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 serviceclassification for AST’s TT&C operations. Accordingly, AST submitted an interference analysis todemonstrate that it will not cause harmful interference to other operations in conformance with the ITURadio 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.
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.
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
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 serviceclassification for AST’s TT&C operations. Accordingly, AST submitted an interference analysis todemonstrate that it will not cause harmful interference to other operations in conformance with the ITURadio 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…
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.
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.
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.
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.
