AST's BlueBird 1-5

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

DA-24-756A1.pdf (416.7 KB)

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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
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Two signals found over Europe 12-09-2024 10:46 UTC pass

On 434.100

Fitting the preliminary TLE

1 98800U          24256.37291667  .00000000  00000-0  50000-4 0    07
2 98800  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    04
# 20240912.45-20240912.45, 21 measurements, 0.030 kHz rms

On 435.900, the same correction as the signal on 434.100

The search continues

Jan - PE0SAT

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Based on @PE0SAT’s analysis above here are the updated TLE sets:

Bluebird 5
1 98800U          24256.37291667  .00000000  00000-0  50000-4 0    07
2 98800  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    04
Bluebird 4
1 98801U          24256.37291667  .00000000  00000-0  50000-4 0    08
2 98801  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    05
Bluebird 3
1 98802U          24256.37291667  .00000000  00000-0  50000-4 0    09
2 98802  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    06
Bluebird 2
1 98803U          24256.37291667  .00000000  00000-0  50000-4 0    00
2 98803  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    07
Bluebird 1
1 98804U          24256.37291667  .00000000  00000-0  50000-4 0    01
2 98804  53.0000  21.8207 0010148   0.0000  42.4374 15.15323704    08

Also I’ve updated the first three of them at 434.100 MHz and the other two at 435.900 MHz until we find the rest of the frequencies.

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That FCC document (from https://docs.fcc.gov/public/attachments/DA-24-756A1.pdf) does list specific frequency assignments (with restrictions) for as-needed TT&C:

2225 MHz and 2235 MHz, each with bandwidths of 768 kHz (space-to-Earth)

and

430.5 MHz, 432.3 MHz, 434.1 MHz, 435.9 MHz, and 439.5 MHz, each with bandwidths of 50 kHz

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Thanks Scott,

I just fell off my chair after reading the UHF frequencies and it also explains why I didn’t receive the other satellites.
My scan was between 434 and 438 MHz.
How is it possible that they got permission.

Included in the FCC ruling:

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

More important:

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.

The FCC should have never granted this, it’s an infringement.
I guess the “interference analysis” is based on Bluewalker-3, where probably nobody complained…

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I am flabbergasted, why do we even have regulations.

This will harm EME, repeaters and the basic agreements made by organisations.

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I’m almost sure that I’ve seen observations in Network of Bluewalker-3 interfering with other radio amateur satellites. But indeed I don’t think anyone complained, however this shouldn’t be an excuse.

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The are the first TBA (To Be Assigned) TLE sets from space-track:

0 TBA - TO BE ASSIGNED
1 61045U 24163A   24256.51590127 -.00000318  00000-0  00000+0 0  9993
2 61045  52.9780  21.1720 0012011 319.8387 143.4316 15.16983313    20
0 TBA - TO BE ASSIGNED
1 61046U 24163B   24256.52068642 -.00000319  00000-0  00000+0 0  9998
2 61046  52.9805  21.1644 0012195 324.5046 165.0051 15.17191184    15
0 TBA - TO BE ASSIGNED
1 61047U 24163C   24256.52142675 -.00000316  00000-0  00000+0 0  9995
2 61047  52.9798  21.1566 0009510 335.1222 158.4448 15.16530970    16
0 TBA - TO BE ASSIGNED
1 61048U 24163D   24256.51992553 -.00000320  00000-0  00000+0 0  9998
2 61048  52.9793  21.1510 0011796 328.7478 156.7243 15.17517352    15
0 TBA - TO BE ASSIGNED
1 61049U 24163E   24256.51992265 -.00000321  00000-0  00000+0 0  9990
2 61049  52.9794  21.1588 0012751 334.9506 150.5679 15.17681074    13
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For anyone curious about the downlink packets showing up on those 400 MHz freqs, I finally got around to replaying a recording from this morning.

They are 2k4 FSK w/ ‘Light-1’ framing. Here are a few of the frames; didn’t see any ASCII or anything of interest.

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I wonder who the processing round participants were for this? Would the ARRL have been involved?

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It’s no secret that BlueWalker 3 was a NanoAvionics cubesat from Lithuania with a huge foldable antenna attached. These new satellites seem to be the same. They even use the same protocol on UHF.

The reason they’re preferring UHF instead of S-band for TTC is that they got zero complaints for requesting UHF. In S-band uplink you often get lots of complaints from NASA. You can see all the limitations they’ve gotten in this grant related to avoiding interference to NASA satellites.

Reading the FCC grant carefully, it is clear that the UHF grant is only for communications with the 5 groundstations (all outside the US!!) listed at the end of the document. The grant doesn’t allow continuous beaconing as they’re doing!!

The major point is that AST are transmitting over the US on UHF, which shows that they’re even not at all following what the FCC grant says. Perhaps because they think nobody will observe and complain. In this respect, the FCC might want to find them or at least call them to order. ARRL/AMSAT-NA are the best to complain by providing evidence collected by SatNOGS because they’re US entities.

Even though doing TTC with 5 particular groundstations in amateur spectrum still seems unfair, continuously beaconing worldwide (and with a rather high duty cycle) is orders of magnitude worse.

Observations using SatNOGS seem to be constantly beaconing, including inside the US (example: SatNOGS Network - Observation 10234701).

It might be reasonable to fill in a complain with the FCC. Primarily though AMSAT NA and/or ARRL, but all other’s like AMSAT-UK / RSGB, AMSAT-F, AMSAT-HB, DARC, etc… should also act accordingly. AMSAT-DL is already in touch with DARC and IARU.

It’s strategically important for amateur radio, to act strong as a community in this case. If this slips without consequences, then it sets precedent for more cases of the same, whether it’s all the future 243 AST satellites, or someone else’s.

Please act!

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How does one “act” towards these non technical civil servants?

I have no idea what kind of language I should use towards these organisations ?

Jan - PE0SAT

I’m sure this is far from the ONLY method, but perhaps one way to start:

https://consumercomplaints.fcc.gov/hc/en-us/requests/new?ticket_form_id=38844

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Bluebirds have been now updated in DB with their NORAD IDs and naming based on https://celestrak.org/NORAD/elements/gp.php?INTDES=2024-163.

As we don’t know how celestrak got the naming, this may change in the future. Our previous naming was based on sorting the frequencies from lower to higher while clestrak’s one (and the one we changed to follow) is the opposite, frequency ordered from higher to lower.

Anyway, even if the naming isn’t right, we track the right NORAD IDs for the right frequencies, so it will be an easy fix in the future if naming isn’t the right one.

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