BACK TO THE GARDEN:
June 13, 2000
NASA GOES FROM PLANTS TO PLANETS
Headquarters, Washington, DC
Jet Propulsion Laboratory, Pasadena, CA
BACK TO THE GARDEN: NASA GOES FROM PLANTS TO PLANETS
NASA scientists have gone back to the garden, "planting"
wireless webs of small sensors in gardens here on Earth in
preparation for missions to help monitor biological activity on
Sensor webs like those being tested will help make possible a
key NASA goal to establish a virtual presence for exploration
throughout the solar system.
NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA, and the
Huntington Library, Art Collections, and Botanical Gardens, San
Marino, CA, have joined forces to study micro-climates, placing
webs in the various specialized gardens at the Huntington.
Like satellites and telescopes remotely "measuring" planets
across the vast reaches of space, the webs allow large areas to be
monitored. Unlike remote operations, sensor webs are placed
inside the environment -- thus making them capable of on-site
detection not possible from afar. For example, satellite
measurements cannot penetrate deep below the ocean surface or
detect extremely small quantities of gases coming off a planetary
surface. The sensor webs could combine the spatial coverage of a
satellite with the precision of an on-site instrument.
"Sensor webs offer us the means to make sensitive
measurements over large areas," said Dr. Kevin Delin, leader of
the Sensor Webs Project at JPL. "A major thrust of our current
effort is to develop a sensor web that can detect, identify and
monitor any biological activity. For example, trace biosignature
gases are very important if you are a biogeochemist trying to
understand the carbon cycle on Earth or searching for
microorganisms living beneath the surface of a planet."
A sensor web consists of a number of small pods, each housing
transducers that collect data from the environment and
communication chips that move the data around the web to primary
pods. The information is then transmitted to the Internet or an
overhead satellite. "Hopping" the data in short distances from
pod to pod makes the overall data transmission more energy
efficient. In addition, the "hopped" data is shared by all of the
pods, allowing each one to know what is being collected elsewhere
on the web.
The pods being tested monitor local temperature, humidity,
soil moisture and light levels. Initial observations will take
place in a controlled greenhouse environment, then progress to a
nursery, and on to overlapping microclimate areas. Pods are
housed in small plastic containers about the size of a sandwich
box. Other sensor web pods developed by Delin and Shannon
Jackson, also of JPL and the lead engineer on the project, look
much like a gumball toy, but contain specialized instruments.
The Huntington Botanical Gardens is a "perfect place," says
Delin, to field test the sensor web since there are varied garden
environments in the 150-acre grounds that reflect many different
micro-climates, from desert to semi-tropical to cool. "We are
quite fortunate to be able to work with the staff at the
Huntington Gardens to test our system, since they are so
experienced in botanical research," Delin said.
This collaboration between institutions is mutually
beneficial, according to James Folsom, Director of the Botanical
Gardens. "It's always great to work with the scientists from JPL,
even more so in this instance. The Huntington's staff sees
remarkable potential for the development of these sensors, in both
field study and gardens management."
Another advantage to wireless sensor webs is the easy
replacement of modules when sensor instruments degrade or
batteries fail. New modules, including primary ones, can be added
to the web at any time. Multiple webs deployed in a given area
will easily mesh with each other. On Earth, webs could be dropped
from an airplane, while for other bodies in the solar system, the
webs could be released from spacecraft, fired from a lander, or
dropped from a small rover. Another possibility is ballistically
driving the modules into the steep sides of a canyon for
measurements in inaccessible areas.
JPL is a division of the California Institute of Technology,
The Huntington is a private, nonprofit research and cultural
center serving both scholars and the general public. The
institution is dedicated to the study of history, literature, art,
science and culture, as well as to botanical research and
Images associated with this release are available on the