By Bob Granath
NASA's Kennedy Space Center, Florida
NASA's Kennedy Space Center, Florida
Credits: NASA/ Neil Armstrong
Credits: Contour Crafting and University of Southern California
When early explorers crossed vast oceans to reach new worlds, they
traveled with only what they needed to get there. After arriving at
their destination, the pioneers planned to live off the land. NASA
engineers and scientists now are developing capabilities needed once
astronauts reach destinations such as an asteroid, the moon or Mars.
At NASA's Kennedy Space Center in Florida, researchers are studying
how to best practice in-situ resource utilization (ISRU), that is,
harvesting and relying on available raw materials as astronauts visit
deep-space destinations.
Josephine Burnett, director of Kennedy's new Exploration Research and
Technology Programs organization, points out the significance of
creating new capabilities.
"Pioneering space will require several game changing technologies,
some of which are being developed here at Kennedy," said Burnett. "These
new technological capabilities will enable NASA to become less
dependent on Earth-based logistics and instead use local resources to
maintain a sustained human presence in space."
According to Jack Fox, chief of the Science and Technology Projects
Division of the Exploration Research and Technology Programs Directorate
at Kennedy, ISRU could reduce the weight of an outfitted exploration
spacecraft by 40 percent.
"The purpose of our in-situ resource utilization research is to
harness these resources," he said. "When the early settlers came to
North America, they brought only ax heads. They knew they could make ax
handles from trees they would find when they reached their destination.
We believe learning to live off available resources will significantly
reduce the mass, cost and risk of near and long-term space exploration."
Fox explained that resources such as water ice, metals and regolith
will be available in great supplies whether planning to work on the
moon, Mars or other destinations.
Regolith is a layer of loose material covering solid rock. It
includes dust, soil, broken rock, and other related materials and is
present on Earth, the moon, some asteroids and Mars.
One resource that is key to numerous applications is water.
"Several recent planetary missions have sent back data that points to
lunar water representing a significant resource that could be used by
future explorers," Fox said.
The Clementine mission, launched from Vandenberg Air Force Base in
1994, conducted a bistatic radar experiment that showed water might
exist in the Shackelton crater near the lunar south pole.
Officially called the Deep Space Program Science Experiment, the
objective of the Clementine mission was to test sensors and spacecraft
components under extended exposure to the space environment and to make
scientific observations of the moon and an asteroid.
Launched from Cape Canaveral Air Force Station in 1998, the Lunar
Prospector mission detected elevated amounts of hydrogen in both of the
moon's polar regions, but could not distinguish its chemical form. Other
data returned during the mission also helped scientists construct a
detailed map of the lunar surface composition.
NASA's mini-RF and M3 instruments on the Indian Space
Research Organization's Chandrayaan-1 lunar orbiter provided more
information on the moon's water resources. Chandrayaan-1 was India's
first lunar probe, launched in 2008,
Flown from the Cape in 2009, more potential water resources were
located by the Lunar Reconnaissance Orbiter and the Lunar Crater
Observation and Sensing Satellite (LCROSS) missions.
Besides the obvious benefits of water itself, it is made up of hydrogen and oxygen.
"By separating these elements, we have what it takes to operate fuel
cells to create electricity," Fox said. "That gives us a power plant on a
distant destination."
A fuel cell converts energy from an element, such as liquid hydrogen,
into electricity through a chemical reaction with liquid oxygen or
another oxidizing agent.
Such technology is under development at Kennedy. The Regolith and Environment Science and Oxygen and Lunar Volatiles Extraction (RESOLVE)
payload is in development for a planned Resource Prospector probe. This
ISRU-driven mission features a rover that would map lunar volatiles,
drill to extract samples and process water and other volatiles.
In planetary science, volatiles are chemical elements and compounds
with low boiling points that are associated with a planet or moon's
crust or atmosphere.
"RESOLVE is an important first step in enabling long-duration human
exploration by actually extracting water from under the lunar surface,"
Fox said.
Hydrogen and oxygen are the most efficient chemical rocket
propellants know. Therefore, extracting these elements from local lunar
resources might permit using the moon as a "gas station" for a
spacecraft to explore further into the solar system. Oxygen and water,
obviously represents a valuable life support commodity.
Since 1965, a fleet of robotic spacecraft have flown by, orbited and
landed on Mars. Collectively, they have dramatically increased the
knowledge-base about the Red Planet, helping pave the way for human
pioneers.
Robotic scientific rovers now are being developed to further
determine what raw materials are available and in what quantities. A
prototype rover called RASSOR, for Regolith Advanced Surface System
Operations Robot, has been tested at Kennedy's Swamp Works. Established
to provide rapid, innovative and cost effective exploration mission
solutions, Swamp Works leverages partnerships across NASA, industry and
academia.
"RASSOR is designed to climb over difficult terrain," Fox said. "It
has wheels with scoops that pick up regolith. It could be used to
collect samples or excavate a landing pad for future landers. While the
first generation RASSOR has been very successful, we now are working on
RASSOR 2 which will be lighter in weight and use less energy."
As a resource, regolith shows promise for construction partly due to
the extensive presence of volcanic basalt in the surface soil.
"Construction materials containing basalt and a bonding agent would
be two to three times stronger in compression than normal cement
concrete typically used here on Earth," Fox said. "It would be an
excellent raw material for construction on the moon or Mars."
Fox noted that the strength of basalt in construction is demonstrated
in second-century Roman architecture which has withstood the elements
for centuries.
"We recently teamed with researchers at the Marshall Space Flight
Center and the U.S. Army to study how to use regolith to build
structures to support exploration of Mars," he said.
Planetary surface construction and mining tasks that may be possible
using planetary regolith include launch and landing pads, equipment
shelters, regolith mining for oxygen production, and water ice mining
from shadowed craters.
While NASA develops ways of to use available resources at deep-space
destinations, crews aboard the International Space Station (ISS) are
performing human research experiments and testing advance environmental
and life support systems.
The ability to grow food and recycle carbon dioxide into breathable
oxygen may prove crucial for astronauts and add to the body of knowledge
as they live in space for months or years at a time. A plant habitat
with a large growth chamber also is being studied by Kennedy engineers
to determine the affect long-duration microgravity exposure has on
plants in space. Similarly, projects such as NASA's Veggie pave the way
to growing and eating food in space.
The Veggie experiment is being used aboard the ISS to study the
in-orbit function and performance of a new expandable plant growth
facility.
To continue research into the availability and accessibility of raw
materials for human exploration of Mars, NASA is planning the Mars 2020
mission, building on the success of the Curiosity mission. Scheduled for
launch in 2020, the rover mission goals include detecting and
characterizing ancient environments that could have harbored life,
caching samples for a future sample return mission and testing the
ability to extract oxygen from the Red Planet's carbon-dioxide
atmosphere to prepare for future human exploration.
The Mars Oxygen ISRU Experiment (MOXIE)
will test a solid oxide electrolysis technology that could be scaled up
to meet human mission requirements, while the Mars Environment Dynamics
Analyzer (MEDA) will improve understanding of atmospheric dust.
In addition to NASA and space agencies of other nations, Fox believes
there will be future commercial interest in utilization of resources on
the moon or planets.
"There are so many possibilities for mining raw materials and putting
resources to work, industries may find it economically useful to join
this effort," he said.
Technology investments in space can create new markets, thus stimulating growth of the nation’s economy.
"We know there are solvable challenges for human missions to Mars,"
Fox said. "We have multiple programs in progress that will allow us to
overcome the unknowns and make the best use of what we need to take
along and what we'll find when we get there."
Last Updated: June 4, 2015
Editor: Bob Granath
No comments:
Post a Comment