1 An Interface Specification for Requesting Space Link Extension Services from NASA TT&C Networks

The Consultative Committee for Space Data Systems (CCSDS) has produced Recommendations (specifications) for several Space Link Extension (SLE) transfer services for the standardized, interoperable exchange of spacecraft telemetry and command data between a spaceflight mission’s ground facilities and the tracking, telemetry, and command (TT&C) networks that are used to communicate with the mission’s spacecraft. The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL) Deep Space Network (DSN) have implemented these SLE transfer services. Other space agencies are prototyping SLE services, several spaceflight missions have already adopted SLE, and JPL has adopted SLE as the standard interface between mission facilities and the DSN for the foreseeable future. NASA’s Space Network (SN) and Ground Network (GN), as well as other national space agencies, are evaluating the adoption of SLE services as their standard for future mission support. The type, number, and operational characteristics of the SLE services can vary from mission to mission, resulting in the need for management interaction between the mission and the supporting TT&C network. This management interaction nominally includes:- Pre-flight agreement(s) between the mission and the TT&C network that specify the limits o