Atlas rocket family extends launch success record
BY JUSTIN RAY
Posted: March 12, 2005
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.
"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."
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 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.
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.
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.
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