Riding the most powerful Atlas rocket in history, the world's heaviest commercial communications satellite is circling the Earth following Friday's fast and fiery blastoff from Cape Canaveral.

This stunning image of the Atlas 5 rocket launching Inmarsat 4-F1 was captured by a fisheye lens fitted on a sound-activated camera at Complex 41. Photo: Ben Cooper/Spaceflight Now

The Inmarsat 4-F1 spacecraft becomes the cornerstone in a sophisticated network providing mobile broadband communications services spanning the globe for users at sea, in the air and on land.

"Thanks to you all, the world just got a little smaller today," Inmarsat CEO Andrew Sukawaty told the Atlas launch team shortly after the successful liftoff.

"The satellite that just went up is the largest commercial satellite to be launched. There is a very important reason for that: we are looking to launch an exciting new service globally, and this was the first step in that.

"Putting almost half-megabit data speeds for people to access globally where terrestrial networks don't go, we see as a fundamental service. Some see it as a life-line service in some parts of the world, an essential service for media, for aid organizations, for maritime, which is a base of customers that has been with us for many, many years.

"It is an important service for the world and we just improved it in a major way, and you all made the world a little smaller."

The Lockheed Martin Atlas 5 rocket ascends from Complex 41. Photo: ILS

The $250 million launch was postponed a day, but the second attempt was uneventful as Lockheed Martin crews fueled up the 194-foot tall Atlas 5 vehicle at Complex 41 and aimed for liftoff at 4:42 p.m. EST (2142 GMT).

Blessed with Chamber of Commerce weather and a countdown free of any technical gremlins, the Russian-designed main engine thundered to full throttle in the last moments of the launch campaign that had taken years to reach culmination. Three 67-foot long solid-propellant booster rockets strapped to the first stage were then commanded to ignite, rapidly propelling the vehicle skyward on more thrust than any previous Atlas.

Within five seconds, the rocket has cleared the lightning protection towers around the launch pad. In contrast, earlier Atlas 5 rockets lacking any solid boosters for added liftoff kick took 13 seconds to ascend from the towers.

Following a 32-minute launch across the Atlantic Ocean, the Atlas 5 delivered Inmarsat 4-F1 into a super-synchronous transfer orbit, releasing the craft over Africa. The highly elliptical orbit featured a high point of 56,270 miles, a low point of 274 miles and inclination of 20.83 degrees.

The exceptionally high transfer orbit was targeted given the performance available from the launch vehicle and the fuel-saving efficiency it permits satellite controllers when conducting the orbital maneuvers to place the spacecraft into geostationary orbit.

The launch occurred in perfect weather conditions as seen from the Kennedy Space Center Press Site at Complex 39. Photo: Ben Cooper/Spaceflight Now

Over the next three weeks, the satellite's onboard propulsion system will circularize the orbit at 22,300 miles and reduce the inclination to approximately 0 degrees so that the craft can match the Earth's rotation and appeared parked over the equator.

The Lockheed Martin Atlas 5 rocket gave a tailored feel to its Inmarsat spacecraft payload, with three strap-on solid boosters and a stretched nose cone.

This particular configuration of the next-generation launcher -- called the Atlas 5-431 model with a four-meter fairing, three solids and single-engine Centaur upper stage -- had never flown. But its debut appeared flawless, and extended the string of consecutive successful missions by the Atlas family to 76 since 1993, including all five Atlas 5 flights. The joint U.S.-Russian firm International Launch Services, which markets the Atlas and Proton rocket fleets, managed the mission.

"Years of effort, 7 years from the inception of this project, went into this," Sukawaty said. "Teams of people have been dedicated to this for a healthy part of their careers. You at ILS certainly have a reputation that can't be matched in terms of reliability, and I saw it in action today. It was impressive. Thank you all very much."

The Inmarsat 4-F1 satellite weighed 13,138 pounds at launch. By far the heftiest commercial communications spacecraft launched from Cape Canaveral, its official liftoff mass was a bit heavier than earlier predictions. As a result, it eclipsed by a tiny margin the previous record-holder's weight to become the heaviest satellite of its kind deployed into orbit.

As seen from Port Canaveral, the Atlas 5 rocket launched into crystal clear skies. Photo: Steve Harrison

"This is a milestone launch for us...in terms of the size of the payload," ILS President Mark Albrecht said. "Inmarsat 4-F1 is one of largest commercial communications satellites in the world, as well as the most massive satellite launched by Atlas. Yet it falls into the middle of the Atlas 5 capability range, demonstrating the flexibility of our design."

Lockheed Martin designed the Atlas 5 family to incorporate various configurations, allowing each rocket and its specific payload to be paired together with just the right amount of power. The rocket can be fitted with as many as five strap-on solid boosters to loft over 19,000 pounds into geosynchronous transfer orbit. Before Friday's flight, the most solids used on a single Atlas 5 launch was two.

The Inmarsat 4-F1 craft is the first of Inmarsat's newest generation of satellites that come with the tag line "broadband for a mobile planet." Built in Europe by EADS Astrium, the Inmarsat 4-series spacecraft will provide office-like broadband services such as Internet, email, voice and data-relay using laptop and palm-sized terminals on land, at sea or in the air.

"It's really about taking the office with you where terrestrial networks don't go economically," Sukawaty said.

What's more, the Inmarsat 4-series of satellite will continue the existing lower-data-rate capacity currently offered by the London-headquartered company for maritime, air and emergency services, and enhance navigation signals for air traffic uses.

"Basically, it is going to expand our services and extend the life of our service to the end of the next decade," Sukawaty said.

An artist's concept shows the Inmarsat 4-series satellite in orbit. Credit: EADS Astrium

The sophisticated satellites transmit over 200 spot beams to deliver strong signals to the small receivers. Each craft has a giant unfurlable antenna reflector stretching 30 by 39 feet.

The new craft are 60 times more powerful and have 20 times more capacity than their predecessors, the Inmarsat 3-series of satellites. Inmarsat has 9 older satellites in orbit.

Inmarsat 4-F1 will be operated at 64 degrees over the Indian Ocean to cover Europe, Africa, the Middle East and Asia. A sister satellite -- Inmarsat 4-F2 -- is scheduled to fly later this year atop a Sea Launch rocket to serve South America, most of North America, the Atlantic Ocean and part of the Pacific Ocean.

"The first two I-4 satellites will bring broadband communications to 86 percent of the world," Sukawaty said.

A third craft is under construction for back up to the first two. If not needed as a replacement, the F3 craft could be deployed over the Pacific.

Video coverage for subscribers only:
VIDEO: ATLAS 5 ROCKET BLASTS OFF WITH INMARSAT 4-F1 QT
VIDEO: WATCH EXTENDED LENGTH LAUNCH MOVIE QT
VIDEO: ONBOARD VIEW OF SOLID ROCKET BOOSTER SEPARATION QT
VIDEO: LAUNCH AS SEEN FROM THE PRESS SITE QT

VIDEO: NARRATED ANIMATION PREVIEW OF THIS LAUNCH QT
VIDEO: OVERVIEW OF INMARSAT AND ITS NEWEST SATELLITE QT
VIDEO: TECHNICAL BRIEFING ON THE INMARSAT 4-F1 SPACECRAFT QT
SUBSCRIBE NOW