A powerful Atlas 5 rocket carrying a 15,000-pound Navy communications satellite streaked into space Tuesday, carrying the third of five relay stations planned for a $5 billion global network designed to handle high-speed mobile phone traffic as well as voice and data from older systems.
Lighting up the night sky, the 206-foot-tall Atlas 5's Russian-built RD-180 first-stage engine thundered to life at 8:04 p.m. EST (GMT-5) followed an instant later by ignition of five solid-fuel strap-on boosters.
Liftoff came 21 minutes late because of high winds aloft and radio interference with an Air Force Eastern Range system needed to send self-destruct commands in the event of a major launch failure. But the winds died down and engineers resolved the command interference issue, clearing the way for launch.
Generating a combined 2.7 million pounds of thrust -- the most liftoff power of any current U.S. rocket -- the Atlas quickly climbed away from its seaside launch pad atop a brilliant torrent of fire, smoothly accelerating as it consumed its load of propellants and shed weight. The booster exceeded the speed of sound in just over 30 seconds as it arced away to the east over the Atlantic Ocean.
The five strap-on boosters fell away as expected just under two minutes after liftoff and the Atlas first stage followed suit two-and-a-half minutes later. The Centaur second stage continued the push to orbit under the power of a single hydrogen-fueled Aerojet Rocketdyne RL10C-1 engine generating nearly 23,000 pounds of thrust.
A second Centaur firing went well with a third planned nearly three hours after launch to put the heavyweight satellite into an initially elliptical "transfer" orbit with a high point, or apogee, of about 22,236 miles and a low point, or perigee, of around 2,370 miles.
If all goes well, the satellite's on-board propulsion system will be used over the next week or so to raise the perigee, putting MUOS-3 into a circular orbit 22,300 miles above the equator. At that "geosynchronous" altitude, satellites take 24 hours to complete one orbit and thus appear to hang stationary in the sky.
Another three days will be needed to unfurl the relay station's solar arrays and two main antennas. One of them, a 17-foot-wide gold mesh dish, will send and receive signals from ground terminals that currently send voice and data through older Ultra High Frequency Follow-On, or UHF, satellites. A much larger 46-foot-side antenna will provide the equivalent of 3G-class cellular network-type communications.
Built by Lockheed Martin, four MUOS satellites will form the core of an operational network with a fifth spacecraft serving as a spare. The new satellites eventually will replace the Navy's older UHF comsats.
A Lockheed Martin website described the new relay stations as "a next-generation narrowband tactical satellite communications system designed to significantly improve ground communications to U.S. forces on the move around the globe."
"MUOS will provide military users more communications capability over existing systems, including simultaneous voice, video and data -- similar to the capabilities experienced today with smart phones," the company said.
Navy Capt. Paul Ghyzel, manager of the Satellite Communications Program Office, said before the MUOS-2 launch last summer the new satellites operate like cell phone towers in space.
"Anybody (who) 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," he said.
The satellites can route calls directly between users or relay calls to other MUOS satellites to connect more widely separated users, operating much like cell phone towers do to link terrestrial phone calls.
"With MUOS, we've taken commercially available cell phone technology that I think we're all kind of familiar with in our daily lives, except that our cell towers are 22,000 miles above us on that satellite," Cmdr. Pete Sheehy said Tuesday. "By doing that, we've enabled a ten times increase in the number of users that we can accommodate, as well as things like adaptive power control that allows disadvantaged users or very mobile users the ability to very reliably maintain connections.
"In addition to that, if you think about the days when you had your old flip phone and all you used it for was voice and maybe a couple of texts, we've now allowed our users to connect to Navy and government classified networks, as well as unclassified networks and government phone systems, so it operates similar to smart phones in use today."
Tuesday's launch marked the first of 13 flights planned this year by ULA following 14 successful missions in 2014. It was the 52nd flight of an Atlas 5 since Lockheed Martin and Boeing joined forces to form ULA in 2002, the 200th overall for the Atlas Centaur rocket since flights began in 1962 and only the fifth to feature five strap-on boosters.