Proton rocket lifts off from pad 23 at Baikonur's Complex 81. Photos: Spaceflight Now/ILS TV

A telecommunications spacecraft that will orbit above the Indian Ocean to serve an area where 80 percent of the planet's population resides and replace an ailing sister-satellite was successfully delivered into space today by a Russian Proton rocket.

The marathon six-and-a-half hour mission of the powerful Proton began 0111:30 GMT (9:11:30 p.m. EDT Monday) from the Baikonur Cosmodrome in Kazakhstan. The rocket's six first stage engines roared to life right on schedule and carried the 1.5-million pound vehicle into the skies of Central Asia just after daybreak there, creating a colorful spectacle during ascent.

The Proton's first three stages fired as planned and hurled the Block DM upper stage and attached PAS-10 satellite into a temporary parking orbit around Earth within 10 minutes of liftoff. From there, the upper stage cruised for nearly an hour before firing to begin the journey to geostationary orbit for its precious cargo.

The Block DM's first burn raised one side of the orbit to about 35,000 km. Then the wait began as the vehicle coasted along its stretched orbit before a second firing occurred to raise the low end above 7,000 km and reduce inclination to the equator.

PAS-10 was released into its egg-shaped geosynchronous transfer orbit at approximately 0744 GMT (3:44 a.m. EDT) to complete the launch, which marked the 286th for a Proton rocket dating back to 1965 and the second of 2001. The orbit achieved was near-perfect with a high point of 35,994.9 km, low point of 7,141.4 km and inclination of 17.01 degrees.

Controllers quickly established contact with the satellite via the Hartebeesthoek ground station in South Africa, confirming that onboard systems were functioning normally following the ride to space.

Later this month PAS-10 satellite will fire its onboard kick engine to achieve a circular orbit 36,000 km over the equator, a perch that will match the Earth's rotation allowing the craft to appear fixed above a particular spot of the globe.

That final parking slot will be over 68.5 degrees East longitude where it will replace PanAmSat's PAS-4 spacecraft as the Greenwich, Connecticut-based company's Indian Ocean Region satellite, reaching about 60 percent of the planet's land mass that is home to more than 80 percent of the world's population.

An artist's concept of PAS-10. Photo: Boeing Satellite Systems

Built by Boeing Satellite Systems, PAS-10 is a 601HP model satellite carrying 24 C-band and 24 Ku-band transponders to relay television and high-speed data transmissions and provide Internet services across parts of Europe, the Middle East, Africa, Asia and the Indian subcontinent.

PAS-10's C-band payload will be used by some of the leading international broadcasters and programmers, including the BBC, CNN, CCTV, Discovery, Doordarshan, ESPN, MTV, NHK, Nickelodeon, Sony and TNT.

The Ku-band payload, which offer 60 percent more transmission power than PAS-4, contains multiple high-powered beams focused on specific parts of the satellite's coverage zone for the delivery of data and IP-based services.

"PAS-10's successful launch will ensure that emerging markets in the Indian Ocean Region, including the Indian subcontinent and Central and Western Asia, have access to the latest services delivered over the most dependable technology," said R. Douglas Kahn, PanAmSat's president and chief executive officer.

The PAS-10 satellite is destined to take over the job of PAS-4, which was launched in August 1995 and suffers from a design flaw that has stricken several Boeing-built spacecraft of the same make. The Boeing 601 model satellites flown before August 1997 have tin-plated relay switches that can experience electrical shorts, causing the onboard Spacecraft Control Processor (SCP) to fail.

Mission poster for the launch of PAS-10. Photo: ILS

PAS-4's primary SCP failed in November 1998 and the craft is currently running on its backup computer brain. Should that last remaining SCP malfunction, the satellite would be a total loss -- a fate that has already ravaged a couple of Boeing 601s.

"PanAmSat decided to replace (PAS-4) to address the concerns of our customers. This represents a quarter-billion dollar investment, which is a very significant investment for any company," said Kahn.

PAS-10 marks PanAmSat's sixth new satellite in less than 18 months. The company began a comprehensive plan in late 1998 to expand its satellite fleet and replace suspect spacecraft that had experienced or could suffer the SCP design flaw. Another craft -- Galaxy 3C -- is set to go up in July aboard a Sea Launch Zenit rocket to replace the Galaxy 3R satellite that has lost its primary SCP.

Today's flight marked the 20th Proton rocket mission managed under the auspices of International Launch Services. ILS was formed in 1995 as a joint venture of American Lockheed Martin Corp. and Russian Khrunichev State Research and Production Space Center and RSC Energia, and globally markets the Atlas and Proton rocket fleets.

The next ILS Proton is scheduled for mid-June with the European Astra 2C direct-to-home TV satellite. The other firm ILS launch booked on Proton this year is slated for December carrying another Astra spacecraft.