Spacecraft-To-Earth Communications For Juno And Mars Science Laboratory Critical Events

This paper describes the Entry, Descent, and Landing (EDL) Data Analysis system (EDA). The EDA software supports the real-time interpretation of Multiple Frequency-Shift Keying (MFSK) tones provided by the spacecraft. The objective of this software is to provide communication of status between the spacecraft and the mission personnel on Earth during critical events when low rate telemetry is not possible due to high dynamics and low signal-to-noise ratio (SNR). Although these communications cannot be used to affect the landing due to the length of time required at these distances, this information is important in the case of a mission failure. Mars Science Laboratory will utilize the EDA software during EDL. Juno usage will include Jupiter orbital insertion (JOI), with predicted SNR of 12-15 dB-Hz. Results are presented from the Juno tones test. Simulated signals were also generated for Juno at JOI and Mars Science Laboratory (MSL) EDL and these results are analyzed.