Re-post from ANS:
The public comment period has officially closed for FCC Space Bureau Docket 25-201, which reviewed a request by AST & Science, LLC (AST SpaceMobile) to use the 430–440 MHz band for telemetry, tracking, and command (TT&C) operations. This spectrum includes 435–438 MHz, a critical allocation for the amateur satellite service. The filing window ended at midnight Eastern Time on July 21.
AMSAT submitted formal comments opposing the proposal, citing the extensive non-commercial use of 435–438 MHz by amateur satellites, including OSCAR-class spacecraft, educational CubeSats, and the ARISS station aboard the International Space Station. AMSAT also highlighted ongoing interference caused by AST’s BlueWalker-3 satellite on 437.500 MHz, which has disrupted InspireSAT-1. The filing urges the Commission to deny AST’s request and preserve the integrity of the amateur satellite service.
The international amateur satellite community also responded forcefully. AMSAT-DL (Germany) provided direct evidence of BlueWalker-3 interference received at the Bochum Observatory. AMSAT-SM (Sweden) filed in opposition as well, and the International Amateur Radio Union (IARU) pointed out that AST’s use of 430–440 MHz under ITU Radio Regulation Article 4.4 lacks required sharing studies and would pose significant interference risks to amateur operations worldwide.
As of the close of the comment period, the FCC docket recorded 2,283 total filings, a remarkable outpouring of concern from the amateur community. While not all filings were express comments in opposition, the overwhelming majority appear to be from individual amateur radio operators urging the FCC to reject AST’s request. The ARRL encouraged its members to participate. The result is one of the most heavily commented amateur-spectrum proceedings in recent FCC history.
AMSAT’s submitted comments to the FCC on Docket 25-201 regarding 430–440 MHz spectrum use. (Click image to view the full filing)
AST has maintained that its use of the band would be limited to early-orbit phases and emergencies, but commenters—including AMSAT—argue that such “limited use” does not mitigate the real potential for interference. AMSAT emphasized that many amateur satellites rely on IARU-coordinated use of 435–438 MHz, and that commercial systems should operate in bands explicitly allocated for space operations—not shared amateur satellite spectrum.
The FCC’s reply comment window remains open through August 5, 2025. During this period, individuals and organizations may respond directly to previously filed comments, clarify technical concerns, and reinforce the case for preserving amateur access to 435–438 MHz. AMSAT encourages reply commenters to cite interference data, highlight educational and non-commercial uses, and support the formal filings made by AMSAT and IARU.
After the reply deadline, the FCC Space Bureau will review the entire docket record. This process may take weeks or months and may culminate in a proposed order or public notice. While there is no petition-to-deny window in this particular docket, stakeholders may still file additional comments or seek reconsideration if the Commission issues a preliminary decision.
AMSAT will continue to monitor the proceeding and work in coordination with the IARU and international partners to protect amateur satellite spectrum. The 435–438 MHz allocation remains a cornerstone of AMSAT’s mission to promote education, experimentation, and global collaboration in space communications. AMSAT thanks all who filed comments and urges continued engagement as the proceeding advances.
[ANS thanks AMSAT and the FCC Electronic Comment Filing System (ECFS) for the above information]
