The Ariane 4 rocket blasts off with JCSAT-8 and Astra 3A from the ELA-2 launch pad. Photos: Arianespace

A pair of Japanese and European satellites, both built in the U.S. by Boeing, shared a ride into space Thursday night atop an Arianespace Ariane 4 rocket.

Liftoff occurred right on schedule at 8:29 p.m. EST (0129 GMT Friday) from the Guiana Space Center in French Guiana on South America's northeast coastline.

The venerable launcher flew in its most powerful configuration -- the 44L version with four liquid-propellant strap-on boosters.

About 19 minutes into flight, the targeted geosynchronous transfer orbit was achieved, with a high point of 35,995 km, low point of 249.8 km and inclination of 4.0 degrees to the equator.

The JCSAT-8 spacecraft, built by Boeing Satellite Systems for JSAT Corp. of Tokyo, was released into space from the Ariane's upper stage 21 1/2 minutes after launch.

The satellite is also known as JCSAT-2A. It will become the successor to the aging JCSAT-2 spacecraft launched on December 31, 1989 aboard a commercial Titan 3 rocket from Cape Canaveral.

Over the coming weeks, controllers will maneuver JCSAT-8 into a circular geostationary orbit 36,000 km above the equator where it will be parked at 154 degrees East longitude.

At that vantage point, JSAT will use the satellite to provide television and other telecommunications services across the Asia-Pacific region.

An artist's concept of the JCSAT-8 satellite in space. Photo: Boeing

JSAT is the leading satellite operator in Asia and has a fleet of orbiting craft that serve a wide span of the globe from Pakistan to Hawaii.

With JCSAT-8 deployed, the Ariane rocket ejected the dual payload adapter called Spelda. The structure enables two satellites to be stacked atop each other for launch aboard a single rocket.

Once the Spelda was released, the Astra 3A satellite was exposed and ready to separate from the launcher. Deployment occurred just over 27 minutes into the flight, concluding the 68th consecutive successful launch of the Ariane 4 dating back to 1995.

Astra 3A will also ascend into geostationary orbit, ultimately reaching a spot at 23.5 degrees East longitude.

Built by Boeing for Luxembourg-based SES Astra, the barrel-shaped satellite will be used to provide direct-to-home TV programming to subscribers of the Astra system.

The craft is destined to serve Germany, Austria and Switzerland, transmitting cable TV feeds and supporting broadband and Internet services. It will also provide follow-on capacity for Deutsche Telekom's Kopernikus satellite at the same orbital location.

An artist's concept of the Astra 3A satellite in space. Photo: Boeing

At the end of 2001, 91.3 million European homes received Astra. Astra is owned and operated by SES Astra, a wholly owned subsidiary of SES GLOBAL, the world's premier satellite operator.

Arianespace said this was the 60th dual satellite launch it has performed in 149 flights. It was the first time in about six years that Boeing Satellite Systems, formerly Hughes Space and Communications, has flown two satellites together in this fashion.

"Our last dual launch was in early 1996," said Randy Brinkley, president of Boeing Satellite Systems. "Getting two different customers' satellites ready for the same launch can only happen as a result of a tremendous and highly coordinated effort by our factory, our customers and the launch provider."

Thursday's launch was Arianespace's fourth of 2002. Next up is the planned April 16 launch of an Ariane 4 carrying the Lockheed Martin-built NSS-7 telecommunications spacecraft for New Skies Satellites.

There are just six Ariane 4 rockets left to fly before the vehicle is retired in favor of the next-generation Ariane 5, which successfully returned to flight a month ago after suffering an upper stage failure last summer.

"After a very in-depth analysis of Ariane 5, this analysis has shown our Ariane 5 worked perfectly and we are definitely back in business with this launch vehicle," Jean-Yves Le Gall, Arianespace's chief operating officer, said Thursday night.

The next Ariane 5 launch is expected in a couple of months.