Partial Victory in 430-440 MHz Band Defense
The amateur radio community has achieved a significant but limited victory in protecting the 430-440 MHz band from commercial satellite encroachment. AST SpaceMobile’s request for broad commercial use of amateur spectrum has been restricted to emergency-only operations for a maximum of 24 hours and only 20 satellites—but the fight isn’t over.
AST SpaceMobile (AST & Science LLC) operates a constellation of large commercial satellites designed to provide cellular service directly to mobile phones. Think of it as trying to turn satellites into massive cell towers in space. The problem? They wanted to use the 430-440 MHz amateur radio band for their Telemetry, Tracking, and Command (TT&C) operations across a planned 243-satellite constellation.
This isn’t just about frequency coordination—it’s about fundamental spectrum philosophy. The amateur bands exist for experimentation, emergency communications, and education. Commercial operations fundamentally change the character of these allocations, much like turning a public research laboratory into a private factory floor.
The Technical Challenge
AST SpaceMobile’s satellites are massive. These are some of the largest commercial satellites ever deployed, with solar arrays spanning over 700 square meters. These aren’t small CubeSats doing modest experiments. They are industrial-scale infrastructure requiring robust command and control systems.
The company initially deployed five Bluebird satellites in September 2024, operating on amateur frequencies at 430.5, 432.3, 434.1, 435.9, and 439.5 MHz with 50 kHz bandwidth. These were launched and operated without proper authorization. Each planned satellite would require TT&C channels with bandwidths between 64 – 256 kHz, creating a significant interference footprint across the entire 10 MHz amateur allocation.
The Open Research Institute, along with numerous international amateur radio organizations, filed strong opposition to AST SpaceMobile’s request. Our argument was both technical and philosophical:
Summarized from our filed comment, the technical objections included the following.
1) Multiple established commercial satellite bands exist (S-band: 2025-2110 MHz, X-band: 8025-8400 MHz, Ka-band: 27.5-30.0 GHz)
2) ITU studies specifically excluded the 430-440 MHz amateur allocation from commercial TT&C considerations
3) Modern satellite technology readily supports operations in higher frequency bands with better propagation characteristics. 430-440 MHz is not the best choice.
We raise the following philosophical and cultural concerns.
1) Amateur radio bands serve critical emergency communications when commercial infrastructure fails
2) These frequencies support STEM education and technological innovation. Where do you think many RF engineers get their start?
3) Commercial encroachment sets a dangerous precedent that could completely destroy the experimental character of amateur allocations
The FCC’s Decision: A Limited Victory
On August 29, 2025, the FCC issued a modified grant that significantly restricts AST SpaceMobile’s operations:
1) 24-hour limit. TT&C operations in the 430-440 MHz band are permitted only for periods not exceeding 24 hours.
2. Emergency only. Operations are restricted to Launch and Early Orbit Phase (LEOP) and emergency situations when no other band is available.
3. 20-satellite cap: Authorization covers only the next 20 satellites, including the FM1 prototype.
FM1 stands for “Flight Model 1” and is AST SpaceMobile’s first “Block 2” BlueBird satellite. It’s a much bigger, more powerful version of their current satellites. According to AST, it is about three times larger than their first-generation BlueBird satellites with 10 times the capacity. Launch dates have been delayed over the past year and the satellite might go up in early 2026.
This represents a major step back from AST SpaceMobile’s original request for blanket commercial access across their entire constellation.
What Does This Mean for the Amateur Community?
The decision validates several key principles that we and many others have been patiently asserting to regulators.
1) Amateur spectrum is different. The FCC acknowledged that amateur allocations can’t simply be treated as general-purpose commercial spectrum. The severe restrictions imposed recognize the unique character and public service value of amateur radio.
2) Technical alternatives exist. By limiting operations to emergencies “when no other band is available,” the FCC effectively endorsed our argument that commercial TT&C bands are technically viable for these operations.
3) Precedent matters. While it shouldn’t have to be repeatedly argued, precedent really does matter and vigilance is required in order to keep a solid regulatory foundation for amateur radio. Rather than opening the floodgates to commercial use of amateur spectrum, the FCC imposed strict limits that discourage similar requests from other operators.
Industry Response and Next Steps
AMSAT-DL described this as a “greater (partial) success” for amateur radio and AMSAT satellite operators. The 24-hour emergency-only restriction and 20-satellite cap should give AST SpaceMobile sufficient time to redesign their constellation for proper commercial frequency usage.
However, this isn’t a complete victory. AST SpaceMobile still has temporary access to amateur spectrum, and the company may seek to extend or modify these restrictions as their constellation develops.
Lessons for Open Source and Amateur Communities
This case illustrates several important principles for defending community resources. Documentation matters. Technical arguments backed by ITU studies, engineering analysis, and regulatory precedent carried significant weight in the FCC’s decision. Without this, things would have worked out very differently.
Community coordination works. International amateur radio organizations presenting unified opposition demonstrated the global impact of spectrum decisions.
Vigilance must continue. Protecting community resources, whether spectrum, software licenses, IP addresses, or technical standards, requires continuous engagement with regulatory and governance processes.
The amateur radio community must remain vigilant as commercial space operations continue expanding. AST SpaceMobile’s modified authorization creates a framework for emergency use that other operators will definitely seek to exploit.
We encourage continued support for organizations like AMSAT-DL, ARRL, and the Open Research Institute that actively defend amateur spectrum rights.
You can participating in FCC comment periods on spectrum issues. Yes! You! Reach out to your local amateur radio organization and be part of the process. Support technical education that demonstrates amateur radio’s ongoing innovation. Engage with emergency communications activities that highlight amateur radio’s public service value.
The 430-440 MHz band remains primarily protected for amateur use, but this victory required sustained technical and legal advocacy. Our spectrum allocations, just like our open source projects, exist because communities actively defend and develop them. The technical part of a project is never the hardest part. The hardest part of any project is the people part. Negotiating, collaborating, compromising, defending, and communicating in a complex world are all “people work”.
Technical Details and References
For those interested in the regulatory details, please refer to the following documents.
FCC Proceeding 25-201 (application/licensing proceeding)
ICFS File Number SAT-MOD-20250612-00145 (FCC’s “case number” or filing reference for AST SpaceMobile’s request to modify their satellite authorization.)
Open Research Institute Comment to 25-201 (Filed July 21, 2025 by Michelle Thompson W5NYV)
FCC Decision (DA-24-756A1.pdf from August 29, 2025)
The full technical analysis includes frequency coordination studies, interference modeling, and alternative band analysis available through the FCC’s Electronic Comment Filing System.