Europa Clipper Tones

The Europa Clipper mission will study Europa, Jupiter’s moon. Europa Clipper downlink communications will typically be X-band and Ka-band telemetry. However, there are a few key scenarios in the mission where telemetry will not close the link: Jupiter Orbit Insertion (JOI) and some safe modes. At these times, the spacecraft will utilize Multiple Frequency Shift Keying (MFSK) tones for downlink communications with Earth.The safe mode scenario is new for MFSK tones. During safe mode, tones will provide early visibility into the spacecraft’s health with a Deep Space Network (DSN) 34-m antenna before telemetry is available to a 70-m antenna. This early visibility will provide the spacecraft operations team with more information for spacecraft recovery. The Europa Clipper tones architecture is designed to support ground visibility into different types of spacecraft events and status in the two usage scenarios, JOI and safe mode.The tone design is flexible and tone selection criteria can be updated easily in flight. The safe mode scenario has low received signal power due to Europa Clipper’s distance from Earth. This is a challenging scenario and results in longer integration times being needed by the ground tones detection system. The design, testing, and planned operations of Europa Clipper tones are discussed and contrasted with past tones designs, including beacon tones and Mars EDL tones.