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EVERYTHING
IS RIGHT ON 'TIMED' WITH NEW SOLAR SCIENCE SATELLITE (11 February 2002) With
its post-launch engineering checkouts complete, NASA's TIMED (Thermosphere, Ionosphere,
Mesosphere, Energetics and Dynamics) spacecraft is now globally studying one of
Earth's final atmospheric frontiers. During
its planned two-year mission, TIMED will study the basic structure of the MLTI
(Mesosphere and Lower Thermosphere/ Ionosphere) - a mysterious region of space
located about 40-110 miles above the Earth. TIMED will examine the MLTI's chemistry
and flow of energy to and from this layer of the atmosphere. Scientists will analyze
how the region affects, and is affected by, the lower atmosphere, how it influences
the space near Earth occupied by low-Earth orbiting satellites, and how events
on the Sun affect the MLTI. "We're
very excited that our science mission is underway," says Dr. Sam Yee, TIMED
project scientist and the mission's science team leader at The Johns Hopkins University
Applied Physics Laboratory in Laurel, Md. "TIMED's observations will provide
us with the first-ever global picture of this critical region of our atmosphere,
which will allow scientists to form a baseline for future studies of this area.
Orbiting
from a unique vantage point above the MLTI, TIMED will use its remote sensing
instruments, together with a network of ground-based observation sites to obtain
an unprecedented set of comprehensive global measurements of the region. TIMED
is the first of several Solar Terrestrial Probes (STP) NASA plans to launch. STP
missions, which are managed by Goddard, focus mainly on responses to two goals
of the Sun-Earth Connection theme: (1) How and why does the Sun vary; and (2)
How do the Earth and planets respond? Goddard
manages the TIMED mission for the Office of Space Science in Washington, D.C.
The Johns Hopkins University Applied Physics Laboratory designed, built and operates
TIMED, and also manages the mission's Science Data Center for NASA.
The
TIMED Mission
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1 | | The
TIMED spacecraft being launched from Vandenberg Air Force Base, CA. |
After
a successful launch from Vandenberg AFB, Calif. on Dec. 7, 2001, the TIMED spacecraft
was placed into an excellent orbit. TIMED Mission Operations personnel at The
Johns Hopkins University Applied Physics Laboratory in Laurel, Md. are proceeding
with a routine, 30-day engineering checkout of the spacecraft and its four instruments,
which have been turned on, tested and are operating successfully. Once the 30-day
checkout period is completed, the TIMED spacecraft can be declared operational
and science operations will begin.
TIMED
SPACECRAFT LAUNCHES, RELAYS FIRST SIGNAL TO CONTROLLERS ON EARTH A
new NASA spacecraft that will study the effects of the sun and human-induced activities
on the least explored and understood region of Earth's atmosphere soared into
a clear early morning California sky today. The
TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) spacecraft
lifted off from the Western Range of Vandenberg Air Force Base, Calif., aboard
a Delta II rocket at 10:07 a.m. EST. Spacecraft separation from the Delta II rocket's
second stage motor occurred at 12:13 p.m. EST, inserting TIMED into a 388-mile
(625-kilometer) circular orbit around the Earth. At
1:10 p.m. EST, controllers at the TIMED Mission Operations Center of The Johns
Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., made contact
with TIMED as it passed over a ground station in Kiruna, Sweden, confirming that
solar arrays deployed, providing power to the spacecraft. "Three
hours is a long time to hold your breath," said TIMED Project Manager Bruce
Campbell at NASA's Goddard Space Flight Center in Greenbelt, Md., "and we're
pleased with the way things look right now." Solar
array deployment occurred immediately following spacecraft separation. During
the next 30 days or so, controllers will turn the four instruments on and check
them out prior to starting science observations. TIMED should be ready to begin
its global study of the MLTI region in mid-January 2002. "TIMED
will provide a very important benchmark for future studies of both natural and
human-induced changes to the Earth's atmosphere, said Sam Yee, TIMED project scientist
at APL. "TIMED's measurements will help scientists understand how the region's
composition is affected by contaminants that are released into Earth's atmosphere
and by solar energy entering this region." The
TIMED mission is sponsored by NASA's Office of Space Science in Washington, D.C.,
and managed by the Solar Terrestrial Probes Program Office at Goddard. APL designed,
built and will operate the TIMED spacecraft and lead the science effort for NASA. Back
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2 | | The
TIMED spacecraft being checked at Vandenberg Air Force Base, CA. |
TIMED:
A NASA Mission to Explore One Last Frontier There
is a layer of our atmosphere that is the gateway betwen Earth's environment and
space, which we know very little about. Ground-based instruments can only observe
small sections, the region is too high for balloons to reach, and sounding rockets
only provide a brief snapshot. NASA
will soon explore this region called the Mesosphere and Lower Thermosphere/ Ionosphere,
or MLTI, with the launch of the Thermosphere-Ionosphere-Mesosphere-Energetics
and Dynamics (TIMED) satellite, scheduled for December 7 from Vandenberg Air Force
Base,Calif.. This
mission will be the first to obtain "global" pictures of this unique
region, where energetic solar radiation is absorbed and intense electrical currents
flow producing beautiful auroras. With the newest remote-sensing technology, the
spacecraft's instrument suite will work with a worldwide network of ground-based
observation sites, to obtain an unprecedented set of "global" measurements:
temperature, pressure, winds, chemical composition, and energy inputs and outputs.
For
centuries, scientists have known that Earth's natural environment is greatly impacted
by solar energy, which strikes the Earth from a constantly changing sun. Human
activities also play a role, and some scientists believe the MLTI region could
be an early indicator of global change. What happens here also affects satellite
tracking, spacecraft lifetimes, and the re-entry of piloted vehicles. Thus, with
a society increasingly dependent upon satellite technology and communications,
it becomes vital that we gain a better understanding of this critical region.
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3 | | TIMED
spacecraft inside DPAF and ready for flight. | The
TIMED spacecraft will be boosted into its 625-kilometer circular orbit by a Boeing
Delta II rocket. The 1,320 lb. (600 kilogram) TIMED spacecraft will also have
solar arrays that extend beyond the body of the spacecraft to capture and convert
energy from the Sun into electricity. TIMED's
distributed data management system, the Mission Data Center (part of the Mission
Operations Center) will be responsible for down-linking raw data from the satellite
and then sending it, via direct links, to processors at each of the remote Payload
Operations Centers. Data collected during each 90-minute orbit will be downloaded
once a day and rapidly distributed, via the Internet. The centers will process
their instrument's raw data and turn it into data products that can be used by
the public, and scientific and educational communities, and the general public. CLICK
ON LINKS FOR QUICKTIME ANIMATIONS. TIMED
Animation Quicktime - The TIMED satellite will be the first mission to obtain
global pictures of the MLTI region. TIMED's
Connection to the Sun Quicktime
Earth's atmosphere shields us from the
sun, but also warms the planet. TIMED will explore one of the last frontiers -
where the sun's energy is first deposited and absorbed into the Earth's atmosphere. TIMED's
Deployment Quicktime
The TIMED spacecraft will be boosted into its 625-kilometer
circular orbit around the Earth aboard a Delta II launch vehicle. What
does TIMED stand for? TIMED
is an acronym for Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics.
The TIMED mission will study a region of Earth's atmosphere located approximately
40-110 miles (60-180 kilometers) above the Earth's surface — the Mesosphere
and Lower Thermosphere/Ionosphere, or MLTI.
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4 | | TIMED
spacecraft in the thermal vacuum test at the Goddard Space Flight Center, Greenbelt,
MD. | What
will TIMED accomplish that other spacecraft have not? TIMED
will be the first mission to conduct a comprehensive global study of the MLTI
region, including its basic structure and thermal balance, how the mesosphere
is coupled to the thermosphere/ionosphere, how the MLTI region is coupled to space
and the lower atmosphere below, and how energy is transported vertically and horizontally
through this region. The TIMED mission will establish a baselineagainst which
future studies of changes within this region can be compared and analyzed.
How does TIMED fit into NASA's overall science program? The
Sun-Earth Connection (SEC) is one of four principal science themes around which
missions within NASA's Office of Space Science are organized. The Sun-Earth Connection
focuses mostly on explaining the physical processes that link the sun and the
Earth. TIMED is the first mission within the Solar Terrestrial Probes Program
(under the SEC theme). TIMED will investigate one of the Sun-Earth Connection's
quests: How does the Earth's upper atmosphere respond to solar inputs? The Solar
Terrestrial Probes Program offers a continuous sequence of flexible, cost-capped
missions designed to systematically study the Sun-Earth system. Solar Terrestrial
Probes will focus on studying the sun and the Earth as an integrated system using
a blend of in situ and remote-sensing observations, often from multiple platforms.
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5 | | Testing
the arrays on the TIMED spacecraft. | Why
is it important to study the MLTI region? This
region is where the sun's energy is first deposited into Earth's environment.
The sun's energy can have profound effects on Earth's upper atmospheric regions,
particularly during the peak of the sun's 11-year solar cycle when the greatest
amounts of its energy are being released. TIMED is focused on understanding and
characterizing exactly how the sun interacts with the Earth's environment. It
will allow scientists to establish the first-ever baseline of the MLTI region
against which future studies of changes within this region can be compared and
analyzed.
Why have studies of this region been limited? A
comprehensive global study of the entire MLTI region has never before been accomplished
for several reasons. Ground-based instruments can only see a small portion of
the upper atmosphere located over an observation site. It also is too high for
balloons to reach, and sounding rockets (rockets that fly into the upper atmosphere
for just a few minutes before falling back down) can only provide a brief snapshot
of the MLTI region's activity near the rocket. How
will TIMED provide the first-ever global picture of the MLTI region? The
TIMED spacecraft will observe the MLTI region and its basic structure from the
spacecraft's 388-mile (625-kilometer) circular orbit around the Earth. Employing
advances in remote-sensing technology, the spacecraft's instrument suite will
work with a worldwide network of ground-based observation sites to collect information
that scientists will use to test their current understanding of processes that
change the winds and composition in this part of the atmosphere, and determine
how energy is absorbed, emitted and transported within the MLTI region. How
many and what types of instruments are onboard the spacecraft? TIMED's
payload consists of four instruments. The Global Ultraviolet Imager (GUVI) is
an ultroviolet spectrograph that measures the composition and temperature profiles
of the MLTI region, as well as its auroral energy inputs. The Solar Extreme Ultraviolet
Experiment (SEE) is comprised of a spectrometer and a suite of photometers that
measure the solar soft X-ray, extreme-ultraviolet and far-ultraviolet radiation
whichis deposited into the MLTI. The TIMED Doppler Interferometer (TIDI) measures
the wind and temperature profiles of the MLTI region. A multichannel radiometer
called SABER (Sounding of the Atmosphere using Broadband Emission Radiometry)
measures the pressure, temperature, key gases in the oxygen and hydrogen families,
infrared cooling, and effects of solar and chemical heating of the MLTI. Who
will have access to TIMED data and how will it be distributed? How quickly will
data be available? Data
obtained during the TIMED mission will be available to the public (from TIMED's
Web site at: www.timed.jhuapl.edu) within 54 hours of receiving the data on the
ground.
How
long will the mission last? The
TIMED spacecraft will collect data for two years. TIMED's Mission Operations and
Science Data centers, located at The Johns Hopkins University Applied Physics
Laboratory, Laurel, Md., will provide an additional two years of data analysis. What
are the mission costs? The
total cost for TIMED is about $193 million for the spacecraft, its instrument
payload and the launch vehicle. An additional $42 million is reserved for ground
operations, mission operations and data analysis.
What are the key
characteristics of the spacecraft? Mass
1,294 pounds (587 kilograms)
Dimensions 8.93 feet (2.72 meters ) high
5.29 feet (1.61 meters) wide (launch configuration)
38.5 feet (11.73 meters)
wide (solar arrays deployed)
3.93 feet (1.2 meters) deep
Power Comsumption
406 watts per orbit
Data Downlink 4 megabits per second
Memory 5 gigabits
Attitude
Control Within .5 degrees
Knowledge Within .03 degrees
Who
is sponsoring and managing the mission? Who is building the spacecraft and its
instruments? TIMED
is sponsored by Office of Space Science in Washington, D.C., and managed by the
Solar Terrestrial Probes Program Office at NASA's Goddard Space Flight Center
in Greenbelt, Md. The Johns Hopkins University Applied Physics Laboratory in Laurel,
Md., designed, built and will operate the spacecraft and lead the project's science
effort for NASA. The
instrument teams include: GUVI:
•
The Aerospace Corporation, El Segundo, Calif.
• The Johns Hopkins University
Applied Physics Laboratory, Laurel, Md.
• University of Alaska's Geophysical
Institute, Fairbanks, Ala.
• Southwest Research Institute, San Antonio,
Texas
• Naval Research Laboratory's E.O. Hulburt Center for Space Research,
Washington, D.C.
• Computational Physics, Inc., Fairfax, Va.
•
University of Colorado's Cooperative Institute for Research in Environmental Sciences,
Boulder, Colo. SABER: •
Hampton University, Hampton, Va.
• NASA Langley Research Center, Hampton,
Va.
• Utah State University, Logan, Utah
• G&A Technical
Software Inc., Hampton, Va.
• National Center for Atmospheric Research,
Boulder, Colo.
• National Oceanic and Atmospheric Administration's Aeronomy
Laboratory, Boulder, Colo.
• Astrophysical Institute of Andalucia (IAA),
Granada, Spain
• Air Force Research Laboratory, Hanscom Air Force Base,
Mass.
• Naval Research Laboratory, Washington, D.C.
• Stewart
Radiance Laboratory, Bedford, Mass.
• British Antarctic Survey, Cambridge,
England SEE:
•
University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder,
Colo.
• High Altitude Observatory at the National Center for Atmospheric
Research, Boulder, Colo.
• Hampton University, Hampton, Va.
•
Naval Research Laboratory, Washington, D.C.
• Federal Data Corporation
at the Jet Propulsion Laboratory, Pasadena, Calif. TIDI: •
National Center for Atmospheric Research, Boulder, Colo.
• University
of Michigan, Ann Arbor, Mich.
• National Oceanic and Atmospheric Administration's
Space Environment Center, Boulder, Colo.
• Hovemere Limited, Kent, U.K.
• University of California, Berkeley, Calif.
• High Altitude Observatory
at the National Center for Atmospheric Research, Boulder, Colo.
• CREES-York
University, Toronto, Canada
• Institute of Atmospheric Physics at the
Rostock University, Rostock, Germany
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