The Ariane 5 rocket launched on another flawless mission Wednesday evening with a British space-based military communications relay station and a multi-purpose communications satellite for Brazil.

The workhorse rocket leapt away from its launch pad in Kourou, French Guiana, at 2206 GMT (5:06 p.m. EST). The Ariane 5, making its fifth flight of the year, set off on an easterly course from the launch site moments after liftoff.

The rocket's twin solid rocket boosters, first stage and cryogenic upper stage all performed well during the launch. The second stage released the two satellite payloads about a half-hour into the flight.

The Ariane 5 hit its marks during the voyage to space, arriving in an elliptical geostationary transfer orbit with a low point of 155 miles, a high point of 22,340 miles, and an inclination of six degrees. All of the orbital parameters were within pre-flight targets.

The British military's Skynet 5B communications satellite was deployed first, followed about six minutes later by the separation of Star One C1, a Brazilian broadcasting spacecraft.

Arianespace hailed the launch as a complete success, marking the Ariane 5 rocket's 21st consecutive successful flight dating back to 2002.

The mission set a new lift record to geostationary transfer orbit with a total mass of more than 21,000 pounds, including both paying passengers and a dual-payload adapter. The number surpassed a mark set by another Ariane 5 launch in May.

"Since the beginning of 2007, 12 large commercial communications have been launched [worldwide], and we launched 10 of them - 83 percent of the total, which is also a record," said Jean-Yves Le Gall, chairman and CEO of Arianespace.

Skynet 5B joins a fleet of spacecraft that relay communications between commanders and troops for Britain's Ministry of Defense.

The 10,218-pound satellite will circularize its orbit at an altitude of 22,300 miles during the next few weeks. Skynet 5B's permanent home in geostationary orbit will be along the Equator above the northern Indian Ocean.

After a testing campaign, control of the satellite will be handed over to Paradigm Secure Communications, the operator of the Skynet 5 system for the United Kingdom.

Paradigm is wholly owned by EADS Astrium, which is the prime contractor for the construction of both the Skynet 5 satellites and the Ariane 5 rocket.

"It's yet another significant success for Astrium," said Patrick Wood, Skynet program director at EADS Astrium. "In fact, you could say another triple success for Astrium."

The satellite's X-band payload will be able to reach users across Europe, Africa, the Middle East, and much of Asia. The craft is equipped with super-high-frequency and ultra-high-frequency antennas to provide secure voice, video and digital communications between military commanders and troops stationed around the world.

The antennas are hardened against nuclear attacks and feature anti-jamming capabilities, according to Paradigm.

"Skynet 5 breaks the mold," said Malcolm Peto, Paradigm's managing director. "It's the one-stop shop for the U.K. military for all their satellite beyond line-of-sight needs."

Skynet 5B is expected to remain in service for up to 15 years. The craft joins another satellite launched earlier this year, and a third Skynet 5 satellite is scheduled for launch on another Ariane 5 mission in mid-2008.

The Skynet system is part of a European satellite communications coalition formed by the United Kingdom, France and Italy. The countries won a contract in 2004 to deliver secure communications services from their satellite fleets to NATO member nations.

Paradigm has other agreements with the governments of the Netherlands, Canada, Portugal, Australia, and Belgium.

The Ariane 5 booster also hoisted the Brazilian Star One C1 communications satellite during Wednesday's launch.

With a liftoff weight of 9,039 pounds, the spacecraft will deliver telecommunications and broadband Internet services across Latin America and the southern United States. Star One C1 will be stationed in geostationary orbit at 65 degrees West longitude.

The satellite is beginning a 15-year mission for Star One, a subsidiary of Brazilian operator Embratel. Star One is also partly owned by General Electric International.

Star One C1 is the first member of the company's third generation of satellites.

"With this new satellite, Star One will be able to confirm its leadership as the largest regional satellite operator in Latin America," said Lincoln Oliveira, Star One's chief technical officer.

Television signals from Embratel satellites reach about 16 million homes throughout Brazil, according to the company.

Star One C1 will replace Brasilsat B2, an aging 12-year-old satellite near the end of its operational life span. The replacement satellite is twice as powerful as its older counterpart, according to Embratel.

"The new generation of satellites has more power, more coverage, and will enable the expansion of services to other companies and to the people as well," said Gustavo Silbert, president of Star One.

Built by Thales Alenia Space, Star One C1 carries 28 C-band and 16 Ku-band transponders for voice, data and direct-to-home broadcasting services. A lone X-band transponder on the satellite will be restricted to military use.

The launch of another Star One satellite is slated for February to further augment the company's fleet, according to Embratel.

Two more missions are on the books for Arianespace to round out the year. A Soyuz rocket launched from Kazakhstan will carry Canada's Radarsat 2 spacecraft into orbit on Dec. 14, followed a few days later by another Ariane 5 mission with the Rascom 1 and Horizons 2 satellites.

Copyright 2007, all rights reserved.