Crews have fitted the Ariane 5 heavy-lift launch vehicle with an increased-performance ESC-A upper stage, Arianespace said Tuesday. The work is part of preparations for the rocket's scheduled mid-May launch from Europe's spaceport carrying the Satmex 6 and THAICOM 5 communications satellites.
Ariane 5's new upper stage will be powered by the same 6.5 metric on HM-7B engine as used in Ariane 4's third stage. Designed for a single ignition during flight, the HM-7B operates on liquid oxygen and liquid hydrogen. The upper stage will carry 15.4 tons (14 metric tons) of the cryogenic propellants.
The ESC-A will enable Ariane 5 to place 10,000 kilograms into the required geostationary transfer orbits on the dual-payload mission, using the Sylda multiple-satellite deployment system, and 10,500 kilograms into GTO carrying a single large payload.
Satmex 6 is capable of generating 14.1 kilowatts to power its 60 transponders, which include 36 C-Band transponders covering North, Central and South America; 24 Ku-Band transponders serving the United States, Mexico and elsewhere in North America, and a hot spot serving major cities in South America.
Thaicom-5 will replace Thaicom 1 and 2, due to be retired in 2008 and 2009, respectively. It will allow its operator, Shin Satellite Public Company Ltd., to expand its Ku-Band channels over Thailand and neighboring countries. It will provide high quality broadcasting, telecommunications and broadband services. Its 5 kilowatts will power 24 C-band and 14 Ku-Band transponders.
