On November 15, 2004, China Great Wall Industry Corp. (CGWIC) and Hong Kong-based APT Satellite Co., Ltd. (APT) signed a contract in Beijing for the in-orbit delivery of the APSTAR-6B satellite. According to the contract, satellite in-orbit delivery service provider CGWIC will launch the DFH-4 platform-based APSTAR-6B satellite into a pre-determined orbit. APT is the operator of the APSTAR-6B communications satellite.
The DFH-4 satellite platform developed and manufactured by the China Academy of Space Technology (CAST) is a new-generation satellite platform designed to meet the needs of the international communications satellite market. DFH-4 platform-based satellites are characterised by their high capacity and extended in-orbit life span.