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MARS Electromagnetic Sounding Experiment




Part 1
Scientific and Technical Plan


A proposal for the construction, installation and
operation of a MARSES sounding on the Mars - 2003-2005 Mission:
comparative investigation martian and earth cryolitozone
(possible investigation of subsurface relics of martian life)
and for interpretation of data.

Front Cover
"Islands" near Chryse Planitia. Teardrop-shaped "islands" are shown at the
mouth of Ares Vallis near the southern boundary of Chryse Planitia. Flow
was from the south and apparently diverged around obstacles such as craters
and low hills to form a sharp prow upstream and elongate tail downstream. A
shallow moat surrounds the entire island. Similar patterns on Earth have
been formed by catastrophic floods, wind erosion. and glacial action. From
top to bottom, the three large craters are named Lod, Bok, and Gold. [211-
4987; 21? N, 31? W] (Courtesy of NASA)



Principal Investigators:

( ( (
Yu.R.Ozorovich Stichting"InterECOS"/IKI,NL/RU(7-095-333-3177(7-095-333-
2177(yozorovi@mx.iki.rssi.ru
Experiment Manager:

( ( (
B.Zubkov IKI, RU
Co-Investigators:
V.Linkin IKI , Russia ({7}-095-333-2177 ({7}-095-333-2177 (
gotlib@iki.rssi.ru
V.Gotlib IKI, Russia ({7}-095-333-2177 ({7}-095-333-2177 (
gotlib@iki.rssi.ru
R.Rider MPIC, Germany ({49}-5556-979-439 ({49}-5556-979-149 (
@
Y. Barbin CNRS/SA, France ({33}-164-474-295 ({33}-169-202-999 (
yves.barbin@aerov.jussieu.fr
A.Ocampo JPL, USA ( (
( @
W.Smith JPL,USA
Pascal Lee, NASA Ames,USA
F.Fanale Un. Hawaii , USA ((808) 956-3149( (808) 956-
6322(fanale@kahana.pgd.hawaii.edu
R.O.Kuzmin Vernadsky Inst., RU
V. Andrianov IRE/RAS, RU
S.M.Clifford LPI,USA
R.Grard ESA/SSD, The Netherlands
S.Squyres Cornel U.,USA


Institute Addresses:

GEOPHEX 605 Mercuryy Street,Raleigh,NC 27603-2343
Stichting "InterECOS" Witmakerstraat 10, 6211 JB Maastricht,NL
CEPHAG B.P. 46, F-38402 St. Martin d'Heres, Grenoble
CNRS/SA B.P. 3, F-91371 Verrieres-le-Buisson Cedex, France
Cornell U., Center f. Radiophys. and Space Res., 424 Space Sci. Bldg.
Ithaca, NY 14853-6801, U.S.A.
DESPA CNRS, Observatoire de Paris, 92195 Meudon Cedex, France
DLR Weïling, Postfach 1116, D-82230 Oberpfaffenhofen, Germany
ESA/SSD Postbus 299, NL-2201 AG Noordwijk, The Netherlands
FMI P.O. Box 503, FIN-00101 Helsinki, Finnland
HUT Lab. of Space Techn., P.O. Box 3000, FIN-02015 HUT, Finland
IKI/RAS Profsouznaya ul. 84/32, 117810 Moscow, Russia
IRE/RAS Mokhovaya St. 11, 103907 Moscow, Russia
LPCE 3A, Ave de la Rech. Scient., F-45071 Orlùans Cedex 2, France
LPI Center f. Adv. Space Studies, 3600 Bay Area Blvd., Houston, Texas
77058, U.S.A.
MPAe Max-Planck-Str. 2, D-37191 Lindau/Harz, Germany
NDRE P.O. Box 25, N-2007 Kjeller, Norway
RST Galserwaldstr. 14, CH-9015 St. Gallen, Switzerland
U. K?ln Inst. f. Geophys. u. Meteor., Albertus-Magnus-Platz, D-50923 K?ln,
Germany
U. Leicester Dept. of Phys. and Astron., University Rd., Leicester LE1
7RH, U.K.
U. M?nster Inst. f. Planet., Wilhelm-Klemm-Str. 10, D-48149 M?nster,
Germany
U. Paris-Sud, LGDTP, Bòt. 504, U. Paris-Sud, F-91405 Orsay Cedex, France
Vernadsky Inst. Kosygin St. 19, 117975 Moscow GSP-1, Russia


Executive Summary
MARSES
MARS E/M Sounnding Experiment


Principal Investigators: Yu.Ozorovich (Stichting "InterECOS") NL/RU.
Experiment Manager:
B.Zubkov ( IKI ) RU
.

Co-Investigators:
V. Andrianov (IRE/RAS) RUS
V.Gotlib IKI RUS
V. Barbin (CNRS/SA) F
S.M. Clifford (LPI) USA
F.Fanale Uni. of Hawaii USA
R. O. Kuzmin (Vernadsky Inst) RUS
R.Rider MPICh D
V.M. Linkin (IKI/RAS) RUS
Y.Barbin CNRS/SA France
W.Smith JPL USA
A.Ocampo JPL USA
Yu.Bar-Cohen JPL USA
R.Grard ESA/SSD The Netherlands
S.Squyres Cornel U., USA
Associated scientists:


MARSES (GEM-2,3 and MARS TEM Sounding- 48,97) is sounding instruments
designed for the primary task of searching for water, water-ice or
permafrost layers believed to exist at some depth under the visible surface
of Mars. There is much evidence that water once was abundant on Mars.
There are stream lined islands formed by flowing water, flow patterns
reminiscent of wadis in Earth deserts, and outflow channels thought to have
been formed by sudden out-rush of subterranean water. Secondary tasks are
the measurement of the soil properties of the subsurface of Mars which
include porosity, electrical resistance of the liquid phase, thermal
conductivity, temperature dependence.
Estimates of Martian water ranges from a 50 to a 500 m deep planet-
wide ocean. No obvious mechanism for the escape of water from the planet
has been devised. JeanÄs escape of water via the atmosphere is very slow
(of the order of 3 m over 5 Gy). Assuming that Mars was formed with
approximately the same relative amount of water as the Earth, it must be
assumed that a substantial fraction of this water remains on Mars in one
form or another. It is commonly believed to be bound as ice in the polar
caps and, in the ground, as ice, icy permafrost or even as water. There is
also indirect evidence for widespread presence of ice, bearing permafrost
and liquid fase of water through the existence of rampart craters, terrain
softening, chaotic terrain and thermokarst.
In order to ensure the greatest possible penetration of the
electromagnetic waves into the ground the wavelength must be chosen as long
as possible.
A main task of the MARSES system is to examine changes in subsurface
properties of local areas regolith on Mars surface, and to relate them to
optical images and other remout sensing data in order to understand the
nature of different terrain forms.


The responsibility for the development of the MARSES system and for
the coordination of the modifications of the MARSES system and its
operation will rest with MPICh, with key partners in
JPL/NASA , IRE/RAS and IKI/RAS (Russia), CNRS CEPHAG and SA (France) and
ESA/SSD (the Netherlands). A brief summary of the questions addressed by
MARSES and the measurements which must be made in order to answer them is
given in the following table.

|Is there subsurface |Presence of effects the induce |
|ice/permafrost on Mars?|polarization would be evidence of icy |
| |layers. |
|What is the depth of |Determination of thermophysical |
|the layers and the |parameters subsurface. Search for several|
|nature of the layer |frequency components.. |
|transition? | |
|Does the depth vary |MARSES sounding may covers a wide a range|
|with latitude? |of latitudes |
|Do the layers and the |Comparison of properties of MARSES |
|subsurface sounding |sounding with changes in terrain and |
|correlate with visible |radar surface echo properties. |
|and radar surface | |
|features? | |
|What is the porosity |Measurement of the electrical resistivity|
|and temperature profile|subsurface layers . |
|of the subsurface | |
|lay-ers ? | |
| | |


Questions addressed Observations bearing on these question




CONTENTS

Executive Summary iii
Contents v
Acronyms & Abbrevations vii
1.0 Science Objectives 1
1.1 Subsurface Science, Introduction 1
1.1.1 Model of Mars cryolitozone 1
1.1.2 Porosity of the Surface 3
1.1.3 Regolith Temperature 3
1.1.4 On the Stability of the Ice 3
1.1.5 Rampart Crates 4
1.1.6 Terrain Softening 5
1.1.7 Summary of Objectives of the MARSES SubSurface
Observation 5
2.0 Proposed Investigations in Context of Other
Investigation 5
3.0 Technical Description of Instrument 6
3.1 Electrical Properties of the Martian Surface 6
3.2 Physical basis of the method for TEM Sounding 8
3.2.1 The main parameters TEM Device for Mars
Electromagnetic Sounding 8
3.2.2 Conclusion on Frequency Choice 8
3.3 Description of the Instrument 9
3.3.1 Requirement of the Instrument 9
3.3.2 Conceptual Design of the MARSES Instrument 9
3.3.3 MARSES Hardware Overview 9
3.3.3a MARS TEM-48,97 Hardware Overview 9
3.3.8 On Board Data Handling 10
3.3.9 The Date Rate 10
3.3.10 Data processing MARS TEM-48,97 11
3.3.11 Data Transmition to Ground
11
4.0 Data reduction and Scientific Analysis 11
4.3 Interpretation of the Data
11
4.3.1 Detection of Subsurface Discontinuities
11
5.0 Test and Calibration Plans 11
5.1 Testing 11
5.2 The Instrument Calibration and Field Testing
11
6.0 System Level Assemblyy, Integration and
Verification 12
7.0 Flight Operations 12
8.0 Team Qualifications and Experience 12
9.0 Program Managment 12
Reference 13

ANNEX I: The program for field e/m Mars sounding testing 15
ANNEX II: Active-passive microwave remote sensing
of Martian permafrost and subsurface water
15
ANNEX III: MARS TEM-48,97 Instrumentation 16
Acronyms and Abbreviations:

ABL Atmospheric Boundary Layer
A/D Analog to Digital
AIV Assembly, Integration and Verification
CEPHAG Centre d'Etudes des Phùnomønes Alùatoires et de Gùophysique
CNES Centre National d'Ùtudes Spatiales
CNRS Centre National de la Recherche Scientifique
CNRS/SA Centre National de la Recherche Scientifique/Service
d'Aeronomie
CO-I Co-Investigator
CW Continuous Wave
DDS Direct Digital Synthesis
DESPA Departement de Recherche Spatiale
DLR Deutsches Zentrum f?r Luft- und Raumfahrt
DMA Direct Memory Access
EGSE Electrical Ground Support Equipment
EISCAT European Incoherent Incoherent Scatter Association
ELISMA Etude Locale de L'Ionosphere Superieure de Mars
(electromagnetic investigation of Mars)
EM Experiment Manager
EMC Electromagnetic Compatibility
ESA/SSD European Space Agency/Space Science Department
FFT Fast Fourier Transform
FMI Finnish Meteorological Institute
GPS Global Positioning System
GSE Ground Support and test Equipment
HF High Frequency
HRR High Resolution Radar
HUT Helsinki University of Technology
IKI/RAS Space Research Institute/ Russian Academy of Sciences
IRE/RAS Institute of Radio-Engineering and Electronics/Russian
Academy of Sciences
IRFU (Swedish Institute of Space Physics, Uppsala Division)
LFM Linear Frequency Modulation (chirp)
LGDTP Laboratoire de Geologie Dynamique de la Terre et des
Planetes
LPCE Laboratoire de Physique et Chimie de l'Environement
LPI Lunar and Planetary Institute/Centre for Advanced Space Studies
LWR Long Wavelength Radar (on Mars96)
MAS Millimeter Wave Atmospheric Sounder
MDU Mast Deployment Unit
MGS Mars Global Surveyor
MIP Mutual Impedance Probe
MPAe Max-Planck-Institute f?r Aeronomie
NAIC National Astronomy and Ionosphere Center
NDRE Norwegian Defence Research Establishment
PI Principal Investigator
PLL Phase Locked Loop
PRF Pulse Repetition Frequency
PS Principal Scientist
RST Raumfahrt Systemtechnik AG
SC Spacecraft
SNR Signal-to-Noise Ratio
SOUSY Sounding System (MST radar )

1.0 Science Objectives.

1. 1 Subsurface Science, Introduction

Analysis of the ground-based geophysical cryolitozone - related
electromagnetic studies which takes into account characteristics of the
preliminary electrodynamics model of Mars cryolitozone ( this model was
based on the current geological concepts of the cryolitozone structure,
on the estimates of the ice containing material or wet fraction of
subsurface horizons at negative temperatures, on physical-chemical
transitions in the solutions of KCl , NaCl, CaCl2 with the martian
regolith and so on) - all it is shows the potential possibilities of the
Mars electromagnetic sounding in the depth interval up to one kilometer
from the planetary surface or from satellite orbit.
The presence of low conductivity screens in the section structure and bad
grounding conditions should decrease the efficiency of traditional ( or
so called vertical methods of electric sounding, or VES ) contact sounding
methods. But such screen is not a barrier for magnetic field and in these
conditions inductive sounding with controlled source should be more useful.
The usefulness of different methods of inductive sounding ( frequency
modulate or impulse ) in cryolitozone studies will be defined by the
following factors:
- cryolitozone is characterized by the relatively low conductivity of
permafrost soil of weak contrast of geoelectric section;
- the season variations of phase condition of upper and depth's layers of
Mars surface may exit;
- the high and low conductivity screens at the surface and in depth of
permafrost soil may present.
Above mentioned aspects may limit the possibilities of high frequency
sounding (HFS) method for Mars cryolitozone structure studies. The
experience in experimental studies of permafrost clay formation in the
earth's condition similar to Mars permafrost soil shows that the depth
limit of HFS methods is about 50 m.
VIKING experiments showed that Martian soil contains substantial component
of magnetic materials ( about 4%) and therefore Martian surface deposits
are belong to the soil class, completely different from lunar regolith,
which properties are widely used for attention estimates in HFS method.
Chemical composition of Mars subsurface material is characterized by the
following parameters: 40-45% SiO2, 7-7.5% Al2O3, 17-19% Fe2O3, 5-7% MgO , 5-
6% CaO, 0.4-0.7% TiO2, 6-7% SO3, 0.3-0.9% Cl and traces of K.
Chemical analysis formed the base for conclusion that 60-80% of Martian
soil material are the smectic clays mixture with different solvable salts,
such as keyserite ( MgSO4) or sodium chloride
( NaCl ). Iron oxide ( Fe2O3 ), calcytes ( CaCO3) and quarzites ( SiO2)
supposed to be present also.
Martian soils are substantially different by their properties from the pure
surface ices and gletcher ices.Relative magnetic susceptibility of the
Earth soils is close to 1 but Martian soils may have much more larger
values of magnetic susceptibility. Estimates shows that the attention in
this environment may be several orders of magnetitude larger than in ice.

Therefore even in Martian equatorial regions ( from -300 to +300 latitude
) with several hundreds of meters palagonites or montmorillonites layers
HFS method may not bring information about cryolitozone structure up to the
depth of 500 m, that is up to upper border of ice-bearing layer. In the
middle latitude region ( from 300 to 500 ) the depth upper border of
permafrost layer should be equal to 100-150 m and while in high latitudes
it may be at the surface and in this HFS method allows to measure the depth
of permafrost.
The difficulties with the estimation of attention ( that is the sounding
depth) require the comparative studies in the natural earth's conditions
close to conditions on Mars.


1.1.1 Model of Mars cryolitozone.

Mars cryolitozone formation appears to be cyclic process ( defined by
initial atmospheric composition, geological structure of the surface,
astronomical parameters of the planet and so on ) which determined current
cryolitozone structure with heterogeneous character in depth, meridional
and latitude dimensions.
Current condition of Martian atmosphere evolution are characterized by
clearly visible deficit of atmosphere saturation by water vapor in the
latitude region from - 500 to + 500.
This leads to the ice evaporation from surface permafrost layers and to
formation of dry frost soil in this latitude region above the ice
containing soil.
Photogeological analysis of the newly formed impact craters on Mars, which
excavated permafrost layers to the depths from several dozens of meters
to kilometers and form fuidized ejects, is the only method ( indirect ) of
estimation the depth distribution of Mars permafrost which is necessary for
the design of hypothetical electrodynamics model. This analysis shows that
the upper border depth interval for mean model is 150-300 m. These data are
very important for the estimation of necessary depth limit for sounding and
for the determination of dynamic range of depth, where the main changes of
phase conditions of subsurface permafrost may be observed, which have a
influence on the diffusion of water vapor into boundary layer of
atmosphere.
Let's suppose on the base of the photogeological analysis of
electrodynamics properties of permafrost and the possible phase conditions
of subsurface Martian soil layers the following cryolitozone structure for
calculation model:

1 st layer - dry frozen soil
( = 104 Om x m
2 nd layer - transition layer defined by (
= 10 - 103 Om x m
diurnal or seasonal temperature
wave
3 rd layer - permafrost
( = 103 Om x m

4th layer - salt solution with negative (
= 10 Om x m .
temperatures


Various data allow to estimate that the dry layer of frozen Mars soil may
be formed during in 3.5 billion of years period.Therefore the upper border
position of the permafrost layer may be used as specific indicator of Mars
climate evolution. Since the amount of surface moisture and its
distribution character are conditioned by the cryolitozone scale structure
its investigation is considered to be an important aspect of the
forthcoming Martian projects. In order to create Martian climate and
atmosphere circulation models the whole complex of information on surface
provided by optical and infrared observations, regional albedo surface
measurements, ground layer thermal flow investigation, etc must be
carefully studied. To that end the studies of permafrost formation global
distribution and their appearance in h ( 1 m thick layer may prove to be
essential.
The only way to obtain information about Mars's surface mezoscale
structure is to a high spatial resolution panoramic equipment onboard.
Mars' surface radioimages would allow to identify regions differing in ice
percentage content in cryogenic surface structures or in mineralized
solutions of negative temperature and to estimate the relative quantity of
cryogenic formations - permafrost fractions as well as to measure the
soil looseness or porosity degree. In additional it would be possible to
restore various regions' average vertical temperature, humidity and
porosity profiles of less 1 meter thick surface layer.
These dependencies combined with results of depth sounding (0.5 - 1 km)
and magnetotelluric ( 1 - 5 km) sensing would provide new and more
detailed information on Martian crust structure and character and its
cryolitozone necessary to create a more reliable paleoclimatic model of
the planet and possible ( or more probable ) place of the relict martian
life in the past and now.
Instrumentation on the Mariner 9, the Viking 1 and 2 missions, and more
recently on the Mars Pathfinder and the Global Surveyor together with
observations with the Hubble telescope have provided for a quite rich
picture of both the Martian surface and the atmosphere. The images have
shown a relatively dry surface with polar caps of water ice and CO2 ice
which varies with season. There is sample geological evidence that there
has been water flowing over the surface in abundance. The surface is criss-
crossed with wadi-like riverbeds, bearing testimony to past violent water
flows (Carr, 1986; Baker, 1982; Squyres, 1984). Theoretical estimates of
the permafrost thickness range from 3 to 7 km near the poles to between 1
and 3 km near the equator (Fanale et al., 1986). Liquid water should exist
under the ground ice, at least at middle latitudes. The depth to the top of
the ice layer and the transition depth from ground ice to liquid water
appear to have had significant effects on the morphology of surface
features (e.g., outflow channels, rampart craters, terrain softening).

Water may be a prerequisite for life forms in the solar system, at least
for life forms as we know them, and the search for water is a primary task
of MARSES. Hence the interest to establish the presence and properties, or
states, of the water. Life is with certainty only known to exist on our
planet. With so far only one planet, the Earth, available to define the
boundary conditions for life, it is of the greatest interest to research
the conditions on another planet, and then to determine if life is or is
not present there. This would immediately and immensely add to our
understanding and definition of the conditions for the occurrence of life.



1.1.2 Porosity of the Surface
The surface is covered by craters due to meteoroid impact which occurred
over the 4.5 Gy of existence of the planet. It is estimated that the
impact activity has crushed, redistributed and turned over as much as 2 km
of regolith, and has left a material which is porous and with a basement
which if heavily fractured (Fanale, 1976). Based on the experience gained
from seismic investigations on the moon (Binder and Lange, 1980) it is now
assumed that the porosity in the Mars regolith decreases as an exponential
function with depth but with different parameters because of the difference
in gravity and temperature: [pic]
where h is the depth below the surface. Scaling from the lunar experience
the constant K is 2.8 km (Clifford, 1981, 1984). From measurements on the
Viking landers the surface porosity is about 50 % (Clark et al., 1976), and
the self compacting depth is roughly 11 km (depth where porosity has fallen
to 1 %). This would allow a global ocean 1.4 km deep to be hidden in the
pores of the regolith (Clifford, 1984).

1.1.3 Regolith Temperature
The temperature of the interior of the Martian regolith cannot be predicted
with any precision because neither the thermal conductivity nor the
geothermal heat flux is known. It is generally agreed that the upper part
of the Martian regolith remains below the freezing temperature of water of
273 K. Such a region is often referred to as a cryolithosphere (Kuzmin,
1977). Note that we assume solute-free water and that the actual freezing
point could be lower. The mean surface temperature is low enough to keep
the water frozen at the surface at all latitudes. At some depth the
temperature is higher, and the pressure also higher, allowing water to
exist in liquid form. The exact lower boundary of the cryolithosphere is
not known. If measurements can be made of the lower boundary of the
cryolithosphere the depth can have a bearing on the solute content, the
thermal conductivity and on the geothermal flow from the Martian interior.

1.1.4 On the Stability of the Ice
Although the surface temperature is everywhere below the freezing point
of water, Viking Orbiter
Atmospheric Water Detectors indicate a global frost point temperature of
200 K. As a result of this the ground ice can only exist in equilibrium
with the atmosphere at latitudes above 40?. The cryolithosphere near the
equator therefore is desiccated to considerable depths over periods
comparable with the lifetime of the planet. The process of desiccation is
controlled by the rate at which H2O molecules can diffuse through the
regolith, which in turn depends on the nature of the porosity, i. e. the
size of the pore voids. Subsurface sounding mesurements of water vapor
content will be made from the martian surface in situ., and will provide
interesting corroborative evidence in support of this scenario.

From this very brief account of the physical/thermodynamic state of the
regolith of Mars it is clear that ice can exist close to the surface at
higher latitudes. Near the equator the ice is likely to exist only at some
considerable depth, if at all. Furthermore there is probably a lower edge
to the cryolithosphere below which the water can exist in fluid form. The
physical evidence discussed so far is not the only one to support the
notion that large amounts of water ice exists at some depth under the
surface of Mars.
[pic]
Figure 1.1 Example of the desiccation of the surface layers as a function
of time, starting with a uniform layer of ice, showing the migration of the
ice toward higher latitudes. (Fanale et al, 1986)

1.1.5 Rampart Craters
Studies of rampart craters and periglacial features suggest that a large
amount of ground ice should be present within the Martian megaregolith
(Kuzmin et al.,1988; Rossbacher and Judson, 1981; Squyres et al., 1992).
Due to sublimation processes and the porous nature of the megaregolith, the
ground ice table is covered with a dry layer. One of the most obvious
indications of volatiles at depth are provided by rampart craters.
According to Boyce (1980) and Kuzmin (1980), the minimum rampart crater
size may be an indicator of the depth to which an impact event must
excavate the regolith to reach the ground ice table. The rampart crater
distribution indicates a meridional distribution of the depth to the ground
ice table with deep ground ice at equatorial latitudes and near surface
ground ice at mid and high latitudes. The top of the ground ice layer is
found at a depth exceeding 0.3 kilometer at equatorial latitudes and 150
meters for high latitudes, with a minimum value of 30 meters in Acidalia
Planitia and Utopia Planitia. (Costard and Kargel, 1995) There is a
discontinuity in the depth of ground ice near latitude 35?-40? which might
be related to the stability of near-surface ground ice, as the soil never
reaches the frost point during the year poleward of about 40? and is
therefore in equilibrium with the atmosphere. In this case, water is always
stable as ice. These morphologic observations agree with the theoretical
calculations of the distribution of volatiles within the crust (Squyres et
al., 1992; Clifford, 1993).

Rampart crater distribution reveals that type 1 rampart craters (single
continuous and multilobate ejecta with peripheral ridges). together with
low mobility ejecta, are frequently observed in the equatorial region.
There is a good relationship between type 1 ejecta and ridged plains for
Coprates, Lunae Planum, Western Amazonis, Chryse Planitia, South Elysium
and Syrtis Major. These observations suggest that the near-surface
materials contain fewer volatiles than the underlying materials (Horner