was previously known as the GEP (Geophysical and Environmental) payload.
 
   
 
PASTEUR PAYLOAD
 
The Pasteur payload on the ExoMars Rover will accomplish the first and second science objectives of the ExoMars mission, and contribute to accomplishing the third. The Pasteur payload comprises: panoramic instruments for surveying the landscape to find scientifically compelling targets; contact instruments for studying outcrop and soil targets; and the analytical laboratory to characterise the organic substances and the geochemistry in the collected samples.

Panoramic instruments:

PanCam

The PanCam instrument consists in two main subsystems. The WAC (Wide Angle Camera) for multi-spectral stereoscopic panoramic imaging and the HRC (High Resolution Camera) for high resolution colour imaging. The main objectives of these cameras are:

  • To locate the landing site and rover position, support the ExoMars rover track planning and provide context information about the rover within its environment.

  • To geologically investigate and map the rover sites.

  • To study the properties of the atmosphere and of variable phenomena.
MIMA

The Martian Infra-red Mapper (MIMA) instrument is an infrared spectrometer based on the Fourier transform spectrometry technique. This instrument is mounted on the Rover's mast and works in collaboration with the PanCam for target selection.

The instrument has two different goals:

  • To determine from afar the bulk mineralogical composition of Martian surface targets and assist in the selection of specific rocks and soils to investigate in detail using other rover instrumentation.

  • To study the atmosphere to gather information about the meteorological conditions at the landing site and to measure gases this may point to biological activity.
The instrument is designed to measure rock, soil and atmosphere spectra with sufficient resolution to identify the spectral features of carbonates, phyllosilicates, sulphates, silicates, organic molecules, and minerals formed in water. The underlying scientific objectives are:
  • To reveal the record of Mars climate
  • To contribute to the search for life strategy
  • To study mineral groups in the Martian environment, and
  • To observe the Martian atmosphere
The design is based on the principle of double pendulum with corner cubes which has been successfully implemented in similar instruments designed and qualified for Mars Express (PFS) and Venus Express. MIMA designed to measure spectrum in the range 2 to 25 microns, thus two different detectors are used and mounted side by side in the same package.

The instrument can perform measurements in atmospheric mode or in geologic mode with different spectral resolution and the chosen principle make it easier the instrument manufacturing and integration in the rover's mast.
 
 
WISDOM

The Water Ice and Subsurface Deposit Information On Mars (WISDOM) instrument is a ground penetrating radar (GPR) operating in the UHF frequency range from about 500 MHz to 3 GHz with a relatively small radiofrequency (RF) output of 20 dBm.

Two Vivaldi antennas are used for transmission of the pulses and reception of the reflected signals. The electromagnetic waves transmitted by the radar will be reflected on subsurface targets that are formed by inhomogeneities in electrical parameters (permittivity, conductivity). Due to the relatively high frequency a penetration down to several meters can be expected (2 to 3 metres), similar to the depth reached by the Rover drill system for sample acquisition.

The radar uses the stepped frequency synthesis principle. For each emitted frequency the real and imaginary part of the return signal are processed and out of the N frequency responses the transfer function of the subsurface can be derived. With an inverse Fourier transform the synthetic time response of the subsurface can be computed.
 
 
Contact instruments:

CLUPI

The Close-Up Imager (CLUPI) is a highly integrated colour camera system with 3D packaging architecture. The camera can be divided into three parts: an electronics part with all the command electronics including the sensor package, a mechanical interface, and an optical assembly.

The scientific objective of CLUPI is to characterise the geological environment and to help to determine the details of the history and processes recorded in geologic materials at micrometer to centimeter scales. CLUPI will be used to determine the types of rocks present in the immediate surroundings of the ExoMars Rover on the basis of texture and to search for indications of former presence of water. This will contribute to the selection of sites for detailed investigation by drilling. In addition there is a potential to recognize morphological biosignatures and mineralized filamentous textures using CLUPI, leading up to more detailed investigations using the other instruments.

MIMOS II

The Miniaturised Mössbauer Spectrometer (MIMOS-II) takes advantage of the resonant absorption of recoil free emitted gamma-rays by certain nuclei (the Mössbauer effect). The instrument's radioactive source (57Co) decays via electron capture (nuclear process) to the Mössbauer state of 57Fe. This decay emits the 14.41 keV Mössbauer radiation with a high recoil free fraction.

A Mössbauer spectrum is a measurement of the intensity of the resonantly absorbed Mössbauer radiation as function of the Doppler-Velocity introduced by a moving source relative to the sample.

57Fe-Mössbauer spectroscopy determines directly the iron mineralogy of the target. In-situ analyses by the Mössbauer spectrometer provide the mineralogical composition of Fe-bearing surface rocks, sediments, and soils. The Mössbauer spectrometer is able to:

  • search for Fe-bearing sulphates, nitrates, and carbonates -> important irreversible volatile reservoirs. Their identification would aid in understanding water and climate evolution.

  • determine the Fe3+/Fe2+ ratio, which provides information on oxidation states providing insight into the nature of surface-atmosphere interactions, weathering processes, etc.

  • identify the iron oxides and the magnetic phase in the Martian soil - individual iron oxide and oxyhydroxide minerals have different chemical pathways of formation, and therefore form under different environmental conditions.

  • search for biomediated Fe-sulfides and magnetites - identification of concentrations of stoichiometric, defect free magnetite could provide evidence for former life on Mars.
The MIMOS instrument on ExoMars is an improved version of the successful Mössbauer spectrometers that flew to Mars with NASA's Spirit and Opportunity Mars Exploration Rovers.

Raman-LIBS (External Head)

The Raman/Laser-Induced Breakdown Spectroscopy (Raman/LIBS) instrument is accommodated in the analytical laboratory. However, an optical fibre bundle runs out to the robotic arm, where an external head for this instrument is mounted. The full description of the instrument capabilities is provided with the Analytical instruments.

MA_MISS

The Mars Multispectral Imager for Subsurface Studies (MA_MISS) is an infrared spectrometer instrument located in the drill. It includes the optical head of the spectrometer (in the drill box), a lamp to illuminate the borehole walls (in the drill tool), and the optical fibre that brings the signal from the drill tool up to the spectrometer in the drill box. The multispectral images are acquired by means of a sapphire window placed on the lateral wall of the drill tool, as close as possible to the drill head. The images are gathered by means of an optical fibre system and analysed using the spectrometer. The end to end optical fibre contains three de-mountable fixed joints (between the individual drill rods and on the rotational joint).

MA_MISS will be important for mineralogical studies. The composition of the regolith and crustal rocks provides important information about the geologic evolution of the near-surface crust, the evolution of the atmosphere and climate, and the existence of past or present life. Downhole measurements, allowing samples to be analyzed in situ, improves the understanding of the geologic context. The spectrometer integrated in the drill will help to answer the following open questions:

  • To understand the distribution and state of subsurface water and other volatiles.

  • To search for organic molecules and other potential indicators of past or present life.

  • To understand the geology and evolution of the upper crust and regolith (including lithology, composition, physical properties and structure).

  • To determine the nature and distribution of oxidants as a function of depth.

  • To characterize the geophysical environment and associated geophysical properties.
Analytical instruments:

Raman-LIBS (Internal Head)

The Raman – Laser-Induced Breakdown Spectrometer (Raman-LIBS) instrument combines the advantages of both techniques. In Raman spectroscopy, the vibrational transitions undergone by the chemical bonds of a compound are analysed after excitation by a monochromatic light source, normally a continuous or pulsed laser. In Laser-Induced Breakdown Spectroscopy (LIBS) the emitted electronic transitions of atoms ablated by small laser-induced plasma on the sample are analysed. Raman is sensitive to the phase (composition and structure) while LIBS is sensitive to the elemental chemical composition of any mineral or organic compound.
 
 
The instrument has four science goals. They are:

  1. to identify organic compound and search for life
  2. to identify the mineral products and indicators of biologic activities
  3. to characterize mineral phases produced by water related processes, and
  4. to characterize igneous minerals and their alteration products
The Raman-LIBS instrument will consist of one integrated spectrometer covering the spectral range 240-840 nm with a spectral resolution < 8 cm-1 for Raman measurements and < 0.2nm for LIBS measurements. Two excitation lasers will be used, one CW laser at 532nm for Raman and one pulsed laser at 1064 nm for LIBS. Detection will be made by a 2048 x 2048 pixels CCD. Two combined Raman-LIBS optical heads will perform analysis on the samples. Outside the rover the external optical head will analyse surface samples and eventually will perform ablation on coated materials for in-depth analysis.

Inside the Analytical laboratory the internal optical head will analyse surface and subsurface samples obtained by the drill system and prepared by the SPDS. Ablation capabilities could also be used in combination with the microscope for coated materials. The Raman-LIBS instrument will make the two in situ measurements on the same spot of a Martian target, thus the information at both atomic and molecular levels can be intrinsically combined into the investigation of that target. This enables the knowledge of mineral or molecular assemblages, of compositional partitioning among the species, of structural and compositional order-disordering to be obtained.

MicrOmega

MicrOmega is a visible / IR microscope designed to examine the collected samples to characterize their structure and composition at grain size level. These measurements will also be used to select sample locations for further analyses. MicrOmega is a integrated set of miniaturized systems consisting of:

  • One 4-colour (blue, orange, red, near IR) microscope providing for each sample full 1100x750 pixel images, with a 4 μm spatial sampling and with polarization capabilities; with such a resolution, key morphological structures for retrieving potential bio-records should be detected.

  • One near-infrared hyperspectral imaging spectrometer with a 5 mm field of view on the sample, and providing for each resolved 20 μm pixel, the full spectrum from 0.85 to 2.6 μm, in 500 contiguous spectral channels. From these image-cubes, and for each sample, all major and minor infrared-active constituents can be identified and mapped, at a grain scale. Key constituents include hydrated minerals: phyllosilicates, sulphates, carbonates, nitrates; Fe-oxides; Fe-bearing mafic silicates (olivine, pyroxene); organics: aromatics and aliphatics; H2O and CO2 ices.
A dedicated Electronics Unit controls and interfaces these two sensor units.

MicrOmega heritage flows from the successful development of instruments presently on board the ESA/Rosetta mission, or implemented within the Beagle2 Mars lander. The proposed optical microscope MicrOmega/VIS can be provided either with the existing spare systems of the Rosetta/Philae/CIVA and Mars Express/B2M microscopes, with mechanical and optical interfaces modified to fit the ExoMars configuration, or through new developments enhancing the performances. The near-infrared microscope MicrOmega/IR shares the design and many components of the near-infrared spectral microscope CIVA-M/I built at IAS for Philae, with adaptations that are presently being space qualified.

Mars-XRD

The Mars X-ray Diffractometer (Mars-XRD) uses a radio-isotope source to irradiate powdered rock samples with x-rays. The diffracted photons are measured on an array of CCDs and form a pattern in which resolved peaks are used in the identification of the mineralogical composition, by reference to a library of x-ray diffraction (XRD) data. XRD allows analysis of the textural and petro-mineralogic characteristics of samples, which the group hopes to exploit to examine the past Martian environmental conditions, and more specifically the identification of conditions related to life. Simultaneously to XRD, and using the same CCD array, the spectrum of the fluoresced photons is measured which allows elements within the sample to be identified.

The instrument target range for data analysis includes all the silicate minerals, from clays or other phyllosilicates characterised by high inter-planar lattice distance, to oxide and carbonates or evaporates (mainly sulphates). The determination of alteration processes will be used to assess historic environments. The identification of concentrations of carbonates, sulphides or other aqueous minerals may be indicative of a Martian hydrothermal system capable of preserving traces of life.

The instrument can also be used in the characterisation of Martian dust particles and of materials that may potentially be hazardous for human exploration.

MOMA

The task of the Mars Organic Molecule Analyser (MOMA) instrument is to detect and identify of as many molecular species as possible at low concentrations (that is ppb to ppt) with high analytic specificity. One application of MOMA is the use of a MOMA Gas Chromatograph Mass Spectrometer (GCMS) for the detection volatile molecules in atmospheric and sedimentary material.

Such organic molecules, which may come from the pyrolysis oven and the resulting gas are separated by a GC and then analysed individually with an ion trap mass spectrometer (ITMS), using electron ionization. The other option for less volatile molecules is to produce ions by high power laser pulses that desorb them from their embedding solid sample matrix. These ions are transferred from ambient Martian atmospheric conditions into the MS and analysed.

This method allows to investigate molecules which could otherwise not be volatilised and analysed in an MS and is therefore particularly useful for large and refractory organic material. GC-MS is in principle a two dimensional method of separating and identifying multi component gaseous samples The GC has the task to separate a gas mixture into a time series of individual components which are then analysed by an MS in series.

The separation is achieved by using long capillary tubes where the sample is pushed through by a carrier gas while it interacts with the inner wall coating of the tube. This phenomenon leads to different passing times for different molecular species provided the coating material is chosen appropriately. In the MS the effluent is then ionised, typically by electron impact, and the resulting ion fragments are analysed. The fragmentation patterns of molecules are well documented in large data bases and allow for a unique identification of molecules.

The idea to join these two initially independent instruments arose at the first Pasteur Working Groups Meeting in March 2004 at ESTEC. Both instruments contained a mass spectrometer with the respective vacuum system and it was therefore considered useful to combine the two. In the LD-MS experiment, a pulsed laser is focused onto the sample surface, at Mars ambient pressure, to desorb neutral and ionized molecules from a small spot.

In MOMA LDMS, this is accomplished by coupling the laser output into an optical focusing assembly which focuses the light at approximately 30 degrees incidence from normal, to an approximately 400 um spot. Samples are presented as drill fines loaded into a small cup within the sample handling system. The sample is put into a small container (with a volume of a few tenths of a cm3).

Depending on details to be finalized, there may be separate containers for pyrolysis/GC and laser desorption, to optimize these modes, however it is also possible to use a shared cup. Heating may be applied to the sample with or without the addition of a derivitization reagent, which produces volatile species for the GC-MS.

In the laser case the molecules (ions and neutrals) are transferred to the MS, with optional electron ionization of the neutrals, and mass analysed. In the pyrolysis case the molecules are transferred into the GC where they are separated in time by appropriate chromatographic columns and then introduced into the MS. Alternatively the pyrolysis gas sample may be directly fed into the MS, bypassing the GC. Helium is used as carrier gas for the GC, and therefore mixes with the CO2 damping gas for the ion trap MS.

The instrument design is based on a modular approach. This might be an advantage for the overall Pasteur payload volumes and lay-out optimization, in the Rover payload compartment. On the other side, it is proposed with the assumption to be able to use part of the Rover-Payload compartment structures for the mounting of the MOMA units and to share interface resources with the SPDS (e.g. ovens and tapping station).

Urey

The Urey instrument will search for organic compounds in Martian rocks and soils as evidence for past or present life and/or prebiotic chemistry. Urey will use a Sub-Critical Water Extractor (SCWE) to leach organics from rock/soil materials and deliver the enriched extract to the Mars Organic Detector (MOD) for an analysis of amino group compounds (amino acids, amines, nucleobases, amino sugars) and polycyclic aromatic hydrocarbons (PAHs). The detection will be by laser-induced fluorescence, a highly sensitive technique, capable of parts-per-trillion sensitivity. If amino acids are found, they will be further analyzed using the Micro-Capillary Electrophoresis Unit (μCE) to determine their chirality (right vs. left handedness). Chirality provides a basis for distinguishing between abiotic and biological sources of amino acids. These measurements will be made at a thousand times greater sensitivity than the Viking GCMS experiment, and will significantly advance our understanding of the organic chemistry of Martian soils.

A second component of the Urey experiment is the Mars Oxidant Instrument (MOI), which will perform complementary investigations of the oxidation state of Martian soils, while exploring for specific classes of oxidizing compounds. This experiment will look for correlations between the concentrations of organic compounds, oxidants, water abundance, and UV flux levels, as a function of depth in the subsurface at each ExoMars sampling site. The MOI will use a chemometric sensor array to measure the reaction rates of thin chemical films with differing sensitivities to oxidation. Films have been selected to target specific classes of oxidizing compounds expected to be present in the Martian surface environment, based on previous studies. By controlling the temperature of the coatings and their exposure to dust, ultraviolet radiation, light and water vapor, Urey will be able to determine the major processes and pathways of organic matter oxidation in Martian soils. One Urey MOI chemometric array is located inside the analytical lab, while a second array for dust studies in particular is foreseen on the outside of the rover, exposed to Martian atmospheric dust fall.
 
 
HUMBOLDT PAYLOAD
 
The Humboldt payload addresses the third and fourth scientific objectives by deploying instruments that will study the surface environment and the geophysics of the deep interior.

ARES

The Atmospheric Radiation and Electricity Sensor (ARES) will measure the electrical properties of the Martian environment. A set of electrodes accommodated on a shared boom is used to measure atmospheric electric fields and determine the ionization state (conductivity) of the Martian atmosphere. The atmospheric electricity and the related charging and discharging mechanisms are important for the understanding of many processes such as dust transport and deposition, atmospheric and surface chemistry, and aspects of habitability. Many electrification processes are closely related to the Martian weather conditions (wind, sunlight) and specific phenomena such as dust devils. Therefore the combination of ARES measurements and meteorological investigations (AEP/ATM) is considered to be very synergetic.

Overall, the main points addressed by the ARES measurements are:

  • Electrification processes
  • Conductivity (ionization) of the near surface atmosphere
  • Global electric circuit of Mars, Schumann resonances
  • Extra planetary electromagnetic fields
  • Coupling of meteorological phenomena and electric phenomena
  • Dust lifting / transport phenomena
  • Electrochemistry of lower atmosphere and surface
  • Charge related hazards for future missions
ATM

The AEP/ATM instrument comprises a set of meteorological and environmental sensors for the study of the Martian atmosphere, weather and environment. The sensors are accommodated on either a mast (temperature, wind, dust and humidity sensors) or on the Lander body (optical depth sensor, atmospheric pressure sensor). The ATM instrument addresses:

  • the study of the present-day atmosphere on Mars
  • the habitability of the environment
  • Mars climate evolution
  • Acquisition of engineering data for future missions
More specifically, the scientific topics include:
  • Studying the diurnal, seasonal and inter-annual variation of the measured parameters
  • Studying the structure of the planetary boundary layer
  • Investigating the processes of dust lifting and deposition
  • Provide support and environmental context measurements for other scientific investigations
  • Studying the Martian water cycle
For the Humboldt payload, a 1.2 m deployable mast is proposed, which is shared with the ARES team for accommodation of the ARES electrodes. Multiple miniature thermocouples, thermal wind sensors and humidity sensor are accommodated along this mast. The dust sensor film is mounted around the mast for sensing impacting dust particles. The optical depth sensor is connected to the outside via a fiberoptic cable.

EISS

EISS is a bi-static ground penetrating HF Radar for deep soundings from about 2 to 8 MHz, achieving kilometric depths. EISS consists of a Humboldt payload part (GPR1), an addition to the WISDOM on the Rover (GPR2), and an UHF synchronization link between both units. Low frequency impulses are transmitted from 35 m long kapton ribbon antennas lying on the ground, which are reflected on inhomogeneous subsurface layers. These reflected signals are received by the magnetic antennas mounted on the Rover for further analysis.

The GPR1 radar is also used in a mono-static mode by receiving reflected signals with the same antennas which are used for pulse transmission.

EISS is also foreseen to perform passive measurements to characterize the electromagnetic background and electrical discharge related natural emissions.

HP3

The Heat Flow and Physical Properties Package HP³ consists of three payload elements and one carrier system.

  1. TEM - thermal measurements
  2. DACTIL – tilt-and accelerometer package
  3. PP - permittivity measurements
  4. Mole – a soil penetrating device that carries the payload suite down to a depth of 5 meter.
The HP³ is designed for a depth resolved measurement of the key physical properties of the Martian regolith up to a depth of 5 metres.

During penetration, the Thermal Excitation and Measurement suite (TEM) of HP³ will obtain measurements of the regolith's thermal conductivity and diffusivity.

The Permittivity Probe (PP) will gather data on the soil’s dielectric constant or relative permittivity and electric conductivity.

The Depth, Accelerometry and TILt Measurement Suite (DACTIL), which will determine the mole’s movement and position, this will yield a depth-resolved section of the respective regolith parameters.

Once the final penetration depth has been reached, the TEM temperature sensors will be used for the long-term monitoring of the thermal environment at the landing site.

Together, these measurements will help to constrain the bulk density and porosity of the soil as well as its volatile content and its evolution with time.

Furthermore, the combination of temperature and thermal conductivity information will provide a measurement of the Martian planetary heat flow.

IRAS

The purpose of Ionizing Radiation Sensor (IRAS) is to fully characterise the ionizing radiation environment at the surface of Mars in view of future exploration by robots and humans. In the current design the detector head of the IRAS consists mainly of four planar silicon PIN-detectors (300μm thickness, outer diameter 42 mm) with an inner and outer segment. The distance between the upper two detectors is 25 mm. Detectors two, three and four are mounted very tightly together. The upper two silicon detectors will be used as a telescope which will provide particle and Linear Energy Transfer (LET) spectra for the ionising part of the radiation field. The inner part of the third detector records neutron interactions herby using its outer part plus the second and fourth detector as anticoincidence. Two additional PIN diodes are added in the electronic part beneath the detector head to provide measurements in x and y direction.

The operation of the system is managed by a microcontroller which controls the operation mode by switching the power and data lines to the individual sensors via a multiplexer on the main board, data sampling, internal intermediate storage and data transfer to the external main storage (located in the lower part of the container). The current size of the detector system is 72 mm in diameter and 81.5 mm in height, the mass is about 500 g, with a power consumption of 3000 mW.

The detector telescope will continuously monitor temporal variation of the particle count rate, the dose rate, particle and LET spectra. During operation two types of measurements will be performed: a) single detector mode for dose measurements in the individual detectors, b) coincidence mode for the measurement of particle and LET spectra in the range 2 to 2 000 MeV/cm.

Both measurements are integrations over software-defined time periods resulting in a reasonable data reduction/compression. LET spectra will be deduced from the energy deposit of coincident events in the silicon detectors. Since the incidence angle of the particles is not measured, the energy deposit is converted into LET in silicon, as energy deposited divided by the mean path length in the detector. The energy loss in water (tissue) relative to that in silicon is taken to be 1.21, independent of the particle energy. The neutron component will be determined by measuring the elastic and inelastic interactions in the third silicon detector. No signal in the anticoincidence detectors is required to attribute the interactions to neutrons.

LaRa

The X-band transponder for the Lander Radio Science Experiment (LaRa) is designed to obtain two-way Doppler measurements from the radio link between the ExoMars lander and the Earth during the ExoMars mission. These Doppler measurements will be used to obtain Mars orientation and rotation in space (precession and nutations, as well as length-of-day variations) as well as polar motion.

The ultimate objectives are to obtain information on Mars' interior and on the sublimation/condensation process of CO2. This is possible since one will be able to obtain the moment of inertia of the whole planet that includes the mantle and the core, the moment of inertia of the core, as well as the seasonal mass transfer between the atmosphere and ice caps.

The LaRa instrument is a coherent transponder using one uplink and one downlink in X-band. There is a corresponding ground segment in the experiment since the signal is observed by the DSN deep space network as well as by the ESA tracking stations. The complicated part of the experiment is the analysis of the data, which will be done using dedicated software built for the determination of the variations in Lander position as a function of time.

The LaRa experiment will be used to obtain the maximum amount of information about the interior of Mars and consequently about its formation and evolution, in complying with the ExoMars objective "To investigate the planet's deep interior to better understand Mars's evolution and habitability".

The instrument has two options for implementation: a small (20 Hz) or a large (5000 Hz) bandwidth transponder. The small bandwidth is the current baseline as it results in a better link budget (reduced noise bandwidth).
 
 
MEDUSA

The Mars Environmental Dust Systematic Analyser (MEDUSA) instrument consists of four different sub-systems;

  1. Dust optical detector
  2. Dust collector based on microbalance
  3. Water vapour detector based on microbalance
  4. Dust deposition and electrification sensor based on 6 lasers, photodiodes and electrical field measurements
The in situ characterisation of the dust and water vapour environment close to the Mars surface is the target of the MEDUSA instrument. In order to achieve this goal, the instrument has been designed to measure the following physical quantities:
  • Atmospheric dust particle size distribution
  • Number density of particles vs. size
  • Dust deposition rate
  • Dust electrical properties
  • Water vapour abundance in the atmosphere
  • Time evolution of the former quantities, vs. long term variations (seasons) and short term / local events (e.g. wind, dust storms)
The following basic choices have been adopted for MEDUSA:
  • A sampling device is used to avoid biasing effects on sample collection and selection of particle dimensions;

  • A dust cascade collector is considered integrating an optical detection device and a dust cumulative mass measurement system. The stages cover the required detection range;

  • Water vapour is detected with high sensitivity through a device similar to that used for dust cumulative mass measurement;

  • Dust deposition rate and electrification are determined using six laser-optoelectronic systems measuring the effects of dust electrification and gravity. Dust removal, electrical retardation and wind speed are also measured.
MiniHUM

The MiniHUM (miniature humidity) experiment is designed to obtain near-surface humidity- and frost-point temperature data on the ExoMars mission. The main scientific objectives to be addressed by the MiniHUM experiment are:

  1. To investigate the diurnal variation of the near-surface atmospheric water content at the landing site from trace amounts to saturation.

  2. To derive data about the water content of the upper surface soil layer(s) from its diurnal variation.

  3. To determine the atmospheric frost-point temperature (during phase transition) to independently derive the atmospheric water content (also as an independent calibration value) at that point.

  4. To study the water-related properties of the atmosphere-surface interaction processes.

  5. MiniHUM can support and deepen the value of the scientific measurements of other Pasteur instruments, e.g., by relating the atmospheric near-surface water content to other atmospheric and soil related thermo-physical parameters.
To appropriately place water-related and near-surface humidity and temperature measurements onboard Humboldt (part of the stationary descent module), it is necessary to have:

a.  the humidity sensor chip in close contact with the atmosphere but to be protected from dust by an appropriate coating,

b.  an external temperature sensor at the outer surface of the lander (in thermal radiation equilibrium with the environment, but without thermal contact to the lander).

MSMO

The Mars Surface Magnetic Observatory (MSMO) sensor is a fluxgate magnetometer which is employed to measure the near-surface magnetic field at the landing site. Together with information from a dedicated attitude sensor, the near-surface magnetic field data is used to investigate a range of phenomena in the Martian environment. The magnetic fields on Mars' surface consist of static components (crustal magnetic field) and dynamic components. While the determination static components may allow the correlation of landing site geology and geophysical properties, the analysis of the dynamic components will allow investigating the interaction of solar wind and other dynamic factors and the atmosphere. Overall, the main science goals are:

  • Observation of atmosphere / solar wind interaction, field line draping, magnetospheric properties.

  • Measurement of atmospheric escape by investigating the magnetospheric asymmetry.

  • Investigate the interaction of mini-magnetospheres and solar wind.

  • Investigate the effect of solar explosive events on the Martian environment.

  • Probing the planetary interior by observing induction effects.
SEIS

The Seismometer (SEIS) instrument uses 2 oblique very broad band sensors and 2 broad band short period micro-sensors. All together this system assembles a hybrid 3 axis seismic sensor in their overlapping band. Both sensor types rely on a proof mass which gets excited by external influence.

The instrument also includes thermal sensors inside and outside the compartments of both sensor system and one high precision sensor is located. Also a levelling system for the very broadband sensors is foreseen. The SEIS may be deployed from the lander with an arm or directly downward from the centre of the Lander if an arm is not available.

The SEIS instrument is designed to study the seismic activity of the planet by interior processes and in addition will detect the frequency of meteoritic impacts on the surface of Mars. Seismic events will be ranked according their magnitude and the source location will be determined by approximate distance and azimuth.

The following list of the foreseen scientific objectives is given by the SEIS team;

  • Determining the present seismic activity of the planet
  • Martian mantle attenuation (Q) and diffraction
  • Determining the present seismic activity of the planet
  • Determining the meteorite flux at the Martian surface
  • Determining the crust structure
  • Determining the presence of liquid water in the deep subsurface
  • Deep interior determination
  • Core structure
  • Mantle structure
UVIS

The Ultraviolet and Visible Spectrometer (UVIS) has the objective to measure at high resolution the Ultraviolet and visible radiation spectrum present at the Martian surface.

Included with UVIS is the Sun Sensor, a small photodiode-based instrument intended to obtain long term solar flux measurements over the mission lifetime. These measurements will provide new datasets, resulting in a better understanding of the hazards and dangers posed for future human exploration and the issue of extant life on Mars. These data will also provide supplemental data for the construction of Mars climate models, and to investigate the local Martian environment from an astrobiological and engineering point of view.

The design is mainly based on a commercial instrument, which is adapted and optimized for the space application. Hence it is not specifically designed (miniaturised) to fit in the smallest possible mass and volume allocation.
 
 
Last update: 1 February 2008

 


 
 
 
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