Space internetworking with CCSDS Space Packets

Some space agencies are planning to launch constellations of space elements for space exploration or space science programs. In these constellations, some spacecraft are sometimes required to relay data to and from other spacecraft. In constellations having such relay spacecraft, the capability of space internetworking is required because the onboard networks of the participating spacecraft must be interconnected. Most current space projects use CCSDS Space Packets for data transfer, but CCSDS Space Packets do not have a capability for performing space internetworking. This paper proposes a method for realizing space internetworking using CCSDS Space Packets with only a minor modification. The method proposed in this paper uses the technique of encapsulating Space Packets into other Space Packets. This method has several advantages over using special protocols for realizing space internetworking: (1) this method enables development of space internetworking with a very small cost; (2) this method is scalable; and (3) this method facilitates interoperability among different space agencies.