Can you hear SamSat-218D?

Students of the Samara State Aerospace University are having trouble getting a signal from their satellite, SamSat-218D. They are now reaching out to the radio amateur community, inviting everybody with sufficiently sensitive UHF VHF band (144 MHz) equipment to help by listening to SamSat-218D. The satellite was entirely built by students and went into space on board of a Soyuz-2 rocket on April 26, 2016. This is their call (translated by Google):

“To all radio amateurs who have the ability to receive signals from satellites in the UHF VHF band (144 MHz).

April 28 during the first launch from the Baikonur East satellite SamSat-218D was launched, created by Samara State Aerospace University.

The satellite beacon, which transmits every 150 seconds (or 30 seconds), the word “SamSat-218D” for 15 seconds at a frequency of 145,870 MHz. The transfer is carried out in Morse code in the CW mode. During the passage of the satellite over our receiving station we hear fragmentary Morse code in background noise, but not sure of the extent of its authenticity.

We ask to listen to broadcast on the aforementioned frequency, record audio and send e teomant@bk.ru. For all matters relating to the reception, ready to provide additional information, if necessary. Handling large amounts of data will allow us to understand the nature of the problem (possibly satellite heavily spun at the exit of the transport and launch container) and try to estimate the rate of rotation “

 

SamSat-218D flies in a polar orbit, and according to the tracker on N2YO.com, it is currently over the Pacific, and should soon reach Europe. The rocket, a Soyuz-2.1a, which carried SamSat-218D and two other satellites, was also the very first launch from the new Vostochny Cosmodrome. So, while you wait until the satellite flies over your region, you may enjoy the launch video below.

This task is perfect for a network of satellite ground stations. We’ve reached out to the SatNOGS team, winners of the 2014 Hackaday Prize, to see about adding this satellite to the network’s listening schedule.

Thanks [Ivan] for the tip!

44 thoughts on “Can you hear SamSat-218D?

    1. Quite right.

      Interesting, I wonder if the Google translation is getting this wrong or if the original has the mistake too. Can anyone tell me what the proper translation is for this:

      в УКВ диапазоне (144МГц)

      1. No wonder, the Soviet standard for УКВ goes from 30 megaherz to teraherz ranges. And I think we have adopted the standards here in Russia.

        But it is VHF anyway, 144 MHz is in the VHF range and both Multitran and Wikipedia say that УКВ corresponds to VHF.

      2. There is mistake in translate because in Russia we have name «УКВ/МВ» for VHF, «УКВ/ДМВ» for UHF and «УКВ/СВЧ» for SHF, but in practice they all named «УКВ» and translates automaticly to UHF

  1. Don’t write [SIC!!] when the original doesn’t say that UHF. The original text says УКВ, which is the VHF band. Are you trying to make the russian students look like amateurs when the mistake is either in Google’s shitty translator or your in own incompetence for not checking (took me a whopping 10 seconds)?

  2. Of course, once upon a time “UHF’ started about 28MHz, ie 10metres. Originally the VHF column in QST covered that band. The icky “UHF connector” dates from that time useful for those lower frequencies which were cutting edge at the time, but the connectors not so useful for much of the VHF segment and even worse at UHF.

    Michael

      1. I’ve had great experience getting data from weather satellites using crossed dipoles, so I can only recommend that ;)
        I might try listening in on this one too (if it hasn’t passed yet, haven’t looked at the schedule yet).

  3. SamSat may be object 41465 NOT 41466
    http://www.n2yo.com/?s=41465

    What happens is numbers are assigned to objects tracked, but they are not sure which cubesat is which object. Only by carefully checking the broadcast signal and Doppler they can identify which object is which transmitter and so assign the correct number to the correct object. In reality to help with the problem you need a beam antenna with a software defined radio so you can record the complete pass and signal. As suggested the satellite may be OK, but spinning so much the antenna may be bent or directional but spinning so average power towards earth is much lower.

    Reference to data:
    Dmitry, R4UAB, published further information on SamSat 218D and
    Aist 2D. It appears RS 48 is Aist 2D (object 41465, 2016-026B) instead
    of SamSat 218D. This is now confirmed by doppler measurements.

    An overview of all downlinks:

    Aist 2D (‘Stork’ 2D) / RS 48
    * 435.315 MHz telemetry and digital data
    * 435.365 MHz telemetry and digital data
    * 8025 – 8393 MHz remote sensing digital data
    * 433 – 438 MHz P-band radar

    SamSat 218D
    * 145.850 – 145.890 MHz transceiver TRXSSAU downlink

    There is an update on Dmitry’s log saying he heard nothing from the satellite today (needs translation)
    http://r4uab.ru/
    He suggests the ‘owners’ may have just heard a weak signal from one of the many other satellites in space.
    He compares the time of the report to possibly another satellite that may have been heard.

    So possibly it is not transmitting at all? If it is not transmitting then it is harder to identify which object it is, and so point antennas at the correct object. Over time all the cubesats launched will separate more from each other meaning you need to decide which one to direct your antennas at.

    It is quite common for cubesats to fail, due to many possible reasons.

      1. If you heard it from Fort Worth TX then it must be transmitting. Did you hear this CWID? https://soundcloud.com/user770178867/mp-572ba2acade7a (it is set at 5wpm not sure how fast they set theirs). Reading their page they are pretty frustrated with this. They claim they can hear a PRC nanosat just fine near the horizon. Can’t figure out why they can’t hear SamSat218D. And they are aware of Doppler shift. If in fact you can hear it from TX (CONUS) then maybe they have deliberate QRM on their end? Just an idle speculation on my part. But who would do that?

  4. Since the UHF error is in the original text… could there be any additional errors unseen as yet? Are the students aware of Doppler shift with orbiting transmitters? Has anyone tried to use an Internet remote receiver on this frequency? Usually the station attendants/operators have erected very good antennas with sensitive receivers (i.e. DXZone).

    1. I am sure the students are aware of doppler. Lots of people are working on this. There is dozens of amsat people with amazing set ups. Many have very good set ups and routinely identify and catalogue launches of dozens of cubesats. The UHF/VHF is just a literal translation problem where the russian for “above HF” is automatically translated to UHF, but the correct translation is VHF/UHF band.

      http://r4uab.ru/ is a good source of quality information and he has a web SDR anyone can use. Ideally you need a highly directional antenna with a masthead mounted pre-amplifier coupled to a software defined radio. Anything less is not really worth the effort, as it will only provide vague answers. Most web SDRs are omni directional and only really sensitive to objects at high elevations.

  5. Sadly no most hams CANT hear it because most radio makers hate anything but FM in the Ham radio VHF/UHF bands. in fact right now short of very high end HD all mode radios there is NOTHING available to receive 2 meter CW.

    Older radios were capable. my cheap old Ft-817ND can do it, but it is a QRP HF rig that happens to go into the 2 meter band. And it cost $900 when new, out of reach for 75% of ham radio operators.

    1. I have atleast 5 radios that works 2m SSB, and I wouldn’t say it is that uncommon.(I also have a 817, 857 and 847, a TR751 and another allmode 2m Kenwood)
      I also have 2×15 el X yagi, sadly those are packed away and not in the tower at the moment.

    2. I heard the satellite today on my ICOM IC-7000 mounted in my car with a Diamond HV7 vertical antenna on the lift gate. The 7K does all modes on all bands.

  6. Is this yet another satellite they designed to spin about the longitudinal axis? There is no such thing as an ideal rigid body, so rotational kinetic energy dissipates in bending/moving of the satellite parts, until its rotational kinetic energy has dissipated into heat (without losing angular momentum) such that it invariably rotates along the axis with highest moment of inertia…

    1. look up construction of Poinsot, Goldstein describes it, and there are animations of the ellipsoid of inertia, the invariable plane, and the sphere of rotational kinetic energy online…

    2. also to clear up my original comment, it shows how easily the eventual axis of rotation -after spontaneous dissipation of dissipatable rotational kinetic energy- differs from the intended design axis of rotation. In designing a sattelite this should be an important consideration, and only let it spin about the long (low moment of inertia) axis if absolutely unavoidable (even if you have long telescope tube, consider the possibility of using a 45 degree mirror).

      1. if you are afraid this makes your picture of the target rotate about the center of the picture, simply use a second 45 degree mirror for the “ocular”…

    3. and next time you design a satellite, walk the halls of the closest universities and ask any mechanics professors in engineering/physics/math departments if they have heard about “geometrical mechanics”, if their eyes light up include them in the design of the next satellite…

  7. ” 433 – 438 MHz 200 watt Synthetic Aperture Radar (SAR) !!! ”

    A small 200W radar in 70 cm band. That’s a beauty!.

    https://amsat-uk.org/2016/04/30/aist-2d-and-samsat-218/

    I hope i never heard of tis bird and other like this. How in the hell IARU admit non ham transmission in special aperture radars in ham bands. Ham radio bands are not free. We take exams and pay licenses for use this bands in regulary trafic and experiments in legal limits. We put a lot of satellites using VJF/UHF transporders with power less 2.5 Watts and we invest in a lot of ground equipement like repeators, beacons etc and most of them are working in this stupid 200w aperture radar range. People from universityes, you have a lot of unused frequencyes all arround so let us alone.
    I think we start question about lidership of IARU, i think they represents other interests. not amateur radio.

    1. 433.05 MHz to 434.79 MHz is an ISM allocation in ITU Region 1 (which Russia belongs to).
      As this is a university sat, it would fall into the scientific part of ISM also allowed to use higher power.

  8. The current ITU Radio Regulations permit 432 438 MHz for use by Earth exploration satellites in all 3 regions.
    Amateur Radio only has “co-primary” status to Radiolocation in Region 1, and is secondary in other regions.
    It is probably pointless trying to argue with the primary users of spectrum.

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