NASA's next-generation orbital tracking and communications
network has been completed, with the sixth and final Tracking and Data Relay
Satellite (TDRS) blasted into orbit on Friday. The Boeing-built TDRS-M lifted
off from Cape Canaveral Air Force Station in Florida atop a United Launch
Alliance (ULA) Atlas V rocket. It is reported to be in good health and will
enter service next year after a four-month checkout.
In the early decades of the Space Age, communications and
tracking of important missions was entirely dependent on ground stations. This
meant that spacecraft like Skylab, launched in 1973, were only in contact with
mission control during the fleeting moments when they were above the horizons
of various tracking stations distributed around the world.
Established in 1973, the TDRS project was introduced to
provide NASA with a Space Network that uses a constellation of orbital
satellites to provide continuous tracking and high-data-rate communications
with the International Space Station, the Hubble Space Telescope, launch
vehicles, and other spacecraft in low-Earth orbit.
The first satellite, TDRS-1, was launched in 1983. TDRS-M
and its five counterparts are the latest in the series, the first of which was
sent up in 2000.
"The TDRS fleet is a critical connection delivering
science and human spaceflight data to those who can use it here on Earth,"
says Dave Littmann, the TDRS project manager at NASA's Goddard Space Flight
Center. "TDRS-M will expand the capabilities and extend the lifespan of
the Space Network, allowing us to continue receiving and transmitting mission
data well into the next decade."
