ADVANCED
COMMUNICATIONS SATELLITE SOARS INTO NIGHT SKY
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Launch
of the Tracking and Data Relay Satellite-J
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Courtesy:
NASA
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NASA's
third Tracking and Data Relay Satellite-J, TDRS-J, lifted
off from Cape Canaveral Air Force Station, Fla. at 9:42 p.m.
EST aboard an Atlas IIA rocket. Spacecraft separation from
the Centaur stage occurred at 10:12 p.m. Boeing controllers
made initial contact with TDRS-J at 10:41 p.m. EST as the
spacecraft passed over NASA's ground station in Canberra Australia.
"We
couldn't be more pleased with this evening's launch,"
said Robert Jenkens Jr., TDRS Project Manager at NASA Goddard
Space Flight Center in Greenbelt, MD. "Controllers have
already made contact with TDRS-J and all seems well. My congratulations
to everyone who helped make this launch a success."
During
the next eight days, a series of orbit raising maneuvers will
boost the 7,039-pound (3,196-kilogram) satellite into a geosynchronous
orbit 22,300 miles above the Earth's equator.
Boeing
Satellite Systems of El Segundo, Calif., which built the trio
of enhanced satellites for NASA under a fixed-price contract,
will command TDRS-J through completion of transfer orbit maneuvers,
appendage deployments, acquisition of Earth pointing in geostationary
orbit and pre-acceptance testing using NASA's Deep Space Network.
TDRS-J
will provide users with improved multiple access, S-band single
access, as well as a new Ka-band service. This second generation
TDRS will help replenish the original six TDRS, which have
provided reliable communications support to the Space Shuttle
and numerous Earth-orbiting science missions since 1983.
THIRD
ADVANCED COMMUNICATIONS SATELLITE TO LINK US WITH SPACE-BASED
RESEARCH MISSIONS
NASA's latest
Tracking and Data Relay Satellite, TDRS-J, will be able to transfer data at rates
5,000 times faster than the average 56K computer modem, and support Space Shuttle
missions with high-resolution digital television. TDRS-J is scheduled to launch
December xx aboard an Atlas IIA rocket from Cape Canaveral Air Force Station,
Fla. at the beginning of a 40-minute launch window which opens at 10:xx p.m. EST. TDRS-J
is the third in a series of three advanced satellites that will provide researchers
with unprecedented images from several NASA missions. "This
state-of-the-art communications system will support NASA's overall mission by
helping us better understand and protect our home planet, explore the universe,
search for life, and inspire the next generation of explorers," said Robert
Jenkens Jr., TDRS Project Manager at NASA' Goddard Space Flight Center, Greenbelt,
Md.
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| The
Tracking and Data Relay Satellite-J | | |
The
enormous amount of scientific data, flowing through the TDRS fleet, benefits people
everywhere. TDRS supports several NASA Earth and space science missions, such
as the Hubble Space Telescope, which helps scientists explore the birth and death
of stars, Landsat 7, which helps farmers and urban planners wisely use the Earth's
valuable natural resources, and the Tropical Rainfall Measuring Mission, which
provides scientists with accurate rainfall measurement maps. TDRS' advanced capabilities
make all of this possible. In
addition to providing existing S-band Single Access and Ku-band Single Access
capabilities, TDRS-J will provide users with the following new services: Ka-band
Single Access: This new higher-frequency service, which operates from 22.5 to
27.5 Gigahertz and increases data rate capabilities to 800 megabits per second,
will provide communications with future missions requiring higher bandwidths such
as multi-spectral instruments for Earth science applications. This frequency also
is less susceptible to interference from our increasingly busy radio environment.
Two 15-foot-diameter flexible graphite mesh antenna reflectors provide the accurate
and steerable response for the Ka-band operating frequency. The reflectors, which
remain folded during launch, 'spring back' to their original cupped circular shape
once on orbit. Multiple
Access: The system is capable of receiving signals from five user spacecraft simultaneously
at rates up to 3 megabits per second, while transmitting to a single user at up
to 300 kilobits per second. Operates using a phased-array antenna in the 2.0 to
2.3 GHz range. Transfer
orbit operations, which are scheduled to occur during a two-week period following
the launch, will boost the 7,042-pound (3,197-kilogram) spacecraft to a geosynchronous
orbit 22,300 miles above the Earth's equator. Fully
deployed, the satellite will measure approximately 69 feet long (21 meters) by
4e feet (13 meters) wide. The satellite's silicon celled solar arrays will generate
2,300 watts of on-orbit power. A nickel-hydrogen battery aboard TDRS-J will supply
power during solar eclipses. The
TDRS replenishment program cost approximately $800 million and includes the three
satellites, associated expendable launch vehicles, upgrades to the White Sands
Complex and NASA program costs. Boeing
Satellite Systems of El Segundo, Calif., designed, built and tested TDRS-H, I
and J for NASA under a fixed-price contract. Back
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| Boeing
satellite technicians assemble the solar wings to NASA's second Tracking and Data
Relay Satellite (TDRS-I) at the Integration and Test Complex in El Segundo, Calif. |
| Image
courtesy of Boeing Satellite Systems | The
second generation TDRS are equipped with innovative folding antennas. NASA's requirements
called for reflectors with a large surface area, yet low weight. Each pair of
15-foot-diameter, flexible graphite mesh antenna reflectors fold easily inside
the fairing for launch, then spring back into their original cupped circular shape
once on orbit. When fully deployed, these satellites measures 68 feet, 10 inches
in length and 43 feet, five inches in width. Back
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