Continuing
20 years of building and maintaining the Global Positioning System, the
workhorse Delta 2 rocket this morning successfully launched another satellite
for the navigation network known the world over.
The
12-story booster rumbled out of Cape Canaveral's pad 17A at 4:34 a.m. EDT,
shaking the sleeping Space Coast and dashing into the predawn skies.
Burning and
separating its nine strap-on solid motors as designed, the kerosene-powered
first stage pushed the rocket 60 miles up. The hypergolic second stage then
assumed control, igniting its engine and jettisoning the nose cone shrouding
the GPS 2R-20 satellite payload.
The rocket
eased into an initial orbit over the central Atlantic Ocean and began a
peaceful coast through space to reach the skies over the western Pacific. In
view of the tracking station on Guam, the second stage fired briefly to raise
the orbit and then released the solid-fuel third stage to propel the new GPS
satellite into its prescribed orbit.
Launch
managers back at the Cape anxiously waited for the rocket to complete its
programmed sequence, finally receiving the news of a successful deployment of
the GPS 2R-20 spacecraft about 68 minutes after liftoff.
"Congratulations
to the entire team for their hard work and dedication to the mission,"
said Brig. Gen. Edward L. Bolton Jr., 45th Space Wing commander at the Cape. "The launch of another GPS satellite provides our warfighters a system on which
they can depend to complete their missions successfully."
"It's
great to see months of hard work by the team pay off in the form of a
successful launch," added 1st Lt. Jonathan McGuire, the Delta 2 booster
operations controller. "It's been a long wait, but knowing that this
satellite will be directly supporting the war on terrorism was a reward worth
waiting for."
Out with
the old, in with the new
The GPS
2R-20 spacecraft will rejuvenate one of the navigation constellation's
positions, while also conducting critical tests of a new signal to be fielded
by follow-on satellites.
The craft
will replace the aging GPS 2A-27 satellite launched in September 1996. Now well
past its design life, ground controllers plan to move the old satellite into a
backup role.
The new GPS
2R-20 spacecraft will take over the Plane B, Slot 2 location of the navigation
network, considered one of the primary positions in the constellation that is
divided into six orbital groupings with multiple satellites flying in each.
GPS
satellites fly about 11,000 miles above the planet and emit continuous
navigation signals that allow users to find their precise position in latitude,
longitude and altitude and determine time. Originally built for the U.S. military, the GPS
service has spread across the world as an indispensable commercial utility.
"GPS
contributes vital capabilities to our nation's military operations, global
information infrastructure, emergency response, transportation and
telecommunication industries, the international economy and everyday life. Our
commitment is to ensure this emerging capability continues to deliver precise
positioning, navigation and timing service to users around the globe,"
said Mike Dunn, technical director of the Space and Missile Systems Center's Global Positioning Systems Wing.
The
satellite is the seventh in a series of eight equipped with modernized
features. The upgraded satellites transmit additional signals and offer
improvements aimed at greater accuracy, tougher resistance to interference and
enhanced performance for users around the world.
The new
civilian signal removes navigation errors caused by the Earth's ionosphere. The
military advancements will provide a more robust jam-resistant signal and
enable better targeting of GPS-guided weapons in hostile environments.
"Every
year we have made the GPS signal better, every year the accuracy of the system
has improved," said Gen. Robert Kehler, commander of Air Force Space
Command. "And that is what is going to continue to happen."
The
satellite is the 20th built by Lockheed Martin, but the two-ton craft is unique
because it carries a special demonstration package to test a new civil signal,
called L5, planned for the aviation community.
"This
is a demonstration of that signal," said Tom Nagle, program manager of
civil applications at the Transportation Department. "It is a key part of
all aviation planning for the next generation aviation systems."
Taking
advantage of the satellite's auxiliary payload accommodations and modifying
available parts in inventory, Lockheed Martin was able to add the new L5 signal
in a straight-forward fashion. Two boxes were put on the spacecraft, increasing
its weight by about 40 pounds.
"Just
using the capabilities of the vehicle, some of the spare parts that we had on
the modernization program, we were able to modify them to add the
demonstration," said Dave Podlesney, a GPS executive at Lockheed Martin.
The Air
Force needs the satellite in orbit and the new frequency demonstrated before an
International Telecommunications Union deadline in late August.
The
in-space testing of the L5 system on this satellite will verify the new
frequency doesn't impact the other signals being broadcast. "So that's an
important way to the pave the path for future use," Dunn said.
The next
generation GPS 2F satellites, being built by Boeing, will transmit the new L5
signal when they begin launching over the next few years.
"The
signal has higher power than the other signals that we have, which allows more
protection from interference sources. Also, the signal is in a band that is
protected by the aviation community," Nagle said.
Delays in
the GPS 2F program prompted the Air Force to have Lockheed Martin add the
demonstration to this satellite to ensure the U.S. government could secure the
rights to the frequency.
Air
Force's use of the Delta 2 nearing end
Flying much
the same mission as its inaugural flight two decades ago that deployed a GPS
satellite, today's Delta 2 launch occurred just a month after the rocket
celebrated its 20th anniversary. This latest success is the 47th GPS spacecraft
put into orbit by the venerable rocket.
"One
third of the 140 successful Delta 2 launches have been dedicated to GPS
satellites. The ULA Delta team is extremely proud of the role we've played in
launching this incredible satellite constellation," said Jim Sponnick,
United Launch Alliance's vice president of the Delta Product Line.
"During
the past two decades, GPS has changed how people navigate around their
neighborhoods and around the globe. GPS has also greatly improved military
operations as well as numerous maritime, aircraft and business operations
worldwide."
Born in the
late 1980s during an overhaul of U.S. space policy following the Challenger
accident, the Delta 2 was conceived as part of the nation's desire to shift its
dependence away from the space shuttle.
New
expendable boosters were ordered to launch satellites, and the Air Force's
Global Positioning System would become the anchor customer for the Delta 2.
"The
Delta 2 program was started back in 1987. It was one of the programs that the
Air Force started after the Challenger accident, and then the first launch was
in 1989. So this launch vehicle has had a long history of successful launches
and service to the country, both military and civil users," said John
Wagner, technical director of the Launch and Range Systems Wing at the Space
and Missile Systems Center.
"There's
a lot of us, including myself, that were part of the original Delta 2 program.
I had the honor being part of it back in 1989 when I was assigned at the
Pentagon, and worked it when I was assigned at Vandenberg. There is a lot of
pride that this program has been a huge success for the Air Force. It's done
everything that we've asked it to do, plus more, and it's helped carry us into
the 21st century."
The Air
Force has just one more Delta 2 rocket left to fly. Its stages sit in hangars
at Cape Canaveral awaiting on-pad assembly to begin May 27, said Lt. Col. Erik
Bowman, commander of the 1st Space Launch Squadron.
Liftoff is
planned for August 21 to loft the final Block 2R satellite in the GPS
replenishment program. It's also the final scheduled use of pad 17A.
The GPS
2R-21 satellite was delivered to the launch site in January 2008. The craft
will be brought out of storage and begin its pre-flight processing campaign in
June, said Lt. Col. John Wagner, commander of the 45th Launch Support Squadron
at the Cape.
Although
the Delta 2 proved to be highly reliable for medium-size satellites, the Air
Force is transitioning
to newer rockets -- the larger Atlas 5 and Delta 4 vehicles -- that are
meant to be versatile in launching a range of different payloads.
"While
we'll be sorry to see it go, obviously, it's been a bridge toward Delta
4," Wagner said.
A Delta 4
rocket, for instance, is slated to launch first GPS 2F satellite at the end of
2009.
United
Launch Alliance has eight other Delta 2 launches for NASA and commercial
customers planned through 2011. The company also has five rockets available to
sell.
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