UMKA-1 telescope satellite mission

Hi. My name is Alexey. I am a member of the UMKA-1 telescope satellite team, we decided to share with the community the main course of our mission and interesting events in the ground segment and a little later the transmission schedule on the S band.
A brief technical note.
UMKA-1 is a school telescope satellite of the 3U+ cubesat format
The payload is a high aperture optical telescope Leptonar-20955K and an astronomical digital camera PlayerOne Saturn-C SQR.

The satellite will operate in two bands.
Telemetry transmission
UHF downlink - 437.625 MHz GMSK USP 2400 bd

Transmission of data from the telescope
Downlink S band - 2402 MHz

The launch and placing into orbit is expected on June 27, 2023.

By the way, the name UMKA is not just an acronym. UMKA is the name of a popular Soviet short cartoon from 1969. It was the name of the polar little bear that became the mascot of our mission. If you have time to watch it. It’s a short touching and kind cartoon.


Hello, dear friends. To successfully receive telemetry and decode the received packets, our team has prepared a commemorative QSL card. Send your reports on accepted packages to the mail in the subject of the letter, specify Recive UMKA, in the report it is necessary to specify - the registered amateur radio call sign (if any), first and last name, time and date of telemetry reception, how the signal was received (describe the receiving equipment and antenna). A little later, for convenience, I will add an application form for the resource

Also, all the necessary information is available on the website of our project Sputnik — Радиолюбителям

Now I am at the Vostochny Cosmodrome. At night after the launch, I myself will sit and peer into the spectrum, waiting for a signal from our “UMKA” and some other interesting spacecraft launched with us. Observations of the spacecraft during the first two weeks are of particular value to the team. Good luck! 73!


The signal is very strong from AOS to LOS in KO02od.
After changing the decoder from GFSK USP to FSK G3RUH everything is OK.



Any CADUs for S band to test decoders with?




Hello Alexey,

many thanks for your interesting report about UMKA-1. I find it very exciting to receive astrometric images with the telescope. Two questions about this:
What is the minimum antenna required for 2.4 GHz?
Are the received images regularly published somewhere?

Thank you and 73


Hello @ upitersaturn09. I was busy and asked a member of our @Foxiks team to answer your question.
He gave an answer in the next topic.

Thank you and good luck. 73!

Hello Josef.
Thank you so much for your interest in our mission. The satellite is currently undergoing testing. The telescope is expected to be put into operation by the end of July.

At the expense of the S-band receiving antenna. We think need a mirror with a diameter of about 2 meters. But it will definitely be clear after the actual broadcast from the telescope to Earth. Perhaps a smaller mirror diameter will suffice.

After the satellite is ready to perform its tasks, a schedule will be published, and an opportunity will also be provided to apply for the transmission of images from the telescope in the planned square.
Thank you and good luck. 73!

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A brief report on the progress of the mission.

Hello dear friends. At the moment, the mission team is in a little work rush, so I don’t have enough time to promptly report on the progress of the mission. But still, I found a little time to inform you about current affairs and plans for the future. As previously reported, due to some fuss and haste, there was a misunderstanding within our team when installing the format and the FSK format was installed instead of the originally planned USP format. And part of our team was not informed about this. But this is our first mission, and given that the bulk of the work on the project is carried out by schoolchildren and students, it is worth honestly admitting that some small shortcomings and omissions took place, for which I apologize in the person of the team. I also want to express my gratitude and appreciation to the guys from SPUTNIX, who supported us and advised us on many issues. I will also add that I saw all the reports sent to our email and will answer them in the very near future. Thank you so much for your interest in our mission.
And so about the plans. In the coming days, we will transfer the telemetry transmission format to USP 2400. There will be an additional message about the format translation. Next, the MCC team will have to work with the stabilization of the spacecraft and the guidance system. After that, work will begin with the payload, which will take about two weeks. Upon completion of payload testing, the telescope satellite will begin its educational mission. I will definitely report this in this topic.
The schedule of work on the S band will be announced additionally.



Hello Aleksey,

Thank you for linking that reply, I didn’t see it!

However, he mentions that there is no baseband yet… is it possible to have the CADU, that is, the data after it is demodulated/deframed?

Best of luck with your mission!


Sasha VE3SVF

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Hello @ jupitersaturn09! You can get a trial CADU file here: cadu_umka_test.rar — Яндекс Диск First you need to use the mixer in the decoder. You need to combine all CADU files into one file, and then open the finished file in the main decoder. At the Exit, you should get a fit file with a photo. The decoder is available on the satellite page!


Thank you so much!!

Ah wait… it’s a rar file…

Would you please be able to send it in a .zip?

Thank you so much!

No problems! — Яндекс Диск


Hello dear friends, the format of the beacon from RS40S UMKA has been changed to GMSK USP 2400 bd

UMKA feels good in orbit in anticipation of flight tests and its main mission.
The application form for receiving a QSL card of receiving telemetry also works.

Have a nice day to everyone!


Here’s my image out of that, reading only VCID 0x41 frames. Not sure what’s wrong.

(plus the multiple references to Adobe are strange… :grin: )

Did you merge both CADU files together? Then just extract the field with useful data throughout the 41 virtual channel and rename the resulting file to and you can open it in GIMP

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Also make sure you are extracting the data correctly! Third party CCSDS demuxers are not suitable for this!

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ah wait, forgot to post it here

I was able to get it a few hours ago after Alan hinted that it wasn’t a raw file but a FITS!

Thanks for the reply anyways!!


Decoder is now here



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