For radio amateurs


On March 22, our spacecraft is launched into orbit by launching a Soyuz-2.1a rocket with a Fregat upper stage from the Baikonur cosmodrome. 

We invite all radio amateurs to take part in receiving signals. We have prepared a software package that will allow you to decode almost all types of data that will be transmitted from satellites, primarily beacons, as well as connect to a centralized telemetry database and transmit received packets to us and all radio amateurs (this option can be prohibited).

Information about frequencies and call sign:

437,850 MHz и 437,950 MHz – GMSK 9600, USP (see below);
10465 MHz – DVB-S2

The transmitter at 437,850 is the main one. It uses dipole antenna that deploys simultaneously with solar panels. The transimitter at  437,950 MHz is a backup one. It uses patch antenna. The last one is quite directional, so significant amount of rotational fading should be expected.

The USP protocol is designed by our company. It uses FEC (convolutional coding + RS coding) to improve a link budget. Its detailed description and GNURadio flowgraph are attached. To decode packet fields and for data presentation SPUTNIX Telemetry Viewer  can be used.

SPUTNIX Telemetry Viewer uses AGWPE/KISSTCP interfaces to connect GNURadio flowgraph or (if you are going to receive UniCAN over AX.25) can be used along with typical SDR software like Orbitron/SDRSharp and UZ7HO's SoundModem/direwolf through AGWPE/KISSTCP interfaces. Configuration file path is "resources/config.xml". Please, set your call sign (or substitute it with unic 6-characters name) and localtion in that file. By default, received data will be transferred by SiDS protocol (it’s used by SatNOGS network), but you can disable it in the same configuration file.

USP detailed protocol description

Preliminary orbital data

GnuRadio flowgraph

Download SPUTNIX Telemetry Viewer (Win RU) — stay tuned for update!

Download SPUTNIX Telemetry Viewer (Win ENG) — stay tuned for update!

Download SPUTNIX Telemetry Viewer (Linux RU) — stay tuned for update!

Download SPUTNIX Telemetry Viewer (Linux ENG) — stay tuned for update!

The configuration file — stay tuned for update!

Download Test I/Q Signal (SDR Sharp) 

Download Test I/Q Signal (GNU Radio) 

(sample rate is 480 kHz)


P.S. There are few more satellites on the same launch, which are going to use the same or similar protocols. They are: CubeSX-HSE, CubeSX-Sirius-HSE, KSU-CubeSat.

CubeSX-HSE  call sign RS13S
435,650 MHz – GMSK 9600, USP
10455 MHz – DVB-S2 protocol

CubeSX-Sirius-HSE call sign RS14S
435,050 MHz – GMSK 9600, USP
10465 MHz – DVB-S2 protocol

KSU CubeSat call sign KSU1C
437,130 MHz – GMSK 4800, AX.25

We should note, that RS13S and RS14S call signs were used on SiriusSat-1,2 satellites, but they were reused by local regulator by unknown reason.