We need to test the HERON ground station by attempting to communicate with an existing satellite which uses the same frequency band as HERON. There are very few satellites which use the 70 cm band for both uplink and downlink. However, there is one particular satellite, known as “Greencube” which satisfies this requirement. Thus, communicating with Greencube should be a priority for the next ground station test. Greencube carries a biological experimental payload, and an amateur radio “digipeater” (digital repeater). This repeater can be used to send and receive packets using GMSK (the same modulation scheme as HERON), so communicating with Greencube is a good exercise in preparation for communicating with HERON. Lots of information is available online on how to communicate with Greencube; it is a popular target for satellite-oriented radio amateurs. Greencube was designed by the Sapienza University of Rome, in Rome, Italy. The satellite was launched by the European Space Agency.
Some websites to start learning about Greencube (NORAD 53106):