Looking towards launch next week to begin dramatically improving the capacity for U.S. military mobile communications, a new breed of satellite was hauled to the towering Atlas 5 rocket assembly building today for mounting atop the powerful booster.

File image of Atlas payload arriving at the VIF. Credit: NASA-KSC

The Navy's first Mobile User Objective System satellite, dubbed MUOS 1, is scheduled for blastoff next Thursday, Feb. 16, at sunset from Complex 41 at Cape Canaveral, Florida.

The 44-minute launch window stretches from 5:46 to 6:30 p.m. EST (2246-2330 GMT). Given the sunset time of 6:13 p.m., a liftoff anytime in the window could be spectacular as the 206-foot-tall rocket rises on a pillar or fire and smoke, weather permitting, of course.

With just 10 days left until flight, MUOS 1 took a middle-of-the-night road trip from the commercially-run Astrotech satellite processing campus in Titusville to the launch site aboard a trailer-like transporter.

The slow-moving drive crossed the river, went northward through Kennedy Space Center, passed by the Vehicle Assembly Building and the old space shuttle launch pad before cruising down along the beach to the Atlas rocket's Vertical Integration Facility.

MUOS 1 was delivered to the Cape on Dec. 15 from Lockheed Martin's factory in Sunnyvale, California, arriving inside an Air Force transport aircraft. The shipping crate was taken to Astrotech where the craft was unboxed for final testing, loaded with maneuvering propellants and encapsulated in the rocket's nose cone.

Check out this photo gallery of MUOS 1 being nestled into the Swiss-made launch shroud last week.

File image of payload being hoisted atop Atlas 5 rocket. Credit: NASA-KSC

After pulling up to the doorway of the Vertical Integration Facility this morning, technicians went to work attaching the heavy-duty lifting sling to hoist the spacecraft in the bullet-shaped fairing off the ground and atop the Centaur upper stage.

The United Launch Alliance-made rocket was assembled inside the VIF aboard a mobile launching platform over the past several weeks. It was wheeled out to the launch pad one-third-of-a-mile away last Monday for a countdown dress rehearsal and fueling exercise Tuesday before returning to the building on Wednesday to await the MUOS 1 installation.

Mating of the payload to the rocket was completed this afternoon, and then work began to affix the nose cone's ogive section to the lower base of the fairing.

Functional checks of the spacecraft and the combined systems test between MUOS and the Atlas vehicle will occur this week to verify the payload and rocket are talking to each other properly.

The fully stacked rocket, now standing 20 stories tall, features a main stage fed with refined kerosene and liquid oxygen, five strap-on solid propellant boosters, the liquid hydrogen-powered cryogenic Centaur upper stage and a composite payload shroud 16 feet in diameter.

Rollout to the pad for launch is slated for next Wednesday morning, leading to the 7-hour countdown sequence picking up Thursday at 10:46 a.m. Fueling operations begin shortly before 4 p.m. EST.

This is the largest, most energetic version of the Atlas 5 rocket currently available. The so-called 551 configuration has been used only twice in the previous 28 flights by the vehicle, launching NASA's New Horizons probe to Pluto in 2006 and the Jupiter-bound Juno orbiter last August.

File image of an Atlas 5-551 blasting off with Juno. Credit: Justin Ray/Spaceflight Now

Tipping the scales at nearly 15,000 pounds, the MUOS spacecraft needs that kind of power and three firings by the Centaur upper stage over the course of three hours to reach its targeted geosynchronous transfer orbit of 22,237 by 2,152 statute miles at 19 degrees inclination. A typical Atlas 5 ascent uses only two burns.

The craft's size also means the medium-length option in the range of Atlas nose cones was picked for this launch that features a 9-foot extension over the usual choice.

In its launch configuration with the two power-generating solar arrays stowed on the sides, MUOS is 22 feet tall, 12 feet wide and 6 feet deep.

A pair of gold mesh antenna reflectors, built by Harris Corp., at the heart of the satellite's communications payload will be unfurled like umbrellas on deployable boom assemblies once in space. Coverage to legacy users will transmit through a 17.7-foot-diameter reflector on the bottom of the craft and the advanced, multi-beam features of MUOS to significantly increase the transmission capacity over the Navy's previous satellites will use a large 46-foot reflector atop the satellite.

Lockheed Martin is producing five MUOS satellites -- four primes and one in-orbit spare -- to replace the Navy's current generation of Ultra High Frequency Follow-On spacecraft that were launched by Atlas rockets from 1993 through 2003. Eight of the 11 satellites remain in operation today.

The sophisticated MUOS system was designed around the commercial 3G cellular telephone architecture to substantially increase the number of users and amount of communications that can be routed to military forces.

"MUOS is designed to allow backward compatibility with legacy UHF terminals while providing a next generation waveform to support 'communications on the move' capabilities," said Mark Pasquale, Lockheed Martin vice president and MUOS program manager. "This ensures that legacy systems remain compatible with the MUOS architecture, while offering the technological advancements needed by its military users."

An artist's concept of MUOS. Credit: Lockheed Martin

MUOS will offer 10 times greater communications capacity to the mobile warfighter over the UHF F/O constellation to relay narrowband tactical information such as voice calls, data messaging, file transfers and email on rates of up to 384 Kilobits per second. It also enables users to communicate with smaller devices.

"Utilizing commercial 3G cell phone and satellite technology, MUOS will provide warfighters 'on the move' point-to-point and netted communications services at enhanced data rates and priority-based access to on-demand voice, video and data transfers," said Pasquale.

It will take about three months to maneuver the craft into the proper orbital position and conduct in-space testing before becoming operational.

"A single MUOS satellite provides more communication access than the current UHF constellation. This capability is critical to the U.S. military because they depend on reliable, targeted communication to complete missions and to protect service members worldwide," said Pasquale.

"MUOS is designed to support those requirements by providing users narrowband communications with greater mobility, higher data rates and improved operational availability."

MUOS 1 during encapsulation within Atlas nose cone. Credit: ULA

The Navy says approximately 67,000 UHF user terminals are deployed across the military branches serving around the world, many of them carried deep into theaters of operation.

The UHF communications provide command and control between combatant leaders and their warfighters, connectivity to tactical forces, communications for Special Operations and support to rapid deployments of land, air and naval forces worldwide.

Military officials have stressed the need for additional UHF channels to supply the diverse users of the system, something that MUOS is designed to give.

"The UHF spectrum is the military's communications workhorse because it is the only radio frequency that can penetrate jungle foliage, inclement weather and urban terrain," says the Navy.

The launch comes just a month after the Air Force deployed the latest in its growing fleet of Wideband Global SATCOM spacecraft offering X- and Ka-band frequencies to provide very high data rates up to 3.6 Gigabits per second for routing voluminous amounts of communications -- like large intelligence files and weather information -- to the battlefield and providing the links to and from the military's remotely-controlled aerial drones patrolling global hotspots.

MUOS, on the other hand, is geared toward to mobile receivers using lower-data-rate communications than WGS.

The military's other major communications satellite program, the Advanced Extremely High Frequency system to provide highly secure, jam resistant links between the president and military leaders will be launching its second satellite on the subsequent Atlas 5 rocket at the end of April.