The DongFangHong 4 (DFH-4) is China’s third-generation large-capacity communications satellite. It is also China’s first indigenous direct broadcasting system (DBS), which can transmit data to users without the need for ground station rebroadcast. The primary contractor for the programme is China Aerospace Corporation (CASC), with the European company Alcatel Alenia providing some of its communications satellite technologies.
The DFH-4 weights 5,100kg and is three-axis stabilised. The satellite is equipped with 22 Ku-band transponders (four 54MHz and 18 36MHz), 3 receiver antennas, and 2 transmission antennas. With a designed operational life of 15 years, the DFH-4 can support the transmission of 150~200 TV programmes simultaneously to ground users using a 0.45m antenna device. The DFH-4 satellite also features strong capabilities against hostile disturbance and jamming. The satellite's power supply includes two 6m solar panels.
If being used for military purpose, the DBS satellite offers a capability for distributing information to the lowest echelon in a battlefield. Potentially the satellite can transmit data (maps, pictures, and enemy deployments) on demand to small units, each to receive orders and situational information using a manpack receiver.
Artist impression of the DFH-4 in the orbit (Source: Chinese Internet)
Development of the DFH-4 began in 2002. The first DFH-4 satellite, known as Sinosat 2 (or XinNuo-2 in its Chinese name), was intended to provide direct broadcast TV services for users in China mainland, Hong Kong, Macau, and Taiwan during the 2008 Beijing Olympic Game. The satellite was originally scheduled to be launched in 2005, but the launch was postponed due to technical reasons. On 28 October 2006, the Sinosat 2 was successfully launched by a CZ-3B space launch vehicle from Xichang Satellite Launch Centre (XSLC). However, the satellite’s solar panels and antenna failed to deploy, causing the RMB200 million (~US$25 million) satellite totally unusable. The satellite was last known to be stationed in GEO at 92.2 deg E.
A second DFH-4 satellite known as NIGCOMSAT 1 for Nigeria was successfully launched from Xichang on 14 May 2007. This was the first time that Chinese space contractors provided a packaged service including satellite design, manufacturing and launch for a foreign customer. As a part of the deal worth a total of US$311 million, the satellite will provide telecommunications, broadcasting, and broadband services for Nigeria.
A further three new satellites based on DFH-4 bus are currently being planned. The agreement between China Great Wall Industry Co. and Venezuela to launch the country's first communications satellite was signed in 2005. The satellite named VENESAT 1 is scheduled to be launched in April 2008. The Apstar 6B for the Hong Kong-based APT Group is to be launched in May 2008. The SinoSat 4 which was intended as a replacement for the failed SinoSat 2 will be launched in late 2008 or early 2009.
