Software for Spacecraft/Ground Communication via the Internet

The Space Communications Protocol Standards (SCPS) specify a developmental system of international protocols for data communications between spacecraft and points on Earth. SCPS protocols are intended to make a spacecraft appear, to a terrestrial computer user, as just another node on the Internet. The protocols are implemented to be as interoperable as possible to other systems. The SCPS file protocols are based partly on the Internet File Transfer Protocol (FTP), but include additional features necessary for smooth communication over channels that include interruptible Earth/spacecraft links; unlike the Internet FTP, the SCPS protocols provide for restart of interrupted file transfers and provide record read/update services. The SCPS protocols include (1) a file-handling protocol based on the Internet FTP, with modifications to optimize performance for typical spacecraft data streams; (2) an underlying retransmission protocol based on the Internet Transmission Control Protocol (TCP), with modifications to ensure reliability in the face of interruptions; (3) a data-protection protocol derived from a number of security protocols; and (4) a scalable networking protocol for routing of messages, based on the Internet Protocol (IP), with modifications to support space routing and increase communication efficiency.