PONTE VEDRA, Fla. — Europe's Ariane 5 ECA rocket successfully launched Japanese and U.S. telecommunications satellites Aug. 14 in the fifth of a planned seven launches in 2008, and was the vehicle's 27th consecutive success.

The launch featured the first Japanese-built commercial satellite. Builder Mitsubishi Electric Corp. (Melco) said now it is ready to compete with the dominant U.S. and European manufacturers for commercial satellite contracts.

The Melco-built Superbird-7 satellite will be operated by Space Communications Corp. (SCC) of Tokyo at 144 degrees east longitude. SCC in March was purchased by SkyPerfect JSAT Corp. and as of October will be a division of that company.

Superbird-7, which will replace the Superbird-C satellite now at that orbital slot, is based on Melco's DS 2000 satellite frame. It weighed 4,820 kilograms at launch and is designed to deliver 8 kilowatts of power to the satellite's payload at the end of its 15-year operating life. The satellite carries 28 Ku-band transponders and will be used by SkyPerfect JSAT Corp. for television and telecommunications broadcasts, mainly in Japan.

SCC Chief Executive Yukata Nagai, referring to the fact that Superbird 7 is the first made-in-Japan commercial spacecraft ordered by a Japanese fleet operator, said after the launch: "I hope such satellites will be more widely accepted in the world satellite market based on this success."

Melco Senior Executive Officer Noboru Kurihara, who also attended the launch at Europe's Guiana Space Center in French Guiana, said: "Today's flight represents an event of historical significance for Mitsubishi Electric and, we hope, for the commercial satellite industry: the first Japan-made commercial telecommunications satellite. Now we have come up with our own standard satellite platform, the DS 2000. With the launch of Superbird-7, we will work to establish a firm position in the market as a competitive and reliable Japan-based commercial satellite manufacturer."

Riding alongside Superbird-7 was the AMC-21 satellite to be operated by SES Americom, the U.S. division of SES of Luxembourg, at 125 degrees west longitude. The first major customer for the satellite will be the U.S. Public Broadcasting Corp. AMC-21 was built by Thales Alenia Space of Cannes, France, which provided the electronics payload; and by Orbital Sciences Corp. of Dulles, Va., which built the satellite's Star-2 platform and also performed satellite integration and testing.

AMC-21 weighed 2,410 kilograms at launch and carries 24 Ku-band transponders. It is designed to operate for 15 years. SES Americom Chief Executive Rob Bednarek said AMC-21 also will be used to provide mobile broadband communications to the maritime industry. Bednarek said the Thales Alenia Space-Orbital Sciences team, along with the Arianespace launch consortium of Evry, France, delivered the satellite into orbit just 27 months after the construction contract was signed.

Arianespace Chief Executive Jean-Yves Le Gall said the next Ariane 5 launch is scheduled for October and will carry the Hot Bird 9 direct-broadcast television satellite for satellite-fleet operator Eutelsat of Paris, and the NSS-9 satellite for SES New Skies. Also on board will be the two small Spirale missile-warning demonstration satellites for the French arms procurement agency, DGA.?