New Satellites Suggestions for db: SiriusSat-1 and SiriusSat-2

Two nearly identical 1U CubeSats are waiting to be deployed from the ISS:

  1. SiriusSat-1 call sign RS13S frequency 435,570 MHz.
  2. SiriusSat-2 call sign RS14S frequency 435,670 MHz.

The modulation is GMSK 4800, AX.25 G3RUH protocol.

Our best info about the deployment time at the moment:

  1. The start of EVA 2018-08-15T15:58Z.
  2. SiriusSats deployment from T+00:10:00 to T+00:18:00.
  3. CubeSats will start to transmit in 15 mins after RBF is removed.
    So our best guess now is they will start beaconing about 2018-08-15T16:23Z every 30 secs.

We’ll post updates on date/time/delays in case of new info.

It’ll be great to get temporary NORAD ids. We are planning to observe first crucial hours/days with help of and Software for telemetry decoding/forwarding and more info on the way.

One more question: As far as we know there is no decoding in 4800 G3RUH mode right now. Would it be hard to add such support? We are ready to write the code and test it. Which way it better be done? Should it be a separate entity like satnogs_fsk9600_g3ruh_ax25 or more generic solution?

Thanks in advance.

– SPUTNIX team | | R2ANF
– Educational Center “Sirius”
– Skobeltsyn Institute of Nuclear Physics(SINP MSU)


Hi sputnix team!

Good luck with your deployment! Currently, there is no GMSK 4800, but your case is a good opportunity to add a series of more generic AX 25 flowgraphs. I will start asap. Meanwhile, do you have any signal recording from your birds to start play with?

Thanks for the info! We are glad to help observing these CubeSats.

I’ve just added SiriusSat-1 and SiriusSat-2 in db and their transmitters. I gave them temporary norad ids, 99970 and 99971.

They will be visible in network in the next hours, however scheduling will not be available until we manually add TLEs (some hours before their deployment). The first TLEs will be the ones of ISS and they will be updated as soon as we have newer ones. After norad id assignment, their TLE will be automatically updated.

Let me know if you have any questions or if you need any help.

Thanks for quick responses. We have uploaded test signal recordings and telemetry decoding software for Windows to our website: We are working on Linux version and more updates. Please let us know if app crashes or any bugs/suggestions or recordings not good.

BTW, what is relations between demoded/decoded telemetry from and submitted through SiDS to Does all telemetry from network go to the db with source == ‘network’ and availiable for download in CSV from Is it possible to relate telemetry received by our network station to our other station(R2ANF-KO85qq at which submits to db through SiDS?

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Not yet. There is a disconnect between telemetry decoded in and telemetry decoded in We are working on a pipeline which will move data from network to db, but for now you may have success finding data in both sources.

Is your telemetry frame data format available somewhere?


Current versions of linked software show bit offsets of all fields in GUI or you can dig straight into resources/devices/*.xml. There is also 8-byte header after AX.25 header, offsets in GUI and *.xml are from the end of that extra header. Only beacon descriptions translated to English ATM. We don’t provide more descriptions of data formats right now, but we can help and answer questions. If you are thinking about parsing telemetry for web interface it’s probably an overkill in case satellites fail.

Thanks for clarifications about network/db matter.


I decoded your IQ recording. So I proceed adding the proper flowgraphs in the gr-satnogs,


Thanks. Just in case, SSIDs of the satellites is 1 and 2 respectively, not zero. We were using SSIDs to identify them before they’ve got their own call signs. We doubt that matter, but just FYI.

We should probably get the TLEs entered (ISS initially I presume) so we can start scheduling observations for Tuesday starting at 16:00 UTC.

It seems NASA TV will broadcast the EVA live

Hey @KU2Y,

I guess you mean Wednesday 2018-08-15 at 16:00UTC, unless I miss something.

I’m going to add ISS TLE to those two on Tuesday UTC night in order to get the most recent ISS TLE.

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Oops! I’m a day off! Yes, Wednesday is the deployment day, so adding them Tuesday night is best. Thanks as always!


Linux version of telemetry decoding software is available on our site now. If there are any bugs or crashes we will try to fix it. Any questions or contact reports are welcome to email siriussat ta sputnix.

If you know people who can help us observing first days please share info with them. Both network.satnogs people and all others are welcome.

There is some info that satellites could be deployed some minutes later. Which can make the first North America pass silent. But it’s better to start early than later. Watch live, good luck with reception! We believe in you!


First 24 hours of observations are scheduled starting at 1600.

If I have a chance I might try to listen in to see if I can hear the EVA VHF communications:

Best of luck to everyone for a successful deployment! :slight_smile:

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SiriusSat-1 has been seen:

SiriusSat-2 has yet to be seen, and per request from @sputnix on irc/matrix I’m going to change a couple of the siriussat-1 observations to siriussat-2 (fyi @KU2Y)


That is a very good idea. Also feel free to steal observations from the Tanusha’s as at least one has been seen already.

Is there a signal from SiriusSat-2 in this observation?
There are a couple of weak lines, but I can’t hear them in the audio.

I don’t think so with the way those blips follow the noise line…

if it was beaconing I should have heard it on this pass, it was right in the open air for me… alas, nothing :frowning:

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Blast form the past :slight_smile:

As both SiriusSat-1 and Siriusat-2 are ready to decay in the next couple of days, @pierros by using strf toolkit generated TLE set for each of them:

1 43595U          20335.29166667  .00000000  00000-0  56251-3 0    07
2 43595  51.6120 148.3405 0009780 241.5191 299.8621 16.05928926    00
1 43596U          20335.29166667  .00000000  00000-0  57179-3 0    08
2 43596  51.6474 149.2366 0009621 154.5756 338.0304 16.08868853    02

New TLE sets:

1 43595U          20336.29166667  .00000000  00000-0  56251-3 0    08
2 43595  51.6120 142.9529 0010340 229.9422 341.2143 16.08667192    07
# 20201201.20-20201201.27, 11 measurements, 0.091 kHz rms
1 43596U          20336.29166667  .00000000  00000-0  57179-3 0    09
2 43596  51.6244 143.8235 0005714 218.2092 303.5710 16.08057611    02
# 20201201.21-20201201.27, 22 measurements, 0.072 kHz rms

We’ve tried the second TLE set 2020-12-02. It was better than AMSAT/CelesTrak/SpaceTrack/NORAD. Thanks a lot! Then TLEs got updated again, and now they are old again. We hope to get new TLEs for tomorrow 2020-12-05 Moscow passes. Any help much appreciated!

There are a lot of experiments going on with sats these days, hope you all understand. We are swamped with upcoming launches to be honest, but we hope to get back in touch with SatNOGS, IARU and all RF/amateur/sat community soon!