Design of a Spacecraft Network System Based on Space-Ground Integrated Network

Since the rapid development of the internet technology, the space-ground integrated network is becoming an inevitable trend of development in communication between space and ground. At present, the internet technology to realize the integrated communication has been applied to ground stations. Similarly, the internet technology can be used in the communication system of spacecraft. But comparing to the network used on the ground, the space-link between the spacecraft and ground stations has different characteristics, such as the high propagation delay, the narrow bandwidth, the asymmetry transmission speed of the bidirectional space-link and the complicated Electromagnetic Compatibility (EMC) environment in the spacecraft. These can make the space-ground integrated network to be inefficient and unreliable. To resolve these problems, an efficient and reliable space network system for the spacecraft is designed based on the space Ethernet switch and the space-ground gateway. And the error-control mechanism of application layer, the IP package partition strategy of data link layer and the cable layout method of physical layer has been proposed to optimize the TCP/IP protocols used in the ground. The spacecraft network system can be used in the space-ground integrated network of GEO, MEO or LEO spacecraft and the deep space exploration.