Interdisciplinary Scientists Propose Paradigm Shift in Robotic SpaceExploration (Forwarded)

Media Relations
Caltech

Contact:
Robert Tindol, (626) 395-3631

October 17, 2005

Interdisciplinary Scientists Propose Paradigm Shift in Robotic Space
Exploration

PASADENA, Calif. -- Just ask any geologist. If you're studying the
history of a planet and the life forms that may have lived on it, the
really good places to look are rugged terrains like canyons and other
areas where water, igneous activity, wind, and seismic rumblings have
left their respective marks. Flat is not so good.

But when it comes to exploring other worlds, like Mars, the strategy for
ground-based reconnaissance thus far has been to land in relatively
smooth places so the spacecraft won't slam into something vertical as it
touches down or as it rolls to a stop in its protective airbags. In the
cases of the Mars landings -- and all soft landings on other planets and
moons, for that matter -- flat is definitely good.

To address this disconnect, a team of interdisciplinary scientists from
the California Institute of Technology, the University of Arizona, and
the U.S. Geological Survey has unveiled a proposal to make core changes
in the robotic exploration of the solar system. In addition to
spaceborne orbiters, the "new paradigm" would involve sending
orbiter-guided blimps (or other airborne agents) carrying instruments
such as optical and thermal cameras, ground-penetrating radar, and gas
and humidity sensors to chosen areas of a planet, as well as using herds
of small, robotic, ground-based explorers.

The ground explorers would communicate with the airborne and/or
spaceborne agents, coupled with innovative software for identification,
characterization, and integration of various types of spatial and
temporal information for in-transit comparative analysis, hypothesis
formulation, and target selection. This would lead to a "tier-scalable
perspective," akin to the approach used by field geologists to solve a
complicated geological puzzle.

Writing in an upcoming issue of the journal Planetary and Space Science,
the researchers propose "a fundamentally new scientific mission concept
for remote planetary surface and subsurface reconnaissance." The new
approach will be cost-effective, in that it can include greater
redundancy and thus greater assurance of mission success, while
significantly allowing unconstrained science-driven missions to uncover
transient events (for example, evidence of liquid water) and possible
signs of life on other worlds.

"We're not trying to take anything away from the successful landings on
Mars, Venus, and Titan, nor the orbital-based successes to most of the
planetary bodies of the solar system," says Wolfgang Fink, a physicist
who is serving a multiyear appointment as a visiting associate at
Caltech. "But we think our tier-scalable mission concept will afford
greater opportunity and freedom to identify and home in on geological
and potential astrobiological 'sweet spots.'"

The new paradigm is spearheaded by Fink and by James Dohm, a planetary
geologist in the Department of Hydrology and Water Resources at the
University of Arizona. The team effort includes Mark Tarbell, who is
Fink's associate in Caltech's Visual and Autonomous Exploration Systems
Research Lab; Trent Hare of the U.S. Geological Survey office in
Flagstaff; and Victor Baker, also of the University of Arizona.

"The paradigm-changing mission concept is by no means accidental," Dohm
explains. "Our interdisciplinary team of scientists has evolved the
concept through the profound realization of the requirement to link the
various disciplines to optimally go after prime targets such as those
environments that have high potential to contain life or far-reaching
geological, hydrological, and climatological records."

Fink, for his part, is an expert in imaging systems, autonomous control,
and science analysis systems for space missions. Dohm is a planetary and
terrestrial field geologist, who, based on his experience, has a keen
sense of how and where to study a terrain, be it earthly or otherworldly.

Dohm, who has performed geological investigations of Mars from local to
global scales for nearly twenty years, says the study of the geology of
other planets has been fruitful yet frustrating. "You're not able to
verify the remote-based information in person and uncover additional
information that would lead to an improved understanding of the
geologic, water, climate, and possible biologic history of Mars.

"Ideally, you'd want to look at remote-based geological information
while you walked with a rock hammer in hand along the margin that
separates a lava flow from putative marine deposits, exploring possible
water seeps and moisture embankments within the expansive canyon system
of Valles Marineris that would extend from Los Angeles to New York,
characterizing the sites of potential ancient and present hydrothermal
activity, climbing over the ancient mountain ranges, gathering diverse
rock types for lab analysis, and so on.

"We think we've devised a way to perform the geologic approach on other
planets in more or less the way geologists do here on Earth."

Even though orbiting spacecraft have successfully collected significant
data through instrument suites, working hypotheses are yet to be
confirmed. In the case of Mars, for example, it is unknown whether the
mountain ranges contain rock types other than volcanic, or whether sites
of suspected hydrothermal activity are indeed hydrothermal environments,
or whether the most habitable sites actually contain signs of life.
These questions may be addressed through the "new paradigm."

The interdisciplinary collaboration provides the wherewithal for
thinking out of the box because the researchers are, well, out of the
box. "We're looking at a new way to cover lots of distance, both
horizontally and vertically, and new, automated, ways to put the
gathered information together and analyze it -- perhaps before it even
comes back to Earth," Fink says.

Just how innovative would the missions be? The tier-scalable paradigm
would vary according to the conditions of the planet or moon to be
studied, and, significantly, to the specific scientific goals. "I
realize that several missions in the past have been lost during orbital
insertion, but we think that the worst perils for a robotic mission are
in getting the instruments to the ground successfully," Fink says. "So
our new paradigm involves missions that are not crippled if a single
rover is lost."

In the case of Mars, a typical mission would deploy maneuverable
airborne agents, such as blimps, equipped with existing multilayered
information (geologic, topographic, geomorphic, geophysical, hydrologic,
elemental, spectral, etc.) that would acquire and ingest information
while in transit from various altitudes.

While floating and performing smart reconnaissance (that is, in-transit
analysis of both the existing and newly acquired spatial and temporal
information in order to formulate working hypotheses), the airborne
agents would migrate toward sweet spots, all the while communicating
with the orbiter or orbiters. Once the sweet spots are identified, the
airborne agents would be in position to deploy or help guide
orbiter-based deployment of ground-based agents for further analysis and
sampling.

"Knowing where you are in the field is extremely critical to the
geologic reconnaissance approach," Dohm says.

"Thanks to the airborne perspective and control, this would be less of a
concern within our tier-scalable mission concept, as opposed to, for
example, the case of an autonomous long-range rover on Mars that is
dependent on visible landmarks to account for its current location,"
Fink adds.

The robotic ground-based agents would be simpler and smaller than the
rovers currently being sent to Mars. Though not necessarily any more
robust than the current generation, the agents would be able to take on
rocky and steep terrains simply because there would be several with
varying degrees of intelligence and thereby, would be somewhat
expendable. If a single rover turned over on a steep terrain, for
example, the mission would not be lost.

The stationary sensors would be even more expendable and could collect
information that can be transmitted back to the airborne units and
orbiter or orbiters for comparative analysis of the spatial and temporal
information for redeployment if the units are mobile, or for additional
deployment, such as placing a drill rig in a prime sweet spot in order
to sample possible near-surface groundwater or even living organisms.

And these are just the ideas for planets such as Mars. The researchers
also have multi-tier mission plans for other planets and moons, where
the conditions could be much more harsh.

In the case of Titan, one of Saturn's moons with an atmosphere one and a
half times as thick as Earth's, autonomously controlled airships would
be ideal for exploration, rendering Titan perfectly suited for
deployment of a three-tiered system consisting of orbiters, blimps, and
both mobile and immobile ground-agents, especially in light of the even
longer communication time lag than in the case of Mars.

On Io, the extremely volcanically active atmosphere-void moon of
Jupiter, in contrast, the orbiter-guided deployment of mobile
ground-agents and immobile sensors would be a productive way of
performing ground-based reconnaissance, capturing and studying active
volcanism beyond Earth. In this case, the three-tiered system of
spaceborne-, airborne-, and ground-level would be reduced to the two
tiers of spaceborne- and ground-level.

The advantages of redundancy and data compilation would still provide
huge operational advantages on Io: if some of the ground-agents are lost
to volcanic hazards, for example, those that remain can still identify,
map out, and transmit back significant information, thus rendering the
overall mission a success. The tier-scalable concept is equally
applicable to investigating active processes on Earth that may put
scientists in harm's way, including volcanism, flooding, and other
hazardous natural and human-induced environmental conditions.

The researchers are already in the test-bed stage of trying out advanced
hardware and software designs. But Fink says that much of the technology
is already available, and even that which is not currently available
(the software, primarily) is quite attainable. Further design, testing,
and "ground-truthing" are required in diverse environments on Earth.
Fink and Dohm envision field camps where the international community of
scientists, engineers, mission architects, and others can design and
test optimal tier-scalable reconnaissance systems for the various
planetary bodies and scientific objectives.

"After all, the question is what do you do with your given payload,"
Fink says. "Do you land one big rover, or would you rather deploy
airborne agents and multiple smaller ground-agents that are commanded
centrally from above, approximating a geologist performing tier-scalable
reconnaissance?

"We think the 'tunable' range of autonomy with our tier-scalable mission
concept will be of interest to NASA and the other agencies worldwide
that are looking at the exploration of the Solar System."

The title of the Planetary and Space Science article is "Next-generation
robotic planetary reconnaissance missions: A paradigm shift."

Related Link:

* Artist's conceptions of multi-tiered missions
http://pr.caltech.edu/media/robotics...cspace_01.html