CORAL Satellite

Exploring using a constellation of LEO satellites to offer IoT connectivity for TT&C purposes, as an alternative to ground stations.

Exploring the possibility of using a constellation of LEO satellites to offer IoT connectivity for TT&C purposes, as an alternative to traditional ground stations.

The mission indents to use ground IoT terminals on-board and use them to perform inter-satellite communication, transferring telecommands from the satellite currently visible from the current ground station to another satellite. This configuration would greatly extend the operability of a satellite by extending the period of time during which a satellite can be operated.

Part of the mission is testing the inter-satellite link with satellites which are already in orbit, like WildTrackCube-SIMBA, as well as testing the latency of the communication. The mission will simulate the entire TC&TM path from the main ground station to CORAL to the target satellite and finally to ground again.

scheduled to be launched from the ISS (International Space Station) in Q3 of 2024. The orbit is chosen as such to fall below the other communication satellites which typically employ SSO (Sun-Synchronous Orbit) above the ISS. The satellite is being developed by Sapienza University of Rome in collaboration with Thales Alenia Space Italia and Telespazio and with the support of ESA (European Space Agency).

The main payloads are three separate radios used for the inter-satellite link. The first radio is a copy of the one used on WildTrackCube-SIMBA and uses Chirp Spread Spectrum modulation. The radio will be used to communicate with WildTrackCube-SIMBA during conjunctions of the two satellites. The second radio uses Frequency Hopping Spread Spectrum or FHSS, which is a newer modulation used for IoT. In particular FHSS is used to avoid interference on a particular channel by changing both the transmitter and receiver frequency during communication. These tests will be performed in UHF and will take place with satellites already in orbit that serve ground IoT terminals.

The final payload radio is composed of a SDR (Software Defined Radio) which provides great flexibility for testing. The software of the SDR can be changed during flight to vary frequency, modulations and protocols. The SDR will be used for spectrum monitoring as well as tests of the NB-IoT protocol.

CORAL will be launched in Q2/Q3 2024 and will connect to different in-orbit terminals to verify the potential opportunities offered by IoT telemetry sharing systems within constellations or satellite clusters.