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LAUNCH
DELAYED:
In the routine final preparations and reviews that take place
before a launch, a question arose late on December 16 about
some performance data for one of the electronic boxes on the
launch vehicle. While Boeing investigates and resolves the question,
it was decided to delay the ICESat launch until early January.
NASA'S
READY TO STUDY COOL ICE, HOT PLASMA AND OCEAN WINDS
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ICESat
still image | The
month of December will see the launch of three NASA
research missions to
help us better understand and protect
our home planet while continuing to
search for life in our
universe and inspire the next generation of explorers.
The
ICESat, CHIPS and SeaWinds missions will help improve life
here
while searching for life beyond Earth.
ICESat
(Ice, Cloud and land Elevation Satellite) is the
benchmark NASA mission for
measuring ice-sheet mass balance -- knowledge vital to understanding and protecting
our home
planet.
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2 | | ICESat
still image | The
ICESat mission will use a laser instrument to provide
multi-year elevation
data needed to determine ice-sheet mass
balance. The spacecraft also will
provide surface and
vegetation data around the globe, in addition to specific
coverage over the Greenland and Antarctic ice sheets. ICESat
is due to launch from Vandenberg Air Force Base,
Calif. on Dec. 19 at approximately
7:45 p.m. EST. Once in its
final orbital position, the satellite will orbit
the Earth at
an altitude of approximately 373 miles (600 kilometers). "This
mission will provide revolutionary insight into changes
in ice and the role
ice plays in our Earth system, using a
spaceborne laser to look at the topography
of ice both in the
Antarctic and Greenland," said Dr. Ghassem Asrar,
NASA's
Associate Administrator for Earth Science. "This information
will help scientists determine whether the polar ice sheets
are growing
or shrinking, and how the ice masses may change
under future climate conditions,"
Asrar said. The
Geoscience Laser Altimeter System, or "GLAS" instrument,
on ICESat
will use a laser to measure the time it takes for
light to travel to the
reflecting object and return to the
satellite. The data on the distance to
the surface, the
position of the satellite in space, and the pointing of
the
laser are all combined to calculate the elevation and
position of
each point measurement on the Earth. The laser
will perform these measurements
40 times each second. The
spacecraft was built by Ball Aerospace and Technologies
Corporation (Ball)
in Boulder, Colo. NASA's Earth Science
Data and Information System will provide
space and ground
network support and the University of Colorado's Laboratory
for Atmospheric and Space Physics, Boulder, will team with
Ball to provide
mission operations and flight dynamics
support. The GLAS and ICESat data
will be initially processed
at the ICESat Investigator-led Processing System
facility
with support from the University of Texas's Center for Space
Research, Austin. Launching
with ICESat is NASA's first University-Class
Explorer mission, a suitcase-sized
satellite called the
Cosmic Hot Interstellar Plasma Spectrometer (CHIPS),
designed
to explore the birthplace of solar systems. CHIPS will study
very hot, very low-density gas in the vast spaces between the
stars, known
as the interstellar medium, searching for
important clues about formation
and evolution of galaxies. The
interstellar medium literally contains the seeds of
future stars, and all
the stars we see were once formed out
of the same kind of diffuse gas and
dust. When the gas in the
interstellar medium cools and collapses, the gas
forms clumps
that scientists believe evolve into stars and planets. One of
the biggest puzzles in astrophysics is the process that turns
this very
diffuse, hot and cold gas and dust into stars. Our
solar system is located in a region of space scientists
call the Local Bubble,
which is about 300 light-years in
diameter and is filled with gas much less
dense than the
average interstellar medium. This gas also is extremely hot
-
- about 1.8 million degrees Fahrenheit, or about 180 times as
hot as
the surface of our Sun. It is this extremely diffuse
gas inside the Local
Bubble that the CHIPS mission is
studying. The
CHIPS satellite weighs 60 kilograms (132 pounds) and is
the size of a large
suitcase. It will orbit about 590
kilometers (367 miles) above the Earth
and is expected to
operate for one year. The
CHIPS satellite is sponsored by the Office of Space
Science at NASA Headquarters
in Washington. The CHIPS
instrument was built at the Space Science Laboratory
of the
University of California, Berkeley, and the spacecraft bus
was
built by SpaceDev, Inc. of Poway, Calif. The project is
managed at the NASA
Goddard Space Flight Center's Wallops
Flight Facility, Wallops Island, Va.,
through the NASA
Explorers Program. A
third NASA mission, SeaWinds, is NASA's latest Earth-
monitoring instrument
for measuring the speed and direction
of winds over Earth's oceans. Set to
launch aboard Japan's
Advanced Earth Observing Satellite II (Adeos II) at
8:31 p.m.
EST on Dec.13 from the Tanegashima Space Center, the mission
is expected to yield improved global weather forecasts and
new insights into
various Earth research investigations. "Winds
play a major role in every aspect of Earth's weather,"
Asrar said. "They
directly affect the turbulent exchanges of
heat, moisture and greenhouse
gases between Earth's
atmosphere and the ocean that drive ocean circulation
and
climate. The SeaWinds instrument will provide a critical tool
for
improving weather forecasting, detecting and monitoring
severe marine storms,
identifying subtle changes in the
global climate and better understanding
global weather
abnormalities, such as El Nino and La Nina. NASA is pleased
to partner with Japan on this important endeavor." The
mission will help scientists determine the location,
structure and strength
of severe marine storms -- hurricanes
in the Atlantic, typhoons near Asia
and mid-latitude cyclones
worldwide -- which are among the most destructive
of all
natural phenomena. The National Oceanic and Atmospheric
Administration
(NOAA), a chief mission partner, will use the
data to improve weather forecasting
and storm warnings,
helping forecasters more accurately determine the paths
and
intensities of tropical storms and hurricanes. SeaWinds
will map wind speed and direction across 90 percent
of the Earth's ice-free
oceans every two days. Up to 15 times
a day, Adeos II will beam down SeaWinds
science data to
ground stations operated by NASA and the National Space
Development Agency of Japan, which will relay them to
scientists and weather
forecasters. SeaWinds
is a scatterometer, which transmits high-frequency
microwave pulses to the
ocean surface and measures the
"backscattered," or echoed, pulses
as they are bounced back
to the satellite. The instruments sense ripples
caused by
winds near the ocean's surface, from which scientists can
compute the winds' speed and direction. The
200-kilogram (441-pound) SeaWinds instrument will be
launched aboard the
Adeos II satellite by a Japanese H-IIA
rocket. The satellite will circle
Earth every 101 minutes at
an altitude of 803 kilometers (499 miles). The
SeaWinds
instrument will make approximately 400,000 measurements every
day. SeaWinds
is managed for NASA's Office of Earth Science,
Washington, by JPL, which
developed the instrument and
performs instrument operations and science-data
processing,
archiving and distribution. The Japanese Space Agency
provided
the Adeos II spacecraft, H-IIA launch vehicle,
mission operations and the
Japanese ground network. NOAA
provides near-real-time data processing and
distribution for
SeaWinds operational data users. Back
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