NASA is ready to launch the third advanced Tracking and
Data Relay Satellites, named TDRS-J, which will have the
ability to transfer data 5,000 times faster than a
computer’s 56K modem, transmit near real-time audio and
high-resolution digital video from Earth-orbiting spacecraft
and provide tracking services for expendable launch
vehicles.
TDRS-J is scheduled to launch Dec. 4 aboard an Atlas IIA
rocket from Cape Canaveral Air Force Station, Fla., at the
beginning of a 40-minute launch window, which opens at 9:42
p.m. EST.
The new trio of satellites joins forces with the original
TDRS constellation to support the Space Shuttle,
International Space Station, Hubble Space Telescope and a
host of other Earth-orbiting spacecraft.
“This state-of-the-art communications system will support
NASA’s mission by providing a communications backbone for
astronauts aboard the Shuttle and Space Station, as well as
relay vital data from several Earth and space science
missions,” said Robert Jenkens Jr., TDRS Project Manager at
NASA’s Goddard Space Flight Center, Greenbelt, Md.
TDRS-J features the following capabilities:
* S-band Single Access: Two 15-foot diameter steerable
antennas, used at the 2.0 to 2.3 GHz (gigahertz) band,
supply robust communications to user satellites with smaller
antennas and receive telemetry from expendable launch
vehicles during launch.
* Ku-band Single Access: The same two antennas, operating
from 13.7 to 15.0 GHz, provide higher bandwidth for user
satellites, provide high-resolution digital television for
Space Shuttle video communications and can quickly transfer
large volumes of data from tape or solid-state data
recorders aboard NASA scientific spacecraft.
* 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 for future missions requiring higher
bandwidths such as multi-spectral instruments for Earth
science applications.
* Multiple Access: This 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. The system operates
using a phased-array antenna in the 2.0 to 2.3 GHz range.
For two weeks following the launch, transfer orbit
operations will boost the 7,039-pound (3,196-kilogram)
satellite into a geosynchronous orbit 22,300 miles above the
Earth’s equator. Upon completion of on-orbit testing and
acceptance, TDRS-J will be renamed TDRS-10.
Fully deployed, the satellite measures approximately 69 feet
long (21 meters) by 43 feet (13 meters) wide. The
satellite’s silicon celled solar arrays will generate 2,300
watts of on-orbit power and a nickel-hydrogen battery will
supply power during solar eclipses.
The TDRS replenishment program cost approximately $800
million and includes three satellites, expendable launch
vehicles, upgrades to the White Sands Complex in Las Cruces,
N.M., and NASA program costs. Boeing Satellite Systems, El
Segundo, Calif., designed, built and tested TDRS-H, I and J
for NASA under a fixed-price contract.
Additional information about TDRS is available on the
Internet at:
http://tdrs.gsfc.nasa.gov/Tdrsproject/
http://nmsp.gsfc.nasa.gov/tdrss/tdrsshome.html