Rocket blasts off from Florida with military communications satellite

[Buster's Uncle]

Rocket blasts off from Florida with military communications satellite
Reuters
Irene Klotz 5 hours ago


CAPE CANAVERAL, Florida (Reuters) - An Atlas 5 rocket blasted off from Cape Canaveral Air Force Station on Friday carrying a sophisticated communications satellite designed to provide voice and data services for U.S. military forces around the world.

The 206-foot (63-meter) tall rocket, built and operated by United Launch Alliance, a partnership of Lockheed Martin and Boeing, lifted off at 9 a.m. EDT (1300 GMT) from a seaside launch pad just south of the Kennedy Space Center.

Perched on top of the booster was the second satellite in the U.S. Navy's Mobile User Objective System, or MUOS, network. The satellites, built by Lockheed Martin, are intended to augment and eventually replace the Navy's existing Ultra High Frequency satellites.

Those UHF spacecraft provide 2.4 kilobytes per second of digital voice only. MUOS spacecraft provide 348 kilobytes per second and adds data transmission capability.

The network, which will include four operational spacecraft and one on-orbit spare, is intended to bring 3G-cellular technology to ships at sea, submarines, aircraft, land vehicles and troops in the field.

"You can think of the satellites as the cell towers in the sky," Lockheed Martin vice president Iris Bombelyn told reporters during a prelaunch conference call. "That's a really good way to think of how the system works."

Weighing in at nearly 15,000 pounds (6,804 kg), MUOS satellites are the heaviest payloads to have flown on Atlas 5 rockets, which are outfitted with five strap-on solid fuel boosters to accommodate the load.

The first MUOS satellite was launched in 2012. MUOS 3 is targeted to launch in 2014, followed by MUOS 4 in 2015 and MUOS 5 after that.

The new satellite will spend about eight days adjusting its orbit so that it circles about 22,300 miles above Earth. It will then unfurl its solar panel wings and deploy two antennas to begin on-orbit checkouts prior to being put into service sometime next year.

http://news.yahoo.com/rocket-blasts-off-florida-military-communications-satellite-154723317.html

[Geo]

Ah, they're in geosynchronous orbit. Quite a bit of overlap if 4 active ones are used.

[Buster's Uncle]

Planned redundancy, I'd guess.

[Geo]

Dunno, that's the job for the fifth one IMO.
Either way, these sats must have a propulsion unit with a nice amount of Delta-V. If one drops out, the armed forces must be able to shuffle them around to have total surface coverage again.

[Buster's Uncle]

US Navy Launches Next-Generation Tactical Satellite
SPACE.com
Mike Wall July 19, 2013  Science, Social Science, & HumanitiesTechnology & Electronics
 

The US Navy’s second Mobile User Objective System (MUOS-2) satellite launched from Cape Canaveral

The United States Navy successfully launched a huge communications satellite today (July 19), adding the second piece to a constellation that should provide a big boost to American troops.

The Mobile User Objective System-2 (MUOS-2) satellite blasted off from Florida's Cape Canaveral Air Force Station at 9:00 a.m. EDT (1300 GMT) today, riding to geostationay orbit atop a United Launch Alliance Atlas 5 rocket.

The 7.5-ton MUOS-2 — the heaviest payload ever lofted by an Atlas 5 — will help relay communications to forces on the ground from its perch 22,236 miles (35,785 kilometers) above the equator.

The MUOS network will eventually field a total of five spacecraft, with four core satellites and one orbiting spare.

"The MUOS constellation will ultimately replace the current UHF SATCOM system, providing military users with 10 times more communications capacity over existing systems, including simultaneous voice (full-duplex) and data, leveraging 3G mobile communications technology," United Launch Alliance officials wrote in a preview of today's launch.

MUOS-1 launched in February 2012. MUOS-3 is tentatively slated to lift off next summer, with MUOS-4 likely following about 12 months after that.

Lockheed Martin won a $2.1 billion contract from the Navy to build MUOS-1, MUOS-2 and associated ground control architecture back in September 2004. The Navy later exercised an option to build three more MUOS spacecraft.

http://news.yahoo.com/us-navy-launches-next-generation-tactical-satellite-175734029.html

I suppose the overlap would increase the resolution and/or reception...

[Geo]

Good point.
OTOH, wonder why they launch all five already, instead of keeping the spare one on the ground until one effectively malfunctions. It sounds much easier to launch the spare directly to the required position then shuffling around afterwards. Budget reasons?

[Buster's Uncle]

A difference of hours positioning the spare v. days/weeks, I should think.  Military stuff happens fast.