SPACEFLIGHT NOW
Posted: July 19, 2013
Leaping off the launch pad Friday in its most powerful arrangement to boost its heaviest payload into orbit, a United Launch Alliance Atlas 5 rocket successfully deployed the second in a series of sophisticated spacecraft to grow the U.S. Navy's new mobile communications network that will span the globe.
Credit: Walter Scriptunas / Spaceflight Now
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The energetic rocket, created by attaching five strap-on solid-fuel motors to the kerosene-fed main stage to deliver two-and-a-half million pounds of thrust, launched from Cape Canaveral at 9:00 a.m. EDT.
The 206-foot-tall rocket blasted off after its overnight countdown progressed smoothly and a brief hold for upper level wind conditions to clear.
It begins a string of five national security launches that the Air Force will perform with United Launch Alliance in a three-month span through October, using both Atlas and Delta 4 rockets from the Cape and Vandenberg Air Force in California. The future flights will deploy two Air Force communications spacecraft, a massive spy satellite for the National Reconnaissance Office and a new GPS bird.
The surge began in successful fashion with the Navy's Mobile User Objective System satellite No. 2, taking the next step to construct a worldwide communications system using 3G-cellular technology for ships, submarines, aircraft, land vehicles and terminals in the hands of troops.
"When the constellation is fully populated, users will be able to speak to any other user on the globe," said Navy Capt. Paul Ghyzel, manager of the Satellite Communications Program Office.
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"Today, the traditional (satellite communications) system, two users who want to communicate with each other need to be underneath the same satellite. MUOS changes that.
"So with the second satellite being launched and checked out and put into operations, we'll continue our coverage (expansion) of the globe and basically double it because we will have two satellites on-orbit working towards our ultimate objective of true global coverage once we get the remaining satellites on-orbit. That's really the big coverage gain (with Friday's launch).
"From a technical standpoint, with two satellites on-orbit it allows us to verify and validate how the system works. As we test out the system, we'll be communicating with a user that's underneath satellite No. 1, the traffic, both voice and data traffic will be routed through the ground network and routed up through the second satellite in several of our test scenarios to be sent to a user or multiple users that are underneath the footprint of the second satellite."
MUOS 1 was launched in February 2012 and put into operation by year's end. MUOS 2 will complete its post-launch orbit shaping in about 8 days, then deploy its solar arrays and twin umbrella-like antenna reflectors to achieve the "flight configuration" about 12 days after launch.
Then begins several months of satellite system and payload testing before builder Lockheed Martin hands over the craft to the government for additional checks in advance of setting it operational in early 2014.
From its eventual spot in geosynchronous orbit, a parking spot 22,300 miles up, the expansive footprint of MUOS 2 will cover nearly a third of the planet. However, what geographical area of the globe the craft will cover hasn't been finalized yet, officials said.
MUOS serves a dual-provider of both voice traffic currently routed by the Navy's existing generation, albeit aging, Ultra High Frequency Follow-On spacecraft, but it also creates a new era of mobile communications built around 3G cellular technology to relay narrowband tactical information such as calls, data messaging, file transfers and email on rates of up to 384 Kilobits per second.
An artist's concept of MUOS. Credit: Lockheed Martin
"One of the way we frequently describe the new capabilities that MUOS brings is think of a cellphone," Ghyzel said.
"The architecture that we've built with the satellite constellation and with the global ground network, the satellite is the celltower. Anybody that is using a radio that is capable of communicating with MUOS, when they speak their transmission is picked up by the satellite and then routed like a cellular system would route to wherever it needs to be to talk to the guy on the other end.
"So if you are driving down the interstate and you walk to talk to a guy one county over, you may be using the same tower. For Bob to talk to Jim.
"But if Bob is in Florida and wants to talk to his wife in Seattle, he can pick up a cellphone, the tower next to the interstate he is driving on is going to pick up that call, but then it is going to go through a fiber optic network to get to a celltower that is closest to his wife in Seattle and that tower is going to send that call to her cellphone.
"Much like for us in MUOS, if you got somebody that's in Hawaii that needs to talk to a ship that's 200 miles off Hawaii, that traffic is going to go through the satellite that is over the Pacific.
"But if that ship commander needs to talk to somebody that is in Afghanistan, then they are going to transmit over MUOS, the satellite over the Pacific is going to up that transmission, but (it is) then routed through the rest of the MUOS network to the satellite that's going to be over the Indian Ocean, eventually, and then down into Afghanistan.
"You can think of the satellites as the celltowers in the sky. That's a really good way to think of how the system works."
MUOS 3 is expected to launch in about 12 months, followed by MUOS 4 in the summer of 2015. The constellation will feature four primary satellites and one on-orbit spare, all designed and built as clones of each other.
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