Ariane 5 Rocket Launches Communications Satellite Pair
The W2M satellite is transported on a pallet that is easily controlled by a single launch team member during its movement through the S5 facility.
Credit: Arianespace.

One of the world's top commercial satellite operators used a heavy-lift Ariane 5 rocket to successfully get two of its new communications spacecraft into orbit Saturday evening.

It was a risky proposition for Eutelsat to entrust a pair of its satellites to just one rocket. Never before had the company put two pricey birds on a single launch. But when launch slots are increasingly difficult to secure, the Paris-based took the opportunity from launch provider Arianespace.

Blasting off from the Guiana Space Center on the northeastern coast of South America, the mammoth rocket carried out its crucial mission in only 32 minutes, as Eutelsat executives held their collective breaths.

The hydrogen-fueled Vulcain 2 main engine ignited as the countdown hit zero at 2235:07 GMT (5:35:07 p.m. EST), followed seven seconds later by lighting the twin solid rocket boosters to propel the Ariane 5 from the jungle launch base.

The launch occurred on the day's second try. An initial countdown was halted a scant 10 seconds before ignition because pressure in the liquid hydrogen system was out of spec. The launch team recycled the clocks and resolved the issue for liftoff 44 minutes into the hour-long window.

The solid motors provided nearly 90 percent of the power during the early climb into the night before burning out and separating. That left the main stage to continue pushing the vehicle out of the atmosphere.

About 9 minutes after liftoff, the cryogenic upper stage took control and performed a 16-minute burn that accelerated the payload into the targeted geosynchronous transfer orbit at 20,800 mph.

The two satellites, stacked atop each other, then began the choreographed deployment sequence that saw Hot Bird 9 released from the rocket 27 minutes into flight. The barrel-like structure that held the top satellite and enclosed the lower spacecraft was jettisoned a few minutes later, exposing W2M for its separation from the upper stage to complete the launch.

"I think you all admired this absolutely beautiful liftoff of Ariane," said Giuliano Berretta, Eutelsat's director general. "I would like to thank Arianespace for this beautiful performance."

The workhorse Ariane 5 now has accumulated 28 consecutive successes over the past five-and-a-half years.

Both satellites will use their onboard engines to ascend from the launch orbit to circular geostationary orbits 22,300 miles above the equator. Hot Bird 9 will be positioned at 13 degrees East longitude and W2M is headed for 16 degrees East.

Eutelsat operates a cluster of three satellites at its 13 degrees East orbital slot to beam nearly 1,100 television channels and 600 radio stations to 120 million homes across Europe, North Africa and the Middle East. Hot Bird 9 promises to increase the number of digital and high-definition TV offerings.

Built by EADS Astrium using the Eurostar E3000 platform, the craft is equipped with 64 Ku-band transponders for relaying transmissions directly to small dishes at users' homes.

A successful entry into service by Hot Bird 9 will allow the Hot Bird 7A spacecraft currently operating at that location to be moved into the 9-degree East position for replacement of the 12-year-old Eurobird 9 craft.

Users with dual-feed satellite dishes can receive programming from both the 9- and 13-degree orbital positions.

W2M was built under a collaborative effort between EADS Astrium and Antrix, the commercial arm of the Indian Space Research Organization. It has 32 Ku-band transponders for a wide range of telecommunications services, including television broadcasting, internet connectivity and business networking.

The craft will replace the W2 satellite launched 10 years ago and enhance Eutelsat's capacity to cover burgeoning markets in central and eastern Europe, the Mediterranean Basin, the Middle East and islands in the Indian Ocean region.

Eutelsat's two new satellites will be joined by three more next year and two in 2010 as part of the company's fleet expansion and renewal efforts.

"This successful dual launch of two Eutelsat satellites is a major step forward in our far-reaching in-orbit investment program for 2008-2011 and clears the way for Eutelsat to accomplish a raft of strategic objectives in terms of managing our in-orbit resources," Berretta said.

"These new resources underscore our ability to pursue sustainable growth in digital TV and broadband markets, which continue to confirm their dynamic potential."

Saturday marked the sixth and final launch of 2008 for the Ariane 5. The hoped-for record pace of seven missions this year fell short due to payload schedules.

Arianespace began the year with the launch of Europe's first Automated Transfer Vehicle, the robotic resupply ship that spent five months docked to the international space station. Five additional Ariane 5s flew during the year, each delivering pairs of communications satellites into orbit.

Next up will be Arianespace Flight 187, currently targeted for launch on February 12. It will carry Hot Bird 10 for Eutelsat and the delayed NSS 9 spacecraft for SES New Skies, the satellite originally slated for Saturday's mission but was replaced by W2M.

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