MUMBAI: Broadband satellite Thaicom 4 (IpStar), the heaviest commercial satellite ever delivered to geosynchronous orbit, was lofted succesfully aboard an Ariane 5 launcher during an early-morning mission (5:20 am local time) yesterday, from the Kourou spaceport in French Guiana.

Built for Thailands' Shin Satellite by Space Systems/Loral at a cost of $400 million, the large telecom platform had a liftoff mass of 6,485 kg and will provide Internet access service to 14 countries across the Asia-Pacific region.

Once in operational service IPStar will generate 14 kW of electrical power during its planned 12-year mission life, providing Internet access and broadband services to businesses and consumers through 84 spot beams, three shaped beams and seven regional broadcast beams.

The launch was followed closely in Bangkok by more than 300 guests and 50 members of the media who attended a gathering organised by Shin Satellite. Guests watched Arianespace's video transmission of the mission, which provided a real-time monitoring of Ariane 5's final countdown. Shin Satellite executives are confident of signing contracts in China and India. Australia's Macquarie Telecom and New Zealand's BayCity are among the companies that have signed up.

The previous record for the heaviest satellite was Canadian telecommunications satellite Anik-F2, at 5.9 tons. That was launched by an Ariane-5 on 18 July, 2004.