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Development of the Mars Microbeam Raman Spectrometer (MMRS),

a flight system for planetary missions

Basic criteria for an on-surface planetary analytical instrument:

A small volume, low mass, and low power consumption
B robust against the mechanical stresses of travel,  large excursions in temperature and pressure, strong vibrations
C function properly under the harsh environmental conditions of temperature cycling, vacuum or low or high atmospheric pressure, irradiation by cosmic radiation
D mechanically simple, with no or few moving parts.

Specific criteria for an on-surface Raman system:

A low background, high light throughput, and high sensitivity for mineral characterization
B two spectral regions:  200-1700 cm-1 (for oxyanions and carbonaceous materials) and 2500-4000 cm-1 (for hydrogen bonded to O, C, N, S etc.)
C wavenumber precision better than 2 cm-1,
D spectral resolution of about 4 cm-1
E internal standard for wavenumber calibration

A two-unit configuration for a rover- or lander-based Raman system: 

a lightweight, easily deployable probe attached to the arm of the rover or lander, and an energy analyzer mounted on the rover or lander body along with the electrical power supply and the data processor. The two parts are connected by an electrical cable for power and an optical fiber for signal transfer.

Referenece:  Wang et al., Applied Spectroscopy, Vol.52, P (1998)

 

Breadboard development at Washington University:

A breadboard model of the probe was first constructed in the laboratory at Wshington University to demonstrate the proof of design concept.

 

depth.JPG (372185 bytes) minerals.JPG (73270 bytes) rocks.JPG (214931 bytes)
Effective depth of sampling field: to enable system tolerance to natural rock and soil surfaces. Mineral tests:  These mineral spectra show the quality of our breadboard instrument. Rock tests: These rock samples are difficult specimens of types we might encounter on Mars.  They are  relatively fine-grained, and the original mineralogies of most of them have been altered by reaction with air and water.  The samples used were unsawn pieces with rough surfaces.

Reference: Wang A., Haskin A. L., Cortez E., “A Raman spectroscopic sensor for in situ mineral characterization on planetary surface”, Applied Spectroscopy (1998), Vol. 52, p477-487.

 

Development of MMRS at the Jet Propulsion Laboratory:

Breadboard 1a of the MMRS system

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spectrograph, detector, and electronics board typical spectra of minerals obtained by using BB1a

Initial brassboard of the MMRS system

laser (mounted) and  probe head (mounted on XYZ stage) spectrograph, detection system, and electronics

 

typical mineral spectra spectra of an impactite spectra of  carbonaceous materials in an ancient chert

Brassboard BB1d of the MMRS system

Reference: Wang A., Haskin L. A., Lane A. L., Wdowiak T. J., Squyres S. W., Wilson R. J., Hovland L. E., Manatt k. S., Raouf N., and Smith C. D. (2003) Development of the Mars Microbeam Raman Spectrometer (MMRS), J. Geophys. Res. , 108(E1), 5005, doi:10.1029/2002JE001902, 2003.

Advanced Brassboard of MMRS -- Current Status

 

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