NASA satellite instruments, that will improve worldwide
climate predictions and provide a better understanding of how
airborne particles and clouds affect our atmosphere, are on
their next-to-last stop toward orbit.
The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite
Observations (CALIPSO) instruments completed a successful
series of ground tests at Ball Aerospace & Technologies
Corp., Boulder, Colo. CALIPSO was then shipped to the Alcatel
Space facility in Cannes, France, where the U.S. and French
payload will be integrated into a Proteus spacecraft
platform.
CALIPSO is expected to give the international science
community a better understanding of clouds and atmospheric
aerosols that influence Earth’s climate. Data from CALIPSO
will help create climate predictions for national and
international leaders to make policy decisions about global
climate change.
“One of NASA’s goals is to understand how the Earth’s climate
system functions and is expected to change in the future,”
said NASA’s David Winker, principal investigator for CALIPSO.
“There are significant uncertainties regarding the role of
clouds and aerosols in the climate system, because it’s
difficult to make the necessary measurements from space.
CALIPSO offers a whole new way of looking at the atmosphere
and overcomes many of the limitations of passive instruments.
It’s like the difference between an X-ray photograph and a
CAT scan, he said.”
The primary instrument on CALIPSO is a three-channel
polarization lidar (light detection and ranging instrument)
that will provide unique information on clouds and aerosols.
Satellite instruments are passive. They observe scattered
sunlight or emitted heat and try to infer the altitude and
properties of aerosols and clouds.
CALIPSO will use a laser to actively sense where they are
located, similar to the way radar works. CALIPSO underwent
active laser testing in early December at Ball Aerospace’s
facilities. “The atmospheric test was extremely successful,”
said Jim Wells, NASA’s Langley Research Center CALIPSO
Atmospheric Test Director. “As a result, NASA has gained
significant confidence in the scientific capabilities of the
CALIPSO payload.”
As a part of the NASA Earth System Science Pathfinder
program, CALIPSO is a collaborative effort with the French
space agency Centre National d’Etudes Spatiales (CNES), Ball
Aerospace, Hampton University and France’s Institut Pierre
Simon Laplace.
Ball Aerospace is responsible for CALIPSO’s scientific
instrument and communications suite, including the lidar and
wide field camera. CNES provided a three-channel imaging
infrared radiometer, will monitor and command CALIPSO on its
36-month mission.
Final testing and launch of CALIPSO is at Vandenberg Air
Force Base, Calf. CALIPSO will share the Delta II rocket in a
dual configuration with NASA’s CloudSat, a satellite that
will use millimeter wave radar to measure cloud properties
from space. Launch is planned for early 2005. CALIPSO and
CloudSat will fly in orbital formation as part of a
constellation of Earth-observing satellites including Aqua,
PARASOL, and Aura, collectively known as the “A-train.”
“Because we’ll fly in formation, measurements from CALIPSO
can also be used to test and improve the accuracy of cloud
and aerosol measurements from the other A-train instruments,”
Winker said. “The height-resolved measurements of aerosols
and clouds from CALIPSO will help to improve our ability to
predict the severity of global warming.”
CALIPSO and other Earth Observing System research is funded
by NASA’s Earth Science Enterprise. The Enterprise is
dedicated to understanding the Earth as an integrated system
and applying Earth System Science to improve prediction of
climate, weather and natural hazards using the unique vantage
point of space. For more information about the mission on the
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