HG3PQSAT Spacecraft

Demonstrating ADCS technologies, imaging, deployable solar panels, and multiple amateur-radio telemetry and repeater modes.

HG3PQSAT is going to be the 7th of ham and equcational satellites in Hungary, made by university students, integrated into the higher education (Masat-1 was 1U cubesat, as the first; 2. SMOG-P 1-PQ; 3. ATL-1 2-PQ; 4. SMOG-1 1-PQ; 5. MRC-100 3-PQ, NMHH-1 3-PQ). Everyone of the development team is radioamateur (student and/or lecturer).

The main payloads of the 3-PocketQube 5x5x15cm HG3PQSAT satellite are:

• Attitude Determination and Control System (ADCS) with 4-axis electromagnets is 3-PocketQube – based on MRC-100 (the previous 3-PQ satellite)
• ADCS with 4 axis switched reluctance motors (SRM) as flying wheels
• Color imaging camera
• HAM GMSK digital telemetry beacon
• Half-duplex FSK HAM repeater
• AM LoRa (linear-FM-chirp) digital telemetry beacon
• Half-duplex LoRa HAM repeater
• Cross band digital repeater 437MHz up, 2400MHz down
• Deployable solar panels to maximize the incoming DC power to supply mainly the beacons and repeaters.

Half-duplex FSK HAM repeater: in time, after the digital telemetry data, the on-board communicational system receives digital 2-FSK signal from any radioamateur from the Earth, after some seconds, the satellite re-transmit it back to the Earth on the same frequency (similar to the old packet-radio) – only hand-held FM transceiver with e.g. 6-element Yagi antenna + laptop with sound card are necessary for this transmission using our public modulator and demodulator software.

Half-duplex LoRa HAM repeater: similar to the FSK one, but the used linear-FM-chirp based modulation scheme allows HAMs to use minimal configuration ground station only with omnidirectional monopole or dipole antenna, no azimuth and elevation tracking, no Doppler correction, with max. 100mW ERP (20-30dB below the noise power level). The FSK and/or LoRa based digital half duplex system can be used as “satellite on-board repeater” to make HAM QSOs with each other, when the satellite is line-of-sight. The repeater trasmissions will be recorded on-board non-volatile memory. It can be downlinked as telemetry data with timestamp over Hungary after telecommand.