BLUEWALKER-3 & BLUEBIRD1-5 (AST)

1st Official Post
    • Official Post

    BlueWalker 3 (BW 3) is a ~1.5 Ton commercial satellite from AST & Science's SpaceMobile, meant for 4G/5G mobile communications constellation, is obviously transmitting in the "amateur satellite service" band on 437.500 MHz :thumbdown: for TT&C (Space-to-Earth).


    The BW3 satellite will operate under network filings made on behalf of AST with the ITU by the Papua New Guinea administration under the name MICRONSAT. --> 265582.pdf


    see also: https://db.satnogs.org/satellite/99330

    • Official Post
    Quote from DG8KD

    Hat diese absichtliche (?) Miss-Nutzung irgendwelche Konsequenzen für den Betreiber?

    Moin Rainer,


    ich fürchte nicht, offensichtlich ist man da mit ja durchgekommen.. und wo kein Kläger... IARU?


    Spätestens zum Jahresende werden wir es wissen, dann sind mehre Nachfolger geplant... vielleicht hat sich hinter den Kulissen etwas getan...


    73s Peter

    • Official Post

    Hallo Rainer


    Das ist ein uraltes Thema. Das Problem ist, dass das 70cm-Band keine Primärzuteilung für Amateurfunk hat. Da tummeln sich unzählige CubeSats im Orbit, die mit Amateurfunk nichts am Hut haben aber unsere Frequenzen nutzen, weil sie gratis sind. Kommerzielle Lizenzen wären für diese Betreiber zu teuer. Universitäten werden geduldet, weil sie einen Lehrauftrag haben. Im Amateurfunk lernen wir ja auch ständig dazu.


    Die IARU hat keine ausführende Macht, sie koordiniert lediglich unsere Frequenzen, da Amateurfunk bekanntlich ein sich selbstregulierender Funkdienst ist. Aber auch da werden für eine Sat-Frequenz oft keine richtigen Angaben für eine Koordination gemacht. Das Ganze bewegt sich ständig im Graubereich. Ausnahmen bestehen da, wo sich AMSAT-Gruppen mit einer eigenen Nutzlast wie Repeater, Digipeater, Transponder usw. beteiligen können.


    73

    Nach ein wenig Suche im offenen I-net (twitter) gefunden.

    Die Lizenz im 70cm Amateurfunkband verfällt am 24.05.2023.

    Ob die nächsten 5 Satelliten, die bis Ende 2023 gestartet werden sollen, wieder die 437.500 MHz nutzen werden, konnte ich noch nicht in Erfahrung bringen.


    Hier der Versuch einer Erklärung, wieso auf BW-3 diese Frequenz/Modulation nutzt:


    "A month ago, I looked at the UHF packets and checked that BlueWalker 3 used exactly the same modulation and coding as Light-1, which is a 3U cubesat from United Arab Emirates (this was first discovered by Tetsurou Satou JA0CAW). The framing contains the typical elements of the built-in packet handler of low cost FSK chips such as the Texas Instruments CC11xx family. Scott Tilley noticed some details that seem to explain this connection: Light-1 was built by NanoAvionics, which apparently has collaborated with AST SpaceMobile in the BlueWalker 3 mission. Therefore, it seems that the satellite bus used by BlueWalker 3 is that of a typical cubesat."

    Decoding the BlueWalker 3 S-band downlink – Daniel Estévez (destevez.net)

    Danke für den Screenshot.

    Quelle?

    Eigentlich sollten die Mobilfunksender beim Überflug über Deutschland aktuell ausgeschaltet sein, der Überflug erfolgt aktuell einmal in der Nacht über DL.

    Die offizielle Testphase für den Mobilfunkbetrieb in den Staaten startet vorauss. Ende des Monats.

    • New

    SpaceX just launched 5 Block 1 BlueBird satellites for AST’s constellation and like Bluewalker-3 they will transmit in the 435 MHz amateur satellite band.


    Although FCC confessed that the commercial 435 MHz TT&C operations do not fall within the ITU assigned classification for the amateur satellite service, they granted permission…


    See FCC extract below:


    Page 7:

    14. UHF Band. AST also seeks to conduct TT&C in the 430-440 MHz (space-to-Earth and

    Earth-to-space) band outside the United States, including for LEOP, with five satellites authorized in this

    grant. AST plans to perform such operations pursuant to agreements with authorized third-party teleport

    operators. The International Table of Frequency Allocations has allocations for amateur, radiolocation

    and Earth exploration-satellite services in the 430-440 MHz band. However, there is no relevant service classification for AST’s TT&C operations. Accordingly, AST submitted an interference analysis to demonstrate that it will not cause harmful interference to other operations in conformance with the ITU Radio Regulations. When operating in the 430-440 MHz band, AST shall not cause harmful

    interference to, and shall not claim protection from harmful interference caused by, a station operating in

    accordance with the ITU Radio Regulations. Furthermore, in the unforeseen and unlikely case that

    harmful interference occurs, AST confirms that it is capable of ceasing transmissions from its satellites as

    required under section 25.207 of the Commission’s rules, and consistent with notification of a non-

    conforming frequency use, which requires that any harmful interference be eliminated immediately. We

    conclude that AST’s demonstrations are sufficient to authorize a limited, non-conforming use, and

    therefore grant AST authority to conduct TT&C operations in the 430-440 MHz band with earth stations

    outside the United States, including during LEOP, subject to the laws, regulations, and requirements

    applicable to such operations in any foreign jurisdictions.


    Page 13:

    In its most recent amendment, AST requests to operate five additional satellites at a lower

    altitude and added requests to operate in the S-band and UHF band for TT&C during LEOP and

    emergency TT&C. Although submitting these additional requests could be considered a “major”

    mendment under our rules these requests do not create the potential for new or increased frequency

    conflicts, and AST does not seek to make any changes to its previously requested V-band operations.

    Also, no other processing round participants commented or expressed concern on AST’s request for an

    additional five satellites or TT&C frequencies.


    Page23: Groundstations

    UHF band: 430-440 MHz (Earth-to-space) (space-to-Earth)

    1. Wilde, Argentina
    2. Perth, Australia
    3. Vinogradets, Bulgary
    4. Knoll Fort, St. Helena
    5. Juju, South Korea
    • New

    Satellites have been added in SatNOGS DB with transmitter based on bluewalker 3 one at 437.500 MHz.

    A TLE set has been generated to track them, it is not fully accurate but it should work for the first observations:


    Bluebird 5

    1 98800U 24256.37291667 .00000000 00000-0 50000-4 0 07

    2 98800 53.0000 22.1000 0010148 0.0000 22.3000 15.15323704 02

    Bluebird 4

    1 98801U 24256.37291667 .00000000 00000-0 50000-4 0 08

    2 98801 53.0000 22.1000 0010148 0.0000 22.3000 15.15323704 03

    Bluebird 3

    1 98802U 24256.37291667 .00000000 00000-0 50000-4 0 09

    2 98802 53.0000 22.1000 0010148 0.0000 22.3000 15.15323704 04

    Bluebird 2

    1 98803U 24256.37291667 .00000000 00000-0 50000-4 0 00

    2 98803 53.0000 22.1000 0010148 0.0000 22.3000 15.15323704 05

    Bluebird 1

    1 98804U 24256.37291667 .00000000 00000-0 50000-4 0 01

    2 98804 53.0000 22.1000 0010148 0.0000 22.3000 15.15323704 06

  • DB2OS

    Changed the title of the thread from “BLUEWALKER-3” to “BLUEWALKER-3 & BLUEBIRD1-5 (AST)”.
    • New
    Quote from HB9SKA

    But the 70cm band is not exclusively reserved for amateur radio like the 2m band.


    Yes and No! There are "non-amateur-radio" satellites, but still "amateur" and non-commercial according to the ITU regulations.. (see thread above).




    However, BlueWalker and BlueBird satellites do not fall into any of the categories assigned to the 430 MHz - 440 MHz Band. Thus, they should not be there.. and even more funny, FCC allowed them only to transmit outside of US, as long as nobody complains..

    So not only satellites, but also EME, SSB and others will be affected too.. and this may only be the beginning and a forerunner of hundreds and thousands to follow, if nobody cares. And if ham radio community does not care, it probably deserves it..


    BTW: SpaceX Starlink satellites are using 137 MHz frequencies for a similar purpose. Why can't AST just do it like everyone else is doing?

    • New

    Hallo Peter


    This is a very old problem with the beginning of the deploying of the CubeSats. The IARU does a difficult job to distinguish, which satellite is commercial and which is not. And many CubeSats are coordinated, but in the "Grauzone".


    We had russian satellites with DOKA-B downlinks and so forth. There is a good intuder watch for our shortwave bands, why not for our UHF/SHF bands ? Galileo was an exception. A concrete threat of our frequencies must always occur before we react.


    SpaceX beansprucht 71 - 86 GHz

    [02.24] Für die ca. 30'000 der vorgesehenen Starlink-Satelliten liegt ein Antrag bei der US-Behörde vor. Geplant sind insgesamt 42'000 Satelliten. Es ist nicht klar, in wie weit damit das 76-GHz-Band der Funkamateure tangiert wird. Dieses umfasst laut IARU-Bandplan den Bereich 75.5 - 81.5 GHz. (USKA)



    The threats continues...