Soyuz-2.1a / Fregat Baikonur launch 2021-03-22T06:07 UTC

Okay, we’re back! Some satellites in the amateur band that we know about:

  1. CubeSX-HSE 3U 435.650 MHz GMSK 9600. Call sign RS13S. USP FEC protocol, see the link below.
    Separation time: 10:25:32 UTC
    Beaconing time: 10:30:32 UTC
    Preliminary TLE:
    1 90000U 21320A 21079.43439815 .00001366 00000-0 57340-4 0 0016
    2 90000 97.5800 343.0700 0017260 161.7000 128.0646 15.08643269000010

  2. CubeSX-Sirius-HSE 3U 437.050 MHz GMSK 9600. Call sign RS14S. USP FEC protocol, see the link below.
    Separation time: 10:25:42 UTC
    Beaconing time: 10:30:42 UTC
    Preliminary TLE:
    1 90001U 21320B 21079.43451389 .00001366 00000-0 57340-4 0 0017
    2 90001 97.5800 343.0700 0017320 162.6600 127.7234 15.08616927000014

  3. ORBICRAFT-ZORKIY 6U 437.850 MHz GMSK 9600, 2nd transceiver 437.950 MHz GMSK 9600. Call sign RS15S. USP FEC protocol, see the link below.
    Separation time: 10:30:32 UTC
    Beaconing time: 10:35:32 UTC
    Preliminary TLE:
    1 90004U 21320E 21079.43787037 .00001422 00000-0 59507-4 0 0012
    2 90004 97.5700 343.5500 0017660 189.5900 118.9532 15.07090652000010

  4. KSU-cubesat 1U 437.130 MHz GMSK 4800. Call sign KSU1C. AX.25 protocol.
    Separation time: 10:27:12 UTC
    Beaconing time: 10:32:12 UTC
    Preliminary TLE:
    1 90003U 21320D 21079.43555556 .00001702 00000-0 84401-4 0 0012
    2 90003 97.5700 343.0800 0017380 173.0300 122.9933 15.08037631000017

Link about USP FEC protocol with some description and example GNU Radio flowgraph:

We’ll release more info next few days, piece by piece :). Questions are welcome.

CubeSX-HSE.txt (150 Bytes) CubeSX-Sirius-HSE.txt (157 Bytes) KSU-cubesat.txt (151 Bytes) ORBICRAFT-ZORKIY.txt (156 Bytes)


Thanks for the info @sputnix !

@surligas can you have a look and let us know about the compatibility with our exisitng demodulators? Obviously the decoding will happen on a kaitai-struct. @sputnix are you up for creating those with us and make the dashboards?


About demod and FEC decode:
Historically we use gr-satellites a lot. We’ve updated stuff as much as possible, but sticking with GNU Radio 3.8 still. We are also still doing our flowgraphs with as little OOT as possible, mostly gr-satellites and doppler stuff. This way has some advantages. Some of the blocks and techniques we use in the example USP flowgraph attached are dated and probably not optimal, but tested a lot since 2018. We are looking forward to learning about the current state of gr-satellites, gr-satnogs, their compatibility, and what we can do better. Last time we checked(like half-year ago) we’ve found that:

  1. In order to be compatible with SatNOGS our flowgraphs most probably should change gr-satellites blocks to gr-satnogs ones.
  2. It was not clear how to include GRC-block(like hier, not .py/.cpp) in gr-satnogs pipeline.
    We’ll start research these topics again tomorrow.

About TM descriptions:
We are up to do it. IIRC last time it looked like this: SPUTNIX XMLs => conversion to JSON => kaitai. XMLs from prev launch(SiriusSat-1 and 2) are pretty compatible, but some things added, updated, documented. We’ll release some updated XMLs soon.

Anyway, we’re ready to do some coding :).


Wauw, thanks for all the information shared.

Good luck with the missions

1 Like

A question about the USP/FEC solution.

Is this also part of the main/master gr_satellites repository?
This would make it easy to create, maintain the yaml files within one repository.

1 Like

Hey @sputnix, thanks for the info. gr-satnogs follows a different approach for adding a new satellite decoder. The demod part should be exactly the same for the rest of the FSK/MSK satellites, so only the framing structure and its coding varies. Adding a new framing scheme is quite easy in terms of modifications and it is described at

I will start a new branch and post here the progress. Of course, you can contribute also if you like. Meanwhile if you have any IQ capture that you can share, it will be great!


Not yet in gr_satellites. We are ready to participate, especially if the launch is ok :).

1 Like - we’ve uploaded IQs, 480 kHz sample rate. You can also see a translated version of a more elaborated USP protocol description, in more detail than on GitHub. We’ll try to follow the guide, thank you! All updates will be here, GitHub/etc, and on our website.


There’s quite a few other satellites on this launch, and many of them appear to be satellites that could transmit in the amateur bands. We may need some scrambling to get all the frequencies before launch.

EDIT: Magic is happening in the @SatNOGS channel on matrix; frequencies, demodulation and coordination have been collaboratively dug up.


Formatting issues fixed.



BCCSAT-1 is an educational multi-spectral Cubesat 1U developed by the cooperation between Bangkok Christian College and the King’s Mongkut university of technology north Bangkok.

Schedule When our cubesat is completely finished it will be launched into space in March 20,2021 06.07 AM UTC at Russia with the Soyuz-2.1 rocket by UNISAT-7 GAUSS SRL to the low earth orbit at 575 km. and

1 99999U 21999A 21079.53571058 -.00000058 00000-0 00000+0 0 06
2 99999 098.4012 345.1641 0004344 283.2593 155.6823 14.80364805 03

Downlink Frequency
Beacon 435.635 MHz CW
Slow Scan Digital Video SSDV Data 435.635 MHz AFSK 1.2 kbps
Telemetry Data 435.635 MHz GMSK 9.6 kbps

After launch into space if AMSAT member receives the CW signal of BCCSAT-1 satellite. please send information to our team directly an email to:

BCCSAT-1 is a technology demonstration satellite in Thailand. High school students in Bangkok Cristian College in collaboration with King Mongkut’s University of Technology (KMUTNB) and the Radio Amateur Society of Thailand (RAST) are building the satellite.

The project aims to build capacity on systems engineering, space education, and radio communication technology to students. During the project, students will learn about communication technology through amateur radio activities. It also encourages other interested people to receive the satellite signal.

The main missions of BCCSAT-1 include: (1) testing in-house developed satellite transceiver and antenna in orbit (2) experiment of Slow-Scan Digital Video (SSDV) transmission from the satellite (3) take pictures of Earth by cameras onboard satellite

BCCSAT-1 communication subsystem is an in-house developed transceiver and antennas. It has the capability to transmit GMSK modulation signal at 9.6 kbps, FSK for SSDV at 1.2 kbps and receive AFSK signal at 1.2 kbps. The transceiver will send its parameter such as RSSI and temperature to the ground station.

BCCSAT-1 will carry four cameras onboard the satellite and aim to capture images of the Earth in different wavelengths: red, green, blue, NIR, and Red Edge band.

We hope to process the images acquired for the Normalized Difference Vegetation Index (NDVI) and widely used in Science education. The images will be widely distributed among amateur radio community via the experiment of SSDV transmission system and GMSK packets downlink. Moreover, BCCSAT-1 will be able to transmit pre-stored images chosen by high school students.

BCCSAT-1 will provide the multi spectral images by having the total of 5 cameras on board; Red, Green, Blue, NIR, and Red Edge bands. The images we get from these cameras will be used to process for the Normalized difference vegetation index (NDVI), that will significantly provides huge advantage on analyzing the terrain of the country.


Tanan Rangseeprom , HS1JAN

BEESAT-5…8 is part of this launch as well. I’ve just added the details here:

Landing page for LEOP info updates:

SDR decoder:


From this document it looks like both the GFSK downlinks (9k6 and 1k2 AFSK) are using AX.25 framing.
Still no information on packet formats.

I would suggest adding the following transmitters for BCCSAT @ 435.635 MHz (noting this is uncoordinated):

  • CW 20WPM
  • AFSK 1k2
  • GFSK 9k6
1 Like

If these TLEs are correct, they’ll do a West pass over my QTH at around 10:53 UTC, so shortly after starting beaconing :smile:

TU Berlin has updated the timeline and TLE due to the postponed launch. The already mentioned satnogs-ops issue #169 as well as the following URL delivers updates from time to time:

:crossed_fingers: for a successful launch tomorrow.

1 Like

The launch goes for March 22nd:


I’ll try to incorporate custom decoder into my Satnogs station, test IQ-file succesfully decoded ( ).

1 Like

Hi all. These are TLEs calculated by Dmitry Pashkov for GRBAlpha cubesat (launch 22.3.):

1 70009U 21999A   21081.43548380  .00000000  00000-0  00000-0 0    07
2 70009  97.5900 345.0513 0017380 173.0300 122.9932 15.08048476    02
KMSL  (for launch22.03.2021)
1 90017U 21001AR  21081.43902778 0.00000000  00000-0  00000-0 0  9993
2 90017  97.5981 345.6068 0020096 246.9245  68.0617 15.05300826    07

437.265MHz, BPSK 9600 AX.25 G3RUH

1 Like

Thank you for the TLE, the lines didn’t have the right checksum… so here are the fixed ones:

1 70009U 21999A   21081.43548380  .00000000  00000-0  00000-0 0    06
2 70009  97.5900 345.0513 0017380 173.0300 122.9932 15.08048476    03

@hrkim thanks for the TLE and the info.