NASA-CR-191638

WORKSHOP ON

Ii ql IOVATIVE INSTRUMENTATION

_OR THE IN SITU STUDY OF

ATMOSPHERE.SURFACE

INTERACTIONS ON MARS

MSATT

Mars Surface and Atmosphere Through Time

(NASA-CR-191638) WORKSHOP ON

INNOVATIVE INSTRUMENTATION FOR THE

IN SITU STUDY OF ATMOSPHERE-SURFACE

INTERACTIONS ON MARS (Lunar and

Planetary Inst.) 16 p

N93-16630

Unclas

63/91 0137598

LPI Technical Report Number 92-07, Part 2

LUNAR AND PLANETARY INSTITUTE 3600 BAY AREA BOULEVARD HOUSTON TX 77058-1113

LPI/TR--92-07, Part 2

WORKSHOP ON INNOVATIVE INSTRUMENTATION

FOR THE IN SITU STUDY OF

ATMOSPHERE-SURFACE INTERACTIONS ON MARS

Edited by

Bruce Fegley Jr. and Heinrich Wanke

Held at

Max-Planck-Institut ftir Chemie

Mainz, Germany

October 8-9, 1992

Sponsored by

The Lunar and Planetary Institute

The MSATT Study Group

Lunar and Planetary Institute 3600 Bay Area Boulevard

LPI Technical Report Number 92-07, Part 2

LPFTR--92-07, Part 2

Houston TX 77058-1113
Compiledin 1992 by

LUNAR AND PLANETARY INSTITUTE

The Institute is operated by Universities Space Research Association under Contract NASW-4574 with

the National Aeronautics and Space Administration.

Material in this document may be copied without restraint for library, abstract service, educational, or

personal research purposes; however, republication of any portion requires the written permission of the

authors as well as appropriate acknowledgment of this publication.

This report may be cited as:

Fegley B. Jr. and Wanke H., eds. (1992) Workshop on Innovative Instrumentation for the In Situ Study

of Atmosphere-Surface Interactions on Mars. LPI Tech. Rpt. 92-07, Part 2, Lunar and Planetary

Institute, Houston. I0 pp.

This report is distributed by:

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LPI Technical Report 92-07o Part 2 ul

Program

Thursday, October 8, 1992

Morning Session

09:15 Welcome by H. W_ulke

Chair: R. E. Arvidson

09:30

10:00

11:00

11:30

Fegley B. Jr.*

An Overview of Important Scientific Questions about Atmosphere-Surface Interactions

on Mars

Barlow N. G.*

Database of Proposed Payloads and Instruments for SEI Missions

Martin T. Z.*

Atmospheric Imaging from Mars Izmded Stations

Arvidson R.E.* Shepard M.K. Rivard B.

The Potential Utility of Spectral Reflectance and Emission Observations to

Martian Landers

Afternoon Session

Chair: L. M. Mukhin

14:00

14:30

15:00

Treiman A. H.*

Optical Luminescence Spectroscopy as a Probe of the Surface Mineralogy of Mars

Lindner B. L.*

Does UV Instrumentation Effectively Measure Ozone Abundance?

Grant J.A.* Schultz P. H.

Ground Penetrating Radar as a Tool for Investigating Near-Surface Stratigraphy on Mars

* Denotes speaker
iv Workshop on Inno_a_ Inslrumentation

16:00

16:30

17:00

Muhleman D. O.* Janssen M.A. Clancy R. T. Frerking M. Gulkis S. McCleese D. J.

Zurek R. Haberle R. M.

TemperaturePressure and Water Vapor Sounding with Microwm, e Spectroscopy

Mukhin L.M.* Huth J. W_dce H. Dikov Y. Koscheev A. P.

Preliminary Experimental Results of UV Irradiation of Carbonates

Koscheev A.P.* Mukhin L. M.

Mass Spectrometric Studies of Interaction of Martian Atmosphere Gas Components with

Ferric Oxide Surface Under UV-1llumination

Friday, October 9, 1992

Morning Session

Chair: K. Mauersberger

09:00 Mancinelli R. L.* White M. R.

In Situ Identification of the Martian Surface Material and lts Interaction with the Martian

Atmosphere Using D TA/GC

09:30 Mauersberger K.* Mahat_ P. Niemann H.

Mass Spectrometer-Pyrolysis Experiment for A tmospheric and Soil Sample Analysis on the

Surface of Mars

10:00 Gooding J. L. Ming D.W.* Allton J.H. Byers T.B. Dunn R.P. Gibbons F. L.

Pate D.B. Polette T. M.

Determination of Martian Soil Mineralogy and Water Content Using the Thermal Analyzer

for Planetary Soils (TAPS)

11:00 Wright I.P.* Grady M.M. Pillinger C. T.

Determination of Stable Isotopic Compositions of H, C, N, O, and S at the Martian Surface

Using Mass Spectrometry and Stepped CombustionPyrolysis

11:30 Gerasimov M. V.*

A Possible Use of Semiconductor Gas Sensor Instrument for Investigation of

UV-Decomposition of Martian Salts and Release of CL- and S-Containing

Gases to the Atmosphere
LPI Technical Report 92-07, Part 2 v

Afternoon Session

Chair: L P. Wright

14:00

14:30

15:00

16:00

16:30

17:00

17:30

KlingelhOfer G.* Foh J. Held P. Jager H. Teucher R. Kankeleit E.

Development of a MOssbauer Backscattering Spectrometer, Including X-Ray Fluorescence

Spectroscopy, for the In Situ Mineralogical Analysis of the Mars Surface

Agresti D. G.* Morris R.V. Wills E.L. Sheller T. D. Pimped M. M.

Shen M.-H. Nguyen T.

A Backscatter M_ssbauer Spectrometer (BaMS) for Use on Mars

Vistisen L.* Knudsen J. M.

MOssbauer Spectroscopy on Mars. What to Expect?

Knudsen J.M.* Vistisen L.

Magnetic Phases on the Martian Surface

Jakes P.*

Analogue of Hand-HeM Lens and Optical Microscope for Martian In Situ Studies

Fegley B. Jr.*

COMPAS: Compositional Mineralogy Photoacoustic Spectrometer

Rieder R.

Alpha-Particle Backscatter Spectrometry for Elemental Analyses of the Martian Surface

LPI Technical Report 92-07, Part 2 vii

Contents

Workshop Summary ................................................................................................................................ 1

List of Workshop Participants ................................................................................................................. 9

LPI Technical Report 92-07, Part 2 1

Workshop Summary

J. A. Grant and A. H. Treiman

The speakers in the first session of the workshop addressed some of the continuing enigmas regarding the

atmospheric composition, surface composition, and atmosphere-surface interactions on Mars; provided a

description of a database of proposed payloads and instruments for SEI missions that is scheduled to be

accessible in 1993; discussed potential uses of atmospheric imaging from landed stations on Mars; and

advocated the collection and employment of high-spectral-resolution reflectance and emission data.

H. Wanke opened the workshop by stating his interest in constraining the role of sulphur and water in

interactions between atmosphere and surface processes on Mars. He noted that the composition of SNC

meteorites indirectly suggests that some episodes of martian volcanic activity would produce large volumes of SO 2, but limited CO 2. Understanding how this inferred activity relates to the origin of sulphur at

the Viking Landers was cited as an important unresolved question. In addition, surface water probably

plays an important role in weathering, but actual volume and occurrence of this water requires further

constraint.

Other important, unresolved issues of atmospheric composition, surface composition, and atmospheresurface interactions on Mars exist, which B. Fegley Jr. outlined in his presentation. Regarding atmospheric composition, Fegley stated that spatial and temporal variations in both tropospheric water vapor

content and photochemically derived ozone require further in situ definition. Also, the behavior of major

and trace gases in the planetary boundary layer and the abundance of other photochemically produced

gases (e.g., 1-/202, NO, and NO2) is not completely understood. Finally, constraints on the isotopic composition of atmospheric gases would allow measurement of short- and long-term exchanges between

surface and atmospheric inventories. Unresolved issues relating to surface composition include knowledge of both elemental abundances and the isotopic composition ofvolatiles and rocks. The mineralogical

composition of the surface and the distribution of any carbonates or volatile-bearing phases also requires

definition.

How these issues affect chemical weathering at the surface remains incompletely understood. For example, what are the compositions of weathered materials and how has the spatial distribution of weathered

phases changed with time? Are carbonates produced? Can their occurrence be masked? How important is

surface weathering due to UV photochemical reactions? How are iron phases chemically weathered? Can

weathering mask the signature of various rock types? What are the details of the martian water cycle and

how have they changed through time? Weathering products need to be constrained to accurately define

what pristine materials are being weathered and how the atmosphere is affected by weathering. Fegley

summarized by stating that subsequent presentations would describe instruments that should help to resolve many of the issues outlined.

N. G. Barlow provided context for the meeting through description of a database of proposed payloads

and instruments for SEI missions. The database is in hard-copy and payload matrix format and is being

compiled by the Exploration Programs Office at JSC. The name and any updates on an instrument for
2 Workshop on Inm>eal_ve lns_menta_on

either a human and robotic mission are followed by a description that includes anticipated power, data

rate, and mass requirements. Next, data management strategies are described and operational constraints

are cited. Required crew interactions are listed along with payload delivery options and the estimated setup time. Subsequent sections focus on maintenance needs, technology needs, infi'astructure interfaces,

possible resupply needs, and the contact person for the instrument. The payload matrix is an Excel chart

broken into similar sections containing more detail. Barlow stated a desire to include instruments proposed in the current meeting and instructed participants to contact her at the LPI with any updates. She

concluded by indicating the information should become accessible in 1993.

Atmospheric imaging from landed stations on Mars may be a means of addressing a variety of topics according to T. Z. Martin. He began by noting that future surface imaging systems may be driven by requirements to identify mineralogy, but that these cameras could be designed to allow atmospheric monitoting also. When properly located, a landed imaging system could better define typical atmospheric

opacities due to suspended dust and ice and help constrain processes of dust entrainment. Moreover, such

a system could monitor conditions during fog formation/dissipation and/or directly measure the characteristics of suspended dust. Observations of the solar aureole would constrain atmospheric particle scattering, and day/night imaging (e.g., track Phobos) allows measurement of atmospheric water vapor.

Possibilities for identifying the physical properties of aerosols, tracking clouds, and monitoring the formarion/dissipation of the polar hood were also emphasized. Ideally, the imaging system would possess

all-sky capability, obtain phase angles up to 180 °, and be Sun pointing. Ability to image at a range of visible wavelengths is also important and a system triggered by wind speed or humidity would detect transient phenomena.

R. E. Arvidson explained how knowledge of the surface composition of Mars might be increased through

future collection of high-spectral-resolution reflectance and emission data. He first reviewed data from

the Viking Landers that revealed a complex surface whose character ranged from exposures of fresh

blocks and bedrock to surfaces covered by sediment and patinas. Based on the limited spectral resolution

&the Lander images, most rock surfaces appear comparable to terrestrial basalts with thin coatings of

palagonite or desert varnish, although higher-spectral-resolution data is required to confirm such interpretations. Viking Orbiter data allow definition of regional surface units and suggests that the Landers are

located in especially blocky areas; however, it is unclear whether these units reflect variations in surface

composition, character, and/or atmospheric effects on the data. Examination ofmultispectral data (e.g.,

TIMS, AVIRIS) from terrestrial surfaces demonstrates that rock coatings (<<60 lam thick) and/or

weathering finds do not mask compositional information. Moreover, the terrestrial data indicate that a

system capable of collecting high-spectral-resolution data in both the visible and infrared should discern

mineralogy in bedrock outcrops and exposed blocks on Mars. Arvidson also commented that this type of

imaging system would complement a sampling program.

The presenters in the second session discussed the use of optical luminescence spectroscopy to probe

martian surface mineralogy; expressed reservations regarding the ability of UV spectrometers to measure

ozone abundance on Mars; proposed the use of a rover-deployed ground-penetrating radar to locally define near-surface stratigraphy on Mars; suggested the use of microwave spectroscopy to conduct temperatureJpressure and water vapor sounding in the martian atmosphere; presented the results of UV irradiation of carbonates; and described mass spectrometric studies of the interactions between martian atmosphere gas components and ferric oxide surfaces under UV illumination.
LPI Technlcal Report 92-07. Part 2 3

The use of optical luminescence spectroscopy (OpL) as an active probe of martian surface mineralogy

was proposed by A. H. Treiman. OpL uses light to stimulate atoms into an excited state and then records

the photons given off as the atoms return to their ground state. Some elements (e.g., REE) react quickly

to stimulation and produce relatively sharp absorption and emission peaks while others react at timescales

longer than 10 -2 s. Heating the slower-reacting elements causes thermoluminescence as energy stored in

the crystal lattice to be released. On Mars, the inferred presence of luminescent minerals (e.g., carbonates), cold conditions, and cosmic ray exposure at the surface indicate the characteristic spectra produced

by both types of elements can define composition. Effectiveness may be limited, however, if minerals

incorporate significant ferric iron. OpL spectra would be taken at fight when a visible-near-IR

spectrometer would be idle and would ideally utilize a high-power solid-medium UV laser (under development). A UV laser would provide intense tunable light capable of targeting objects at variable range

and serve multiple purposes (e.g., ranging). Alternatively, electron flux could generate optical luminescence (cathodoluminescence), but would require high power and transport of samples to the spectrometer. Finally, samples could be transported to a heating chamber (e.g., TAPS calorimeter) and made to

thermoluminesce.

The ability of UV spectrometers to effectively measure ozone abundance on Mars is not certain. B. L.

Lindner raised questions based on modeling results showing that scattering by dust and clouds in the

atmosphere can mask true ozone concentrations. Ozone should be abundant near the surface; however,

scattering by the entire atmospheric column of dust and clouds makes detection there difficult. Because

the scattering properties of dust and clouds are not well known, current estimates of ozone may be low.

For example, Lindner found that scattering by dust and clouds with optical depths of 0.3 and 1.0,

respectively, results in a 3 × underestimate of ozone. Large solar zenith angles during high-latitude winters

create even greater atmospheric path lengths that may account for inferred low ozone at the poles. As a

benchmark of photochemical models of Mars an accurate knowledge of ozone abundances becomes

important, but may not yet be possible using UV reflectance spectroscopy.

A rover-deployed ground-penetrating radar (GPR) might be used to locally define near-surface stratigraphy on Mars. J. A. Grant described GPR as a proven and relatively inexpensive instrument that uses dielectric contrasts in the subsurface to define stratigraphy and structure at a resolution of tens of centimeters horizontally, and vertically to depths of-40 m. When used around terrestrial impact craters GPR

identifies differing ejecta compositions, alluvium, calcic soils, faults, fractures, and bedrock. On Mars,

GPR data would identify locations where ground truth would be maximized and could be extended over a

broader area, thereby providing context for interpreting results of surface analyses by other instruments.

A GPR could help resolve the origin of sulphates at the Viking Lander sites, identify buried ground ice or

brines, and reveal stratigraphy in the polar layered terrains. Preliminary estimates of GPR dimensions are

-2000 cm 3, -2 kg, and it would use -10 W.

D. O. Muhleman discussed temperature/pressure and water vapor sounding in the martian atmosphere

using microwave spectroscopy. Sounding could be accomplished fi'om either the surface or an orbiting

platform and would take advantage of intense atmospheric spectral lines for H20 and CO. Vertical

resolution of temperature/pressure and water vapor profiles from surface sounding would be --0.25 km up

to 1 km and decrease at higher altitudes. Resultant water vapor and temperature predictions should be

accurate to within 1 lam and 1-2 K respectively. The instrument would have a mass of-2 kg and require

~5 W. Sounding from orbit allows the entire atmosphere to be mapped every few hours at accuracies
4 Wor_hop on Innovaffve fnsrrumenralion

comparable to surface sounded profiles, but with less vertical resolution. The orbiting sounder is less than

-8 kg and requires -15 W. The wavelength of the microwave system ensures that atmospheric dust and

clouds will have no effect on either mode of data collection and profiles could be generated any time.

The results of UV irradiation of carbonates were reported by L. M. Mukhin, who began by noting that

photochemical processes on Mars may contribute to the chemical evolution of the surface and atmosphere and that the surface of the planet is subjected to UV irradiation. Therefore, a calcite monocrystal

was UV irradiated as a first step toward understanding mineral stability under these conditions.

Quantitative data collected during the experiments recorded the evolution of CO 2, possibly due to photodestruction of calcite. This effect does not appear to be related to heating of the sample, however, irradiation of additional samples is necessary to constrain how variable particle size or composition affects

CO 2 release. Results imply that attempts to accurately measure carbonates on Mars may be complicated

by competition between carbonate formation and photodestruction.

A. P. Koscheev presented the results of his work with L. M. Mukhin using mass spectrometry to study

interactions between martian atmosphere gas components and ferric oxide surfaces under UV illumination. Mass spectrometry and thermodesorption spectroscopy methods were used to investigate the effects

of UV stimulation ofFe203 powder in the presence of CO, CO2, H20, and 02. Samples were subjected

to dark conditions and UV irradiation at temperatures 0f200-300 K and pressures between 10-I-10 -2

Ton,. Under dark conditions gases were chemisorbed, which were then released upon heating and UV

irradiation. Adsorbed H20 leads to the appearance of tightly bound CO 2 whose abundance increased with

increasing irradiation. Finally, experiments revealed that adsorbed CO was only released as CO 2.

Koscheev stressed that their work is preliminary and that only one experimental method was used.

Additional species may also be detected during future experiments.

Talks in the third session emphasized in situ analyses of volatile components in martian regolith by

thermal methods: heating the regolith and analyzing the gases that are released. Many different thermal

analyses schemes are available, and there was much discussion about which are most appropriate for

lander-based measurements on Mars. Ideally, these methods will provide analyses of the volatile content

of the martian regolith, and semiquantitative data on the mineral phases in which the volatiles reside.

Some methods would also provide isotope analyses for C, O, and S, which would be important for understanding atmosphere-surface chemical interactions. However, complex materials may yield poorly

interpretable patterns of thermal effects and gas releases. In addition, samples with different grain size

distributions may have distinctly different patterns of thermal effects and gas releases. The gas-analytical

systems in these instruments could be shared among other experiments, including atmosphere analysis and

soil reactivity. The heating systems could be shared with other experiments, such as thermoluminescence

spectroscopy.

The principles of thermal analysis and a description of a differential thermal analysis-gas chromatography

(DTA-GC) instrument were the subject of R, L. MancineUi's presentation. In DTA, a sample and a standard are continuously heated, and the temperature difference between them records absorption or release

of heat by the sample. The proposed instrument could heat samples to 1200°C. Released gases would be

analyzed by GC, in which the gases are separated by how strongly they are adsorbed onto selected substrates. GC can provide good quantitative analyses of gas species, but is insensitive to isotopic abun-
LPI Twchnical Report 92-07, Part 2 5

dances. This DTA/GC analyzer is at a high level of technical development, as the DTA is listed for both

MESUR and Mars'96, and the GC is similar to that developed for CRAF.

K. Mauersberger described a multisample thermal and gas analysis system using pyrolysis and mass spectrometry (MS). This instrument would heat regolith samples in temperature steps and analyze the evolved

gas at each step for bulk and isotopic composition. Regolith samples would be fed into sapphire cells on a

turntable (six to eight cells), which would then be rotated to bring a given sample to a heating chamber.

Stepped heating to 1000°C would be accomplished by conventional means. The evolved gases would be

fed into a quadrupole field mass spectrometer (QMS) and analyzed. An active vacuum pump would be

important if more than a few samples were to be analyzed. Instruments in this system have a long spaceflight heritage including the Viking CGMS experiment. The proposed system would permit analyses of

elemental and isotopic abundances ofvolatiles in many samples, but could not evaluate heat effects during

heating, nor temperature profiles of gas precise releases. With an ion-getter vacuum pump, and configured for a analysis of a single sample, this instrument would weigh 4 kg; with a turbomolecular vacuum

pump (under development), and configured for multiple samples, this system would weigh 5.5 kg.

The TAPS instrument (Thermal Analyzer for Planetary Soils) is currently under development and was

described by D. W. Ming. TAPS uses differential scanning calorimetry (DSC) to measure heat effects,

and a solid-state sensor for analysis of evolved water. In DSC, a sample and standard are heated independently so that they stay at the same temperature; heat effects are thus measured directly. In the TAPS

instrument, a regolith sample would be heated continuously to 1000°C. Effluent gas from DSC would

pass over a solid-state water sensor (capacitative-polymer type); other solid-state sensors could be accommodated. Instruments similar to TAPS have been designed for space missions, but never flown. In

the present design, TAPS would weigh 1.5 kg, and draw 5 W maximum. TAPS would provide quantitative estimates of abundances of volatile-bearing minerals in the regolith, in addition to mineral identification and volatile inventory. TAPS includes its own sample collection system, but must be emplaced onto

the regolith to perform analyses.

At this point, Dr. S. Linkin of the Babukin Center, Russia, gave a short description of the Mars '94-'96

spacecraft and their status with respect to technical and political issues.

Next, Ian Wright presented a paper describing a conceptual scheme for high-precision isotope measurements of light elements (C, H, O, N, and S) from volatiles and silicates. The isotope measurement would

be of a quality comparable to that obtained routinely on Earth, notably in obtaining abundance ratios for

the three oxygen isotopes. The proposed scheme would start with stepped combustion and/or pyrolysis of

a regolith sample; oxygen for combustion could be provided by a solid reagent. Evolved gases would then

be chemically separated so that a single species would be measured at a time; separation could be effected

by gas chromatography, cryogenic cooling, or chemical reactions. Separated gases would flow into a

high-precision neutral gas mass spectrometer, which would have been calibrated against a reference gas.

Stepped fluoridation reactions would permit measurement of oxygen isotopes in silicates and sulfur

isotopes on sulfides. The proposed instrumentation derives fi'om that used routinely on Earth; similar

mass spectrometry systems have been flown in space and the pyrolysis/combustion system could follow

the previous designs. The gas separation and chemical reactivity steps are at the conceptual development

stages.
6 Workshop on.fnnovat_ Instrumentation

The final talk of the session was by M. V. Gerasimov on the photochemical devolatilization of chlorides

and sulfates and the use of solid-state sensors to analyze gas compositions. First, data was presented

showing that chloride and sulfate minerals may decompose under the direct action of short-wave ultraviolet (UV) fight, such as hits the surface of Mars. The compositions of evolved gases in the Mars atmosphere can be measured using an array of semiconductor (metal-oxide) resistivity films. The electrical resistance of each film sensor is strongly affected by gases adsorbed fi'om the ambient atmosphere; different

films are sensitive to different gases. Concentrations of 02, CO, H20, and H 2 are readily determined;

concentrations of S, C1, and 03 may also be measurable. The observation of photochemical volatilization

was new to most participants, and elicited much discussion. The gas sensor array has been demonstrated

in the lab, but has not been developed or flown on spacecraft. The array would require only 50 mW

power, could be used in chemical analysis instruments, and requires a resistance meter with a large dynamic range (103-107 ohms).

The first half of the last session dealt with investigations of magnetic properties of the martian surface.

Three talks described M6ssbauer spectrometers and spectroscopy as probes of the magnetic and ironbearing mineralogy of the surface. There was general consensus a M6ssbauer spectrometer would be an

important instrument for in situ analyses of Mars' surface. The final portion of the workshop was reserved for instruments or concepts that were outside the other focused sessions. The talks were on optical "hand-lens-scale" microscopy, photoacoustic optical spectrometry, and alpha-particle backscatter instrumentation.

G. KlingelhOfer described the physics of MOssbauer spectroscopy and a spectrometer design under development for the Mars'96, Marsnet, and MESUR. missions. M6ssbauer spectroscopy operates by detecting

energies at which nuclear gamma rays are absorbed by an iron isotope, and relating the shiPts to electric

and magnetic field strengths at an iron atom's nucleus. M6ssbauer spectroscopy permits direct identification of Fe-bearing minerals, if present in sufficient quantity and in relatively simple mixtures, and

semiquantitative determination of mineral proportions. Most MOssbauer spectroscopy on Earth is done in

transmission mode, but backscatter mode permits natural sample geometries.

The workshop was shown a working prototype backscatter M6ssbauer spectrometer, representing a high

level of technical development. The instrument and its electronic controls are about the size of a soda can

(700 cm3), weigh less than 400 g, and consume less than 1.5 W during operation. The instrument may be

modified to permit analyses of chemical compositions by the X-ray fluorescence (XRF) technique,

pending development of solid-state ambient temperature X-ray detectors with improved energy

resolutions.

The following talk, by D. G. Agresti, described his group's development of a backscatter M6ssbauer

spectrometer suitable for MESUIL lunar (Artemis), and other planetary studies. This instrument and that

of Klingelh6fer and others are quite similar, representing a convergence of design solutions. As with the

above design, backscatter M6ssbauer spectrometers may also provide some information on compositional

changes with depth into the sample. The instrument, presented as a working prototype, is projected to a

final mass of less than 500 g, volume of less than 300 cm 3, and power consumption less than 2 W.

L. Vistisen discussed interpretations of backscatter M6ssbauer spectroscopy of model analogues to martian surface materials. It was shown that backscatter M6ssbauer spectra such as could be acquired on
LPI Technical Report 92-OT, Part 2 7

Mars would permit mineral identifications to almost the same accuracy as is possible on Earth with

transmission M6ssbauer spectra. A spacecraft-borne backscatter M6ssbauer spectrometer could successfully resolve and identify at least three Fe-bearing minerals (olivine, titanomagnetite, and ilmenite) in a

natural basalt matrix, and could identify macrophase hematite and other ferric oxides in a regolith.

The final talk on magnetic experiments was by J. M. Knudsen, who talked about the identification of

magnetic minerals in the martian soil by magnetic separation. R was proposed that a martian lander

should carry a series of five to eight small permanent magnets, weaker than those on the Viking landers,

to permit grain separations according to their saturation magnetizations. With an additional heat source,

grains adhering to the magnets could be heated so as to measure their Curie temperatures. This scheme

could yield mineral separates, which could then be analyzed by other methods. The five-magnet experiment would be extremely cheap and light (< 100 g) and would consume no power. It would require, however, both a manipulator arm and a visible-near-IR imaging system. The heating/separation scheme would

require both power and additional mass, which were not detailed.

The final half-session of the workshop was devoted to singular presentations. First, P. Jakes reminded the

attendees about the value of low-magnification (-10×) visible imagery for rock and mineral identification,

and proposed a "hand-lens" for planetary surface investigations. Terrestrial studies of rocks, sediment or

regolith use -10× magnification imagery from the beginning because (1) many mineral grains and structures in geological materials are resolved at that scale and (2) the human eye and brain are superb at pattern recognition. Jakes presented a video of a prototype instrument consisting of a fixed-focus optical

system, self-contained illumination, and a CCD camera. The instrument is designed to be placed on the

object of interest, and provides images that are readily interpretable as to grain sizes, shapes, and colors.

The whole instrument would probably weigh less than 100 g and have a volume of less than 100 cm 3.

B. Fegley Jr. described work performed by W. H. Smith on photoacoustic spectroscopy as a method for

obtaining visible--near-IR absorption spectra in situ. Photoacoustic spectroscopy operates by illuminating

the unknown with an amplitude-modulated beam of monochromatic light, and scanning the wavelength of

the light. When incident light is absorbed, the unknown sample will expand and contract in phase with the

amplitude modulation, yielding sound that is detected by the sensor. Thus, photoacoustic spectroscopy

can yield a direct visible-IR absorption spectrum on an unprepared, opaque sample. Instrumentation is

under development that is aiming for volume < 125 cm 3, mass < 110 g, and power consumption of<1.5

W. Spectra will be measured over at least 0.7-2.5-1am wavelength, with extensions to shorter and longer

(thermal IR wavelengths).

Finally, R. Rieder discussed alpha-particle backscatter spectrometry (also called Rutherford Backscatter)

and PIXE (proton-induced X-ray emission) spectrometry for probes of planetary surfaces, Instruments of

these types have been used since the Surveyor lunar missions; more recently they have flown on Phobos

and are scheduled to fly with the Mars'94 and Mars'96 missions. Both methods together allow bulk

chemical analyses of rock or regolith surfaces; alpha backscatter is sensitive to light elements (C, O),

while PIXE is more sensitive to heavier elements (Na to Fe and heavier). In operation, a source of alpha

particles is brought near the sample, and re-emission from the sample is measured as a function of particlephoton energy and emission angle. For PIXE, protons are produced within the sample as elemental

nuclei react with the incident alpha particles.

PRECEDING P_GE BLANK NO] FILMED

LPI Technical Report 92-07, Part 2 9

List of Workshop Participants

David G. Agresti

Department of Physics

University of Aiabama

Birmingham AL 35294-1170

Raymond E. Arvidson

Depamnent of Earth and Planetary Sciences

Washington University

St. Louis A40 63021

Nadine G. Barlow

Mail Code XI

SYSCOM

NASA Johnson Space Center

Houston TX 77058

Vitalii Bondarev

Space Research Institute

Russian Academy of Sciences

ul. Porfsoyuznaya 84/32

Moscow 117810

RUSSIA

William Boynton

Department of Space Sciences

University of Arizona

Tucson AZ 85721

Johannes BrQckner

Max-Planck-lnstitut far Chemie

Saarstrasse 23

6500 Mainz

GERMANY

Guermadi Dolnikov

Space Research Institute

Russian Academy of Sciences

ul. Porfsoyuznaya 84/32

Moscow 117810

RUSSIA

Gerlind Dreibus

Max-Planck-Institut far Chemie

Soarstrasse 23

6500 Maim

GERMANY

Evgenii Evlanov

Space Research Institut

Russian Academy of Sciences

ul. Porfs_ 84/32

Moscow 117810

RUSSIA

Utz Fabian

Max-Planck-Insfftut far Chemie

Saarstrasse 23

6500 Mainz

GERMANY

Bruce Fegley

Department of Earth and Planetary Sciences

Washington University

St. Louis MO 63130-4899

Michael V. Gerasimov

Space Research Institute

Russian Academy of Sciences

ui. Porfsoyuenaya 84/32

Moscow 117810

RUSSIA

John A. Grant

Department of Geological Sciences

Box 1846

Brown University

Providence RI 02912

Petr Jakes

Faculty of Science

Department of Economic Geology

Albertov 6

Praha 2

12843 Czechoslovala'a

E. Kankeleit

Technische Hochschule Darmstadt

Institut fl_r Kernphysik

Schlossgartenstrasse 9

6100 Darmstadt

GERMANY

G. Klingelh6 fer

Technische Hochschule Darmstadt

Institut f_r Kernphysik

Schiossgartenstrasse 9

6100 Darmstadt

GERMANY

Jens Martin Knudsen

H. C. Orsted Institute

Universitetsparken 5

2100 Copenhagen

DENMARK
lO Workshop on Innovativ_ Instrumentation

Alexander P. Koscheev

Karpov Institute of Physical Chemistry

ul. Obukha 10

103064 Moscow E-64

RUSSIA

Vladimir Khromov

Space Research Institute

Russian Academy of Sciences

ul. Porfs_ 84/32

Moscow 117810

R USSM

Bernhard Lee Lindner

AER

840 Memorial Drive

Cambridge MA 02139

Slava Linkin

Space Research Insfftute

Russian Academy of Sciences

ul. Porfsoyuznaya 84/32

Moscow 117810

RUSSIA

Rocco L. Mancinelli

Mail Stop 239-12

NASA Ames Research Center

Moffeff Field CA 94035-1000

Terry Z. _

Mail Stop 169-23 7

Jet Propulsion Laboratory

4800 Oak Grove Drive

Pasadena CA 91109

Konrad Mauersberger

School of Physics and Astronomy

Universi_ of Minnesota

I 16 Church Street SE

Minneapolis MTV .$5455

Doug Min 8

Mail Code SN4

NASA Johnson Space Center

Houston TX 77058

Duane O. Mutdemma

California Insti_te of Technology

Pasadena CA 91125

Lev M. Mukhin

Embas_ of the Russian Federation

1125 16th Street NW

Washington DC

Nikolai Porslmev

Space Research Institute

Russian Academy of Sciences

uL Porfsoyuamaya 84/32

Moscow 117810

RUSSIA

Rudolf Reider

Max-Planck-Institut f_r Chemie

Saarstrasse 23

6500 Mainz

GERMANY

H° Rosenbauer

Max-Planck-lnstitut far Aeronomie

Max-Planck-Strasse 2

Pos_ach 20

3411 Katlenburg-Lindau/Harz

GERMANY

Allan H. Treiman

Mail Code SN4

NASA Johnson Space Center

Houston TX 77058

Claude d'Uston

CESR

9 Avenue du Colonel Roche

BP 4346

31029 Toulouse cedex

FRANCE

V, Vanzani

Dipartimento di Fisica

Universita di Padova

Via Marzolo 8

35131 Padova

ITALY

Lise Vistiscn

Niels Bohr Institute

Biegdamsvej 17

21 O0 Copenhagen

DENMARK

Heinrich W/lnke

Max-Planck-lnstitut fitr Chemie

Saarstrasse 23

6500 Mainz

GERMAN]'

Ian Wright

Department of Earth Sciences

Open UniverMty

Walton Hall

Milton Keynes MK7 6AA

ENGLAND