An instrumentation, called Space Active Modular Materials ExperimentS (SAMMES), is developed for monitoring the spacecraft environment and for accurately measuring the degradation of space materials in low earth orbit (LEO). The SAMMES architecture concept can be extended to instrumentation for planetary exploration, both on spacecraft and in situ. The operating environment for planetary application will be substantially different, with temperature extremes and harsh solar wind and cosmic ray flux on lunar surfaces and temperature extremes and high winds on venusian and Martian surfaces. Moreover, instruments for surface deployment, which will be packaged in a small lander/rover (as in MESUR, for example), must be extremely compact with ultralow power and weight. With these requirements in mind, the SAMMES concept was extended to a sensor/instrumentation scheme for the lunar and Martian surface environment

Joshi, P. B.

English

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LPI Technical Report 93-02 11
This presentation will detail an application of these black surfaces
to the Clementine star-tracker navigational system, which will be
launched in early 1994 to examine the Moon, en route to intercept
an asteroid. Rugged black surfaces with Lambertian BRDF <10-2
srad-' are critical for suppressing stray light in the star-tracker
optical train. Previously available materials spall under launch
vibrations to contaminate mirrors and lenses. Microtextured alumi-
num is nearly as dark, but much less fragile. It is made by differential
ion beam sputtering, which generates light-trapping pores and cones
slightly smaller than the wavelength to be absorbed. This leaves a
sturdy but light-absorbing surface that can survive challenging
conditions without generating debris or contaminants. Both seeded
ion beams and plasma immersion (from ECR plasmas) extraction
can produce these microscopic textures without fragile interfaces.
Process parameters control feature size, spacing, and optical effects
(THR, BRDF). Both broad and narrow absorption bands can be
engineered with tuning for specific wavelengths and applications.
Examples will be presented characterized by FTIR in reflection
mode. Textured metal blacks are also ideal for blackbody calibrators
(0.95 normal emissivity), heat rejection, and enhanced nucleate
boiling.
V NEW TECHNOLOGIES F O R j DETECTORS. C. L.
Joseph, Space Astronomy Laboratory, University of Wisconsin,
1 150 University Avenue, Madison WI 53706, USA.
Several technologies are currently being developed, leading to
substantial improvements in the performance of UV detectors or
significant reductions in power or weight. Four technologies dis-
cussed are (1) thin-film coatings to enhance the UV sensitivity of
CCDs, (2) highly innovative magnet assemblies that dramatically
reduce weight and result in virtually no external flux, (3) new
techniques for curving microchannel plates (MCPs) so that single
plates can be used to prevent ion feedback and present highly
localized charge clouds to an anode structure, and (4) high-perfor-
mance alternatives to glass-based MCPs. In item (2), for example,
very robust magnets are made out of rare earth materials such as
samarium cobalt, and cladding magnets are employed to prevent
flux from escaping from the detector into the external environment
These new ultralight magnet assemblies are able to create strong,
exceptionally uniform magnetic fields for image intensification and
focusing of photoelectrons. The principle advantage of such detec-
tors is the quantum efficiencies of 70-80% obtained throughout
ultraviolet wavelengths (900-2000 A), the highest of any device.
Despite the improvements achieved under item (3), high-perfor-
mance alternatives to conventional glass-based MCPs potentially
offer three distinct new advantages that include (1) a 30-100-fold
improvement in dynamic range resulting in correspondingly higher
signal-to-noise ratios, (2) the use of pure dielectric and semiconduc-
tor materials that will not outgas contaminants that eventually
destroy photocathodes, and (3) channels that have constant spacing
providing long-ranged order since the plates are made using photo-
lithography techniques from the semiconductor industry. The manu-
facturers of these advanced-technology MCPs, however, are a
couple of years away from actually producing a functioning image
intensifier.
In contrast to the use of CCDs for optical, groundbased observa-
tions, there is no single detector technology in the ultraviolet that
dominates or is as universally suitable for all applications. Thus, we
address several technological problems, recent advances, and the
impact that these new enabling technologies represent for UV
applications.
LIGHTWEIGHT MODULAR INSTRUMENTATION FOR
PLANETARY APPLICATIONS. P. B. Joshi,Physical Sciences
Inc., 20 New England Business Center, Andover MA 01810, USA.
Physical Sciences Inc. is currently developing under SDIO
sponsorship an instrumentation suite for monitoring the spacecraft
environment and for accurately measuring the degradation of space
materials in LEO. The instrumentation, called SAMMES (Space
Active Modular Materials Experiments), features compact (~6-in
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 Sensor (Total Dose)
• System control module not needed
for autonomic Instrument modules
• Sensors can be on module or
remotely wired to module
• RS 422 Command/Data Interface
between modules and lander/controller
Fig. 1. Sensor/instrumentation concept for lunar/martian application.
https://ntrs.nasa.gov/search.jsp?R=19930019598 2020-03-24T07:39:00+00:00Z
12 Workshop on Advanced Technologies for Planetary Instruments
cube), lightweight (~2.5 kg) modules incorporating a variety of
sensors and low-power (~5 W) processing electronics. The LEO
Environment Monitor Module (EMM) sensor complement consists
of two passively called Quartz Crystal Microbalances and three
calorimeters for contaminant detection/characterization, three acti-
nometers for measuring AO flux, two RADFETs for total dose
radiation measurement, a Sun position sensor, and a solar irradiance
sensor. The EMM is designed as a remote terminal for MIL-STD-
1553B communication with an experiment bus controller and for
independent operation of its sensors. The present design can be
modified to be fully autonomous, with module-based mass memory,
onboard data processing, and software upload capability.
The SAMMES architecture concept can be extended to instru-
mentation for planetary exploration, both on spacecraft and in situ.
The operating environment for planetary application will be sub-
stantially different, with temperature extremes and harsh solar wind
and cosmic ray flux on lunar surfaces and temperature extremes and
high winds on venusian and martian surfaces. Moreover, instru-
ments for surface deployment, which will be packaged in a small
lander/rover (as in MESUR, for example), must be extremely
compact with ultralow power and weight. With these requirements
in mind, we have extended the SAMMES concept to a sensor/
instrumentation scheme for the lunar and martian surface environ-
ment, as illustrated in Fig. 1 •
OPTICAL TECHNOLQG'IES FOR UV REMOTE SENSING
INSTRUMENTS. R. A. M. Keski-Kuha, J. F. Osantowski, D. B.
Leviton, T. T. Saha, D. A. Content, R. A. Boucarut, J. S. Gum, G. A.
Wright, C. M. Fleetwood, and T. J. Madison, NASA Goddard Space
Flight Center, Greenbelt MD 2077 1 , US A.
Over the last decade significant advances in technology have
made possible development of instruments with substantially im-
proved efficiency in the UV spectral region. In the area of optical
coatings and materials, we discuss the importance of recent devel-
opments in chemical vapor deposited (CVD) silicon carbide (SiC)
mirrors, SiC films, and multilayer coatings in the context of
ultraviolet instrumentation design. For example, the development
of chemically vapor deposited (CVD) silicon carbide (SiC) mirrors,
with high ultraviolet (UV) reflectance and low scatter surfaces,
provides the opportunity to extend higher spectral/spatial resolution
capability into the 50-nm region. Optical coatings for normal
incidence diffraction gratings are particularly important for the
evolution of efficient extreme ultraviolet (EUV) spectrographs. SiC
films are important for optimizing the spectrograph performance in
the 90-nm spectral region.
Diffraction grating technology has always played a pivotal role
in the development of spectroscopic instrumentation for ultraviolet
space flight instrumentation. An essential element in the successful
diffraction grating development program is the ability to quantita-
tively evaluate the performance of test diffraction gratings in the
early stages of the instrument development program. The Diffrac-
tion Grating Evaluation Facility (DGEF) at Goddard Space Right
Center was established to evaluate the performance of new technol-
ogy diffraction gratings and other optical components for future
spaceflight instrumentation especially in the vacuum ultraviolet.
DGEF is a unique, world-class, extremely versatile facility with
enormous evacuable optical set-up volume allowing mirrors and
gratings to be evaluated in their design configurations with respect
to design specifications, manufacturer's data, and optical analytical
results.
We will discuss the performance evaluation of the flight optical
components for the Solar Ultraviolet Measurements of Emitted
Radiation (SUMER) instrument, a spectroscopic instrument to fly
aboard the Solar and Heliospheric Observatory (SOHO) mission,
designed to study dynamic processes, temperatures, and densities in
the plasma of the upper atmosphere of the Sun in the wavelength
range from 50 nm to 160 nm. The optical components were
evaluated for imaging and scatter in the UV. We will also review the
performance evaluation of SOHO/CDS (Coronal Diagnostic Spec-
trometer) flight gratings tested for spectral resolution and scatter in
the DGEF and present preliminary results on resolution and scatter
testing of Space Telescope Imaging Spectrograph (STIS) technology
development diffraction gratings.
MULTISCALE MORPHOLOGICAL FILTERING FOR
ANALYSIS OF NOISY AND COMPLEX IMAGES. A. Kher
and S. Mitra, Computer Vision and Image Analysis Laboratory,
Department of Electrical Engineering, Texas Tech University,
Lubbock TX 79410, USA.
Images acquired with passive sensing techniques suffer from
illumination variations and poor local contrasts that create major
difficulties in interpretation and identification tasks. On the other
hand, images acquired with active sensing techniques based on
monochromatic illumination are degraded with speckle noise. Math-
ematical morphology offers elegant techniques to handle a wide
range of image degradation problems. Unlike linear filters, morpho-
logical filters do not blur the edges and hence maintain higher image
resolution. Their rich mathematical framework facilitates the de-
sign and analysis of these filters as well as their hardware imple-
mentation. Morphological filters are easier to implement and are
more cost effective and efficient than several conventional linear
filters. Morphological filters to remove speckle noise while main-
taining high resolution and preserving thin image regions that are
particularly vulnerable to speckle noise [ 1 ] have been developed and
applied to SAR imagery. These filters used combination of linear
(one-dimensional) structuring elements in different (typically four)
orientations (the median operators by Maragos [2]). Although this
approach preserves more details than the simple morphological
filters using two-dimensional structuring elements, the limited
orientations of one-dimensional elements approximate the fine
details of the region boundaries. A more robust filter designed
recently overcomes the limitation of the fixed orientations. This
filter uses a combination of concave and convex structuring ele-
ments. Morphological operators are also useful in extracting fea-
tures from visible and infrared imagery. A multiresolution image
pyramid obtained with successive filtering and a subsampling
process aids in the removal of the illumination variations and
enhances local contrasts. A morphology-based interpolation scheme
has also been introduced to reduce intensity discontinuities created
in any morphological filtering task. The generality of morphological
filtering techniques in extracting information from a wide variety of
images obtained with active and passive sensing techniques will be
discussed. Such techniques are particularly useful in obtainingmore


Lightweight Modular Instrumentation for Planetary Applications

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