Science and technology applications for the Moon have not fully kept pace with technical advancements in sensor development and analytical information extraction capabilities. Appropriate unanswered questions for the Moon abound, but until recently there has been little motivation to link sophisticated technical capabilities with specific measurement and analysis projects. Over the last decade enormous technical progress has been made in the development of (1) CCD photometric array detectors; (2) visible to near-infrared imaging spectrometers; (3)infrared spectroscopy; (4) high-resolution dual-polarization radar imaging at 3.5, 12, and 70 cm; and equally important (5) data analysis and information extraction techniques using compact powerful computers. Parts of each of these have been tested separately, but there has been no programmatic effort to develop and optimize instruments to meet lunar science and resource assessment needs (e.g., specific wavelength range, resolution, etc.) nor to coordinate activities so that the symbiotic relation between different kinds of data can be fully realized. No single type of remotely acquired data completely characterizes the lunar environment, but there has been little opportunity for integration of diverse advanced sensor data for the Moon. Two examples of technology concepts for lunar measurements are given. Using VIS/near-IR spectroscopy, the mineral composition of surface material can be derived from visible and near-infrared radiation reflected from the surface. The surface and subsurface scattering properties of the Moon can be analyzed using radar backscattering imaging

Pieters, Carle M.

English

NASA Technical Reports Server

42 New Technologies for Lunar Resource Assessment
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WT. MEAN MAGNETIC SUSCEPTIBILITY (10 CC/GM)
O.t 0.2 0.3 0.4 0.5 0.6 0.7 0.8
POUNDS OF ANORTHITE PER POUND OF SOIL
Fig. 1. Anortfme separation from highland soils.
*<tt<MJi.
A'/FeO Versus Is/FeO
0 10 20 30 *0 SO 60 70 80 9O 100 110 120
Lunar Soil Matunly Parameter (ls/FeO)
Fig. 2. X/FeO vs. soil maturity.
elation. The measurement is more amenable to in situ measure-
ment than is ferromagnetic resonance.
There are many ways to measure magnetic susceptibility that
could be incorporated in mobile soil characterization packages.
Instrumentation to detect separable ilmenite might combine mag-
netic susceptibility and X-ray methods to measure iron and ti-
tanium. Measurements could be made on soil samples or on core
samples for rapid determination of maturity. This would permit
a quick assessment of the potential for magnetic separation of
selected mineral components.
References: [ 1 ] Oder R. R. et al. (1989) LPSC XX, 804-805;
Oder R. R. and Taylor L. A. (1990) In Engineering, Construction
and* Operation in Space // (S. W. Johnson and J. P. Wetzel, eds.),
143-152, American Society of Civil Engineers, New York. [2) Oder
R. R. and Jamison R. E. (1989) Final Report, Phase ISBIR Program,
NASA Contract NAS 9-18092. [3] Oder R. R. (1991) IEEE
Tnmsactions on Magnetics; Oder R. R. (1991) AIME-SME Annual
Meeting, Denver.
THE QUICKEST, LOWEST-COST LUNAR RESOURCE
ASSESSMENT PROGRAM: INTEGRATED HIGH-TECH
EARTH-BASED ASTRONOMY. Carle M. Pieters and the
PRELUDES Consortium, Brown University, Providence RI02912,
USA.
Introduction and Recommendations: Science and technol-
ogy applications for the Moon have not fully kept pace with
technical advancements in sensor development and analytical
information extraction capabilities. Appropriate unanswered ques-
tions for the Moon abound, but unt i l recently there has been
little motivation (funding) to link sophisticated technical capa-
bilities with specific measurement and analysis projects. Over the
last decade enormous technical progress has been made in the
development of (1) CCD photometric array detectors, (2) visible
to near-infrared imaging spectrometers, (3) infrared spectroscopy,
(4) high-resolution dual-polarization radar imaging at 3.5, 12, and
70 cm, and equally important, (5) data analysis and information
extraction techniques using compact powerful computers. Parts
of each of these have been tested separately, but there has been
no programmatic effort to develop and optimize instruments to
meet lunar science and resource assessment needs (e.g., specific
wavelength range, resolution, etc.) nor to coordinate activities so
that the symbiotic relation between different kinds of data can
be fully realized. No single type of remotely acquired data com-
pletely characterizes the lunar environment, but there has been
little opportunity for integration of diverse advanced sensor data
for the Moon.
Recommendation. A research and analysis program to survey
potential resource sites on the lunar nearside is recommended that
would include aggressive instrument development and acquisition
and analysis of advanced sensor data obtained for the Moon with
optical, infrared, and radar telescopes. Coordinated acquisition and
integration of advanced sensor data can provide synoptic infor-
mation necessary to assess regional compositional diversity, local
regolith character, and geologic context of sites on the lunar
nearside that have high potential for lunar resources. The cost
of such an R&A program is estimated to be about $5 million per
year. This program includes an instrument development and
upgrade program during the first year, and calibration and initial
data products by the second year. The broad nature of the program
exercises expertise gained during and since Apollo and provides
https://ntrs.nasa.gov/search.jsp?R=19930008072 2020-03-24T07:24:10+00:00Z
LPI Technical Report 92-06 43
TABLE I. Evolution of VIS/near-IR spectroscopy of the Moon.
Date' Person/Group Capability Range Min. Resol.
" First publication/presentation.
Spectral range: V = visible (0.4-0.7 urn); xV = extended visible (0.32-1.1 >im); nlR = near infrared (0.6-2.6
—Coverage
1912
1968
1970
1970
1976
1977
1980
1989
1990
1990
1990
R. W. Wood
T. B. McCord
L. A. Soderblom
McCord/Johnson
McCord et al.
McCord/Pieters
McCord et al.
French/Germans
Lucey et al.
Galileo SSI team
Galileo N1MS team
Photographic color
PMT <25-color spot
3-color image scan
~50-color spot
3-color vidicon
Vidicon spectrometer/
polarimeter
128-color single spot
3-10-colorCCD
CCD spectrometer
CCD imaging (spacecraft)
Stepped I' spectrometer
V
xV
V
xV + nlR
xV
xV
xV
nlR
xV
xV
xV
nIR+
-30 km
20km
20km
20km
2 k m
2 k m
5 k m
5km
1 km
2 k m
5 k m
100km
Nearside
>100 areas
M. Tranquillitacis
<10 areas
Nearside mare
100 km linear
<20 areas
> 100 areas
100 X 100 areas
100 km linear
1/2 Moon
1/2 Moon
young scientists the experience necessary to carry out the proposed
more complete global assessment of the Moon to be acquired from
orbital spacecraft.
Reasons for implementation of an aggressive R&A lunar astronomy
program in the currenl environment. (1) SEI. The information
produced has immediate and direct input into the Space Explo-
ration Initiative (SEI). It provides an early broad assessment of
potential lunar sites that cannot be easily achieved by other means
on a timescale that is immensely valuable to the decision-making
process. It is visible activity showing immediate results for the SEI
program and is excellent preparation for the important, more
detailed program of orbital measurements. (2) Technology Devel-
opment. The proposed R&A program drives U.S. advanced sensor
development and use with significant real applications. Integration
and analysis of complex advanced sensor data are essential capa-
bilities that need to be developed and tested. Experience gained
from the project will give a head start to the technical needs for
later detailed analysis of global systems (Earth, Moon, Mars).
(3) Science Education. The program will contain heavy university
involvement and provide an active research environment essential
for the training, of new lunar scientists. Highly technical activities
with a focus on lunar science will significantly expand the number
of young scientists appropriately trained for lunar science and
exploration by the turn of the century.
Two Examples of Technology Concepts for Lunar Measure-
ments: WS/near-/R spectroscopy. The mineral composition of
surface material can be derived from visible and near-infrared
radiation reflected from the surface. The source of radiation is
the Sun and the capabilities of the detector system determine
the type of information derived. Solar radiation interacts with
the first few millimeters of material and is altered by the absorption
properties inherent to the surface material. When the reflected
radiation is analyzed with high spectral resolution, broad absorp-
tion bands are detected that are highly diagnostic of the minerals
present on the surface. For lunar materials, most major rock types
can be readily distinguished based on the mineral absorption bands
present in their spectra.
As summarized in Table 1, the color of the Moon has been
under study since the early part of this century. When photo-
electric detectors became available in the late 1960s and 1970s
the spectral properties of different areas on the Moon were
measured quantitatively. Until infrared detectors were available
in the late 1970s and early 1980s, spectral analyses were limited
largely to distinguishing different units on the surface based on
color differences in the extended visible range of the spectrum.
Framing cameras using two-dimensional silicon detectors (vidicons
and CCDs) allowed the extent of distinct surface units to be
mapped. With the development of high-spectral-resolution near-
infrared spectrometers, the diagnostic mineral absorption bands
could be identified and the composition of the surface charac-
terized. Such studies flourished in the 1980s, with significant
science return using point spectrometers, with which the spectrum
of an individual lunar area 3-20 km in diameter is measured and
surface composition of that location analyzed.
Current technology allows both the spatial extent of surface
units and the compositional character of surface material to be
analyzed with an advanced sensor called an imaging spectrometer.
Such instruments have been developed and successfully flown on
aircraft for terrestrial applications, but none have been designed
and bui l t to specifically meet lunar exploration needs. An imaging
spectrometer utilizes recent advancements in detector develop-
ment and optical design to obtain an "image cube" of data (two
dimensions of spatial information and one dimension of spectral
information). For lunar applications the design should include
high-spatial (1-2 km) and high-spectral (10 nm) resolution from
the visible through the near-infrared, where most diagnostic ab-
sorption bands occur.
TABLE 2. Evolution of radar measurements for the Moon.
Dates Capability Resolution Nearside Coverage
1946
1962
1964-1972
1980-1983
1985-1991
First detection
Crater Tycho detected
Backscatter .imaging 7.5 m
Backscatter imaging 70 cm
Backscatter imaging 3.8 cm
Topography imaging 3.8 cm
Backscatter imaging 70 cm
Backscatter imaging 70 cm
Backscatter imaging 12.6 cm
Backscatter imaging 3.8 cm
Bulk Moon
10km
40km
10km
2 k m
2 k m
2 k m
500m
300m
50m
Near global
Global
Global
Local targets
Global
Local targets
Local targets
(In progress)
44 New Technologies for Lunar Resource Assessment
Radar backscatter. The surface and subsurface scattering prop-
erties of the Moon can be analyzed using radar backscatter imaging.
The radiation is both transmitted and received by Earth-based
radar antennae. Two-dimensional backscatter images are derived
using a delay-doppler technique developed in the 1960s and 1970s.
The returned signal is directly related to the geometry of the
measurements, the number of scatterers encountered on the scale
of the wavelength, and the dielectric properties of surface mate-
rials. Surfaces that are smooth on the scale of the wavelength
reflect the radiation in a specular manner. Surfaces containing
abundant scattering elements on the scale of the wavelength
return a higher signal. Since the lunar surface is anhydrous,
subsurface block population can also be detected with longer
wavelengths.
As summarized in Table 2, radar measurements of the Moon
have also had a long history with several important milestones.
First was simply the detection of the Moon with Earth-based
instruments. As technology advanced during the 1960s and 1970s,
the techniques for measurement of radar backscatter of the Moon
were perfected and two-dimensional images of the radar back-
scatter properties were produced at relatively low spatial re-
solution. Analyses of dual-polarization radar data confirmed the
sensitivity to block population on the surface. The last several
years have seen dramatic improvement of radar measurements
possible. These include an improvement in both sensitivity and,
more important for lunar measurements, an improvement in the
spatial resolution that can be obtained with Earth-based telescopes.
Current technical capabilities indicate that a spatial resolution
of 30-300 m is possible for lunar nearside targets (optical telescopes
can achieve 1-km resolution; Lunar Orbiter IV obtained ~IOO-m
resolution for the lunar nearside from orbit). Several tests of these
new radar capabilities have already been made. In order to achieve
the desired resolution and science analysis return, a modest upgrade
to current radar telescopes is required to allow dual polarization
at three wavelengths and more extensive data analyses (informa-
tion extraction) capabilities need to be developed for lunar specific
LUNAR SURFACE ROVERS. J. B. Plescia, A. L. Lane, and
D. Miller, Jet Propulsion Laboratory, California Institute of Tech-
nology, Pasadena CA 91109, USA.
Despite the Ranger, Lunar Orbiter, Surveyor, Apollo, Luna, and
Lunokhod programs, many questions of lunar science remain
unanswered because of a lack of specific data. With the potential
for returning humans to the Moon and establishing a long-term
presence there, a new realm of exploration is possible. Numerous
plans have been outlined for orbital and surface missions. Here
we describe the capabilities and objectives of a smallclass of rovers
to be deployed on the lunar surface. The objective of these small
rovers is to collect detailed in situ information about the com-
position and distribution of materials on the lunar surface. Those
data, in turn, would be applied to a variety of lunat geoscience
questions and form a basis for planning human activities on the
lunar surface.
The initial rover design has been scoped for a small Artemis
lander payload (about 60 kg). It consists of a four- or six-wheeled,
solar-powered rover with a mass of 28 kg. Two rovers would be
deployed from a single Artemis lander. Rover lifetime would be
at least 3 lunar days and hopefully 7-10; at least tens of kilometers
of range are possible (depending upon the amount of time devoted
to moving vs. sampling and analysis). During the lunar night, the
rover would hibernate. About II kg of the total 28 kg is available
for science payload and sampling equipment, which allows for a
variety of capabilities that capitalize on microtechnology. Rover
speed would be 0.5-1.0 km/hr depending upon the tetrain. Power
(60-200 W) is provided by solar panels (0.3 m2) that also serve
to shield the rover from high thermal loads during the day.
IZOWhr of AgZn batteries provide capability for short-period,
high-load demands; these batteries are capable of withstanding
the lunar night. Nominal data rate would be about 30 kbps at
20 W RF; rates as high as 150 kbps would be possible for limited
periods. Control of the rover mobility would be in two modes:
behavioral control dtivingand teleoperation dtiving. In the behav-
ior control mode, a series of way points would be selected and
the rover would navigate along the predetermined path, to a site,
invoking autonomous obstacle avoidance if necessary. In the tel-
eoperation driving mode, mobility would-be controlled in a real-
time sense from the Earth using slow-scan video for viewing.
Sampling and deployment would all be done autonomously once
a specific action and position had been selected from the ground.
The system would not make autonomous decisions about meas-
urement or sampling.
Two types of payloads are envisioned for such a small rover:
a geoscience payload and a physical properties payload. The nom-
inal geoscience payload is aimed at addressing the chemical and
mineralogic properties of the regolith and tocks, the composition
of absorbed and adsorbed gases in the regolith, and the morphology
of the surface to millimeter scale. The payload includes stereo
imaging, field lens camera, infrared imaging spectrometer, evolved
gas analysis, and alpha/proton/X-tay fluorescence instruments, as
well as a scoop and an auger drill to obtain samples of the upper
meter of regolith. Using these data, several questions can be
addressed: geochemical and petrological processes; regolith stra-
tigraphy and development; history of the solar-wind-implanted
gases; lunar resources; small-scale surface morphology; and site
evaluation.
Steteo imaging is achieved through two mast-mounted CCD
framing cameras (800 X 1000 pixels) with a separation of about
25 cm. Mast mounting allows 360° horizontal viewing and 120°
of vertical viewing. The field lens camera is the same type of camera
but mounted on the rover body with optics that allow imaging
at a resolution of a few millimeters in the near field. The infrared
imaging spectrometer covers the spectral range of 0.7 to 2.5 /jm
and focuses on the portion of the spectrum sensitive to pyroxenes,
olivines, FeO content, and soil composition. A spatial resolution
of <2 mm at 30 cm is possible. The alpha/proton/X-ray fluores-
cence instrument is aimed at obtaining elemental composition.
The alpha/proton mode measures low Z elements, whereas the
X-ray fluorescence mode is sensitive to higher Z elements. Curium-
244 is used as the source for the alpha particles; l09Cd or I44Cm
would be used for the X-ray excitation. The evolved gas analysis
system would be used to heat the samples to drive off gases that
would then be analyzed by a mass specttometer or other system.
Target gases include H2,3He, SO2, CO, CO2, H,S, H2O, and N,.
Two types of sample acquistion equipment are planned: a scoop
and a drill. The scoop is a clamshell mounted on a 4 degree-of-
freedom arm and would collect samples for analysis to depths of
a few centimeters with a sample volume of a few cubic centi-
metets; it could also be used for shallow trenching. This same
arm would also deploy the alpha/proton/X-ray device to the
surface. The drill is an auger drill mounted to the rover body that


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