Coverage for 4 Continents

The PAS-1R satellite, built for PanAmSat Corp. by Boeing Satellite Systems, Inc., brings satellite communications coverage to four continents from its slot at 45 degrees West longitude over the Atlantic Ocean. The satellite was successfully launched on Nov. 15, 2000 on an Ariane 5 rocket.

The satellite is a Boeing 702 model, carrying a payload of 72 active transponders. That is twice the capacity of PAS-1, the spacecraft PAS-1R replaced. The 702 is the largest and most powerful spacecraft in the Boeing line, using state-of-the-art technologies in propulsion, power generation and thermal control.

PAS-1R's footprint encompasses the Americas, the Caribbean, Europe and Africa. The 36-transponder C-band payload uses 34-watt and 55-watt power amplifiers for general telecommunications traffic such as voice, data and television relay. The 36 Ku-band transponders employ 125-watt and 140-watt amplifiers for direct-to-user services.

Boeing Satellite Systems introduced the 702 model in October 1995, as an evolution of its popular body-stabilized 601 line. The 702 can deliver payloads exceeding 90 active transponders, in any communications frequencies that customers request. Power levels start at 10 kilowatts and climb to 20 kilowatts in the 702+ configuration. The spacecraft is adaptable to medium and geostationary earth orbits.

Stowed (left); In Orbit (right)

Standard on the 702 is the advanced xenon ion propulsion system (XIPS) that Boeing Satellite Systems pioneered. XIPS is 10 times more efficient than conventional liquid bipropellant fuel systems. Four 25-cm thrusters provide economical attitude control, needing only 5 kg of fuel per year - a fraction of what bipropellant systems consume. PAS-1R employed XIPS for orbit-raising as well. The maneuvering takes about six weeks, compared to about a week with a bipropellant system; however, the savings in fuel weight is substantial.

As a new feature on the 702, angled reflector panels along both sides of the solar wings form a shallow trough and concentrate the sun's rays on the solar cells. These high-efficiency, dual-junction gallium arsenide cells supply twice the power of traditional silicon cells.

Separating the bus and payload thermal environments and substantially enlarging the heat radiators achieves a cooler, more stable thermal environment for both bus and payload. This increases unit reliability. The deployable radiators use flexible heat pipes, which increase the packageable radiator area.

PanAmSat, based in Wilton, Conn., is a leading provider of global video and data broadcasting services via satellite. The company builds, owns and operates networks that deliver entertainment and information to cable television systems, TV broadcast affiliates, direct-to-home TV operators, Internet service providers, telecommunications companies and corporations. PanAmSat has the world's largest commercial geostationary satellite network.

Boeing Satellite Systems is the world's leading manufacturer of commercial communications satellites, and a major provider of space systems, satellites and payloads for national defense, science and envrionmental applications.