Before the

FEDERAL COMMUNICATIONS COMMISSION

Washington, D.C. 20554

)
In the Matter of: ) ICFS File No:
) SAT-MOD-20250612-00145
AST & Science, LLC ) ECFS File:
) SB Docket No. 25-201
Application for Modification of License )
to Launch and Operate the SpaceMobile )
Non-Geostationary Orbit Satellite System )
) Call Sign S3065

PETION TO DENY (in part)

Mario Lorenz
Amateur Station DL5MLO
Schöffenhausweg 1
98693 Ilmenau
GERMANY

With Public Notice DA 25-532, as published June 20, 2025, the Space Bureau accepted

for filing AST & Science LLC’s (“AST“) above-mentioned application to modify its existing

license to authorize an additional 243 satellites in their constellation, in particular for

Telemetry, Tracking & Command (TT&C) operation in the 430-440 MHz and other bands.

The Application itself was published June 25, 2025. The FCC is seeking comments and

petitions by interested parties.

For the reasons set forth below, I respectfully petition the FCC to deny this application

with regard to the use of the 430-440 MHz band. I take no position on the operation of the

constellation itself or on use of other radio spectrum proposed to be used by AST.

I act only in my own private capacity, and do not purport to represent any other Amateur

Radio operators or organizations, although I am certain other Amateur Radio operators would

share at least part of my concerns.

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 I. Introduction
AST has, using its experimental Bluewalker-3 (“BW-3”) and its first set of 5 commercial

Bluebird 1-5 (“BB1-5”, “Block-1”) spacecraft, demonstrated the initial stages of its space-

borne direct-to-device (“D2D”) Broadband Service.

For Telemetry, Tracking & Command (TT&C) use, it requests authorization to use the

430-440 MHz band (“70cm band”), outside the United States. Previously, the FCC has

granted such authorization1 for the first batch of 5 Bluebird satellites, on a no-interference/no

protection basis.

AST is now seeking to launch an additional 243 satellites to complete its constellation, and

in its application is seeking to extend the TT&C license to accordingly. Actually, AST is

vague about what exactly it seeks. As will be discussed below, in the best case, ASTs

application could be construed in a way that AST does not seek any 70cm operation of its new

spacecraft at all. In this case, the FCC simply should not make such a grant, and this petition

would be moot. However, this limitation to 5 satellites is not explicitly stated in the pending

application and supporting material anymore. In the worst case therefore, AST seeks

worldwide access to a significant portion of this spectrum in a way which would almost

guarantee significant international harmful interference. This would be an unprecedented grab

of spectrum, and in violation of applicable Radio Regulations.

At issue is AST’s proposed use of the 70cm band outside the United States, in particular

over Europe (ITU Region 1) where it is allocated to Amateur Radio on a (co-) primary basis.

Unlike Amateur Radio stations in the US, who have a much larger 70cm allocation (420 MHz

… 450 MHz) and other bands (220 MHz) not available to Amateur Radio stations in Region

1, amateur radio activity is much more concentrated. The 70cm band is heavily used. It is one

of the few bands available to Novice class operators in Germany. It is therefore a critical and

much used resource for the amateur radio community, including for personal experimentation,

1 39 FCC Rcd 8558 (10) / DA-24-756

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self-education, operator training, competitions, emergency preparedness and all other benefits

that make out Amateur Radio.

II. Standing
I am a German citizen, residing in Germany. I am a duly licensed Amateur Radio operator

with callsign DL5MLO2. I regularly operate on various Amateur Radio bands, including the

frequency band in question, with a focus on amateur radio satellites. I take part in amateur

radio competitions (“contests”), study propagation phenomena and generally am interested in

weak-signal modes, requiring cutting edge technologies to allow making radio contact. I

further will be the responsible operator of an Amateur Radio Satellite3 which has successfully

completed IARU coordination, BNetzA licensing and ITU filing using Earth-to-Space

frequencies in the 70cm band. This satellite is currently being integrated and planned to

launch later this year.

In the Amateur Radio service, unusual modes of propagation, like moon bouncing (EME),

atmospheric ducting and satellite operations are frequently employed. Modes of operation not

seen in any other radio service, like radio competitions (“contests”), are popular. Often, these

require reception of very weak signals, with success hinging on a particular clean band

without interference. Under these conditions, even slight interference does rise to the level of

harmful interference as defined in 47 CFR 2.1 by repeatedly interrupting my radio contacts,

falsifying the results of my studies and possibly interfere in the control of the amateur radio

spacecraft mentioned above, all of which causes me harm. I therefore have a strong interest in

the protection of the spectrum which I legally use and would be negatively affected by the

interference caused if the FCC were to grant AST’s application. With the Amateur Radio

2 In the past, I have also held an FCC issued Amateur Radio license with callsign
KC5WHE, which I let lapse due to changed CEPT licensing policies
3 PRECURSOR, Callsign DP0PRE

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Service a primary service in ITU Region 1, I need not brook interference from AST’s

transmissions.

III. Granting ASTs application would be in violation of Article 4.2 ITU Radio
Regulations (RR)
In its previous applications4, AST acknowledged (and the FCC later found5) that its

proposed operation of TT&C in the 70cm band is contrary to the international Table of

Frequency Allocations (“the Table”). Article 4.2 ITU Radio Regulations (“RR”) requires that

frequency assignments to stations capable6 of causing harmful interference to the services

rendered by the stations of another country must be made in accordance with the Table of

Frequency Allocations. The 70cm Space-To-Earth transmission of AST’s constellation is such

a case. Specifically and explicitly applying for operation outside the United States, ASTs

footprint per spacecraft7 is spanning a substantial part of Europe and thus significantly

exceeds the geographical borders of either FCC’s or the target ground stations’

administrations geographical jurisdiction (Bulgaria)8. Yet, as a U.S. spacecraft, ensuring RR

compliance of the spacecrafts emissions is the task of the FCC, in particular if the FCC

(co-)authorizes such emissions. Since the potential of interference clearly is international, RR

§4.2 applies.

To grant this application, the FCC would have to find that AST’s proposed use is incapable

of (and not merely operated in a way not to) causing harmful interference to any other

4 SAT-PDR-20200413-00
5 AST&Science LLC, Order & Authorization, DA-24-756 (SB2024), Para 14
6 Note that this is a different standard than the „operated in such a manner as to not cause
harmful interference“ in RR §0.4 / ITU Constitution 197. Here, the mere capability
matters.
7 See AST supplemental filing PC0105678 USASAT-NGSO-20_V12[1].pdf describing the
UHF downlink as omnidirectional and service area „visible earth“.
8 When AST refers to the „applicable laws and regulations“to such operation in any foreign
jurisdiction“, I assume it refers only to the target jurisdictions for its ground stations, and
not all other countries world wide that are affected by its “visible earth” TT&C beam

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international radio service (including, but not limited to the Amateur Radio services). Such a

finding is not supported by the record.

The RR §4.4 notice of no-interference/no-protection alone is not sufficient. It is merely an

additional safeguard the RR’s require of an administration when they grant deviations from

the rules if, and only if, they they may do so. For example, if this current application were for

TT&C solely over continental US territory, and any potential interference might only be

(U.S.-) national, §4.2 would not apply, and a §4.4 notice might suffice.

IV. AST’s Interference Analysis is insufficient

In fact, AST does not even attempt to address the issue of interference to the Amateur

Radio service (and the Amateur Radio Satellite Service), with all its filings in support of the

current application relating to the feeder and SCS authorization requests (which the

commission has not even accepted for filing yet). The only relevant pleading is in the

previous application9 where AST acknowledged the Amateur Radio allocations, but again

neglected to discuss the interference potential, addressing only the Radiolocation service

(another primary user of this band).

Without a clear showing that AST does not cause harmful interference under §4.4, let alone

the incapability to cause interference under §4.2, the application should be denied.

V. AST conceded the 430-440 MHz would not be used

The previous authorization to use the 430-440 MHz band was made on the representation

by AST that only the first batch (Block-1) would use the 430-440 MHz TT&C. Later satellites

were to use the S-band exclusively. See SAT-AMD-20240311-00053, PC0097863 Supplement

(“Interference Analysis”), section 2, “Planned Usage”.

9 SAT-AMD-20240311-00053 PC0097863 Supplement, section 2.

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 A significantly increased number of satellites will surely change all the underlying

assumptions. With a planned total of 248 satellites in orbit, almost certainly there would

always be one or more satellites in view, causing significantly more interference potential and

therefore the likelihood of harmful interference over time than only the 6 existing satellites.

AST does not address this significant additional interference. ASTs silence either means that

– as filed in its (old) interference analysis – its future 243 satellites only use S-Band spectrum

for TT&C, or that it failed to show that there would be no capability to cause harmful

interference. Either way, the FCC should deny additional 430-440 MHz usage.

Additionally, if AST considers the current request a proper incremental “adjustment” of the

number of 70cm transmitters, this would constitute gamesmanship to boil the frog slowly by

incrementally applying for spectrum (including via experimental licenses) and building an

argument to gain access to large swaths of valuable spectrum to the detriment of existing

users. This is would be contrary to 47 CFR §2.102(b)(a) and certainly not in the public

interest. The FCC should put a stop to this now.

VI. AST’s 70cm License Request is unduly broad

Together with its Application Form, AST submitted a narrative with several Annexes, and a

Technical Statement, explaining the proposed changes. Unfortunately, no detailed information

of the 430 MHz for its additional 243 satellites can be found to justify assignment of a whole

10 MHz of spectrum. No statement was made if any of the satellites would share the same

carrier frequencies for TT&C or if they will use their own individual carrier frequencies.

Again, this lack of information could either mean that AST does not want to use the 70cm

band anymore, or that – with this information not (yet) available - no proper interference

analysis has been made, both grounds for denial of this application.

If AST had done its interference analysis properly, it would know that the usage of the

70cm spectrum by the Amateur Radio service is diverse and different uses have different

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protection requirements. While not mandatory, many amateur radio operators in Region 1

adhere to the Internation Amateur Radio Union (IARU) Region 1 bandplan10. As can be seen

there, certain frequency ranges are used for communication modes that are especially

vulnerable to interference. In particular the ranges 432.000 – 432.500 MHz are suggested to

be used for weak signal modes and the range 435.0...438.0 MHz is used for Amateur Satellite

Service, requiring and deserving particular protection. On the other hand, at least in some

administrations, the frequency band 433.05-434.79 MHz is designated for ISM applications11.

A certain level of interference is expected there, so arguably, AST using these frequencies

would have less impact there.

The remaining frequency ranges of the 70cm band are also in use, and harmful interference

can not be ruled out. If AST’s application could be trimmed down to a reasonable range or set

of possible frequencies while there is still time to comment, a specific interference assessment

would be greatly simplified.

VII. AST’s application is unduly vague

AST has, in its various filings, used several terms to refer to its 430-440 MHz TT&C

traffic. AST has referred to them in their various filings as generic TT&C, as “off-nominal

TT&C”, or “emergency TT&C” communications facilities. These terms need a clear

definition. Knowing how long and/or how often AST proposes to use these communication

facilities would be an important factor in assessing interference potential. Certainly, AST does

not want to imply that distress traffic is involved here, which would give it priority access 12 to

the radio waves instead of the non-interference/no-protection status it purports to seek. The

term “LEOP” (“Launch & Early Orbit Operation”) also has no specific time limit and no duty

10 https://www.iaru-r1.org/wp-content/uploads/2021/03/VHF_Handbook_V9.01.pdf, Chapter
1.5
11 See ITU Radio Regulations, Art. 5.280
12 ITU RR §0.7, ITU Const Article 200

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cycle limitation. AST’s application is therefore a well-hidden request for authorization of

permanent transmission during the lifetime of the constellation.

Rumours13 have it that for Bluebird and Bluewalker, AST has used used this “emergency”

communication for prolonged periods of time, corrobating above assumption. The SATNOGS

network reports reception of various BW3 and BB reception over Europe just these days14.

This is either a an incredibly liberal interpretation of “LEOP”, or the spacecraft are in an

ongoing and continuing emergencies, casting doubt in AST’s ability to safely operate a 248

spacecraft constellation.

With AST not having made a detailed and specific analysis, despite its by now significant

on-orbit experience enabling it to do so, detailed and specific comments on this application

are not possible. AST must clarify what kind of spectrum usage it seeks, at the very minimum

the frequencies, bandwidths, operation time, operating circumstances etc. However, once that

is done, it will become obvious that ASTs extensive usage of the spectrum will be a

significant source of interference towards the primary incumbent users operating on this

frequency conformant to the ITU frequency table, precluding a grant of AST’s application

under either RR §4.2 or §4.4.

VIII. Interference already present

Further based on the SATNOGS observations (see above), third party reports, including

comments made in this proceeding15 and an oral conversation I had with with an BNetzA

representative, it appears that AST is aware of specific harmful interference caused by its

existing spacecraft in orbit, leading even to a shutdown order over Germany by BNetzA. If

true, this would be a material fact, and it is astonishing that it is not discussed in AST’s

13 While I find them credible, this is based on third-party reports; I have no first-hand
knowledge of this aspect
14 See e.g. https://network.satnogs.org/observations/11953687/, retrieved 07/13/2025
15 See e.g. SB 25-201, Submission 10711020273665

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application or interference reports. The Commission should require AST to amend its

interference analysis with this relevant information and interference reports it received for

BW3/BB1-5 operations (if any). Unless clearly refuted, they would be evidence that AST is

unable to honor its §4.4 non-interference pledge, and the FCC should deny the application on

this basis.

IX. Petition not in the public interest

47 CFR 309(a) requires the Commission to determine whether a grant of the Application

would be in the public interest. AST brings various reasons why this would be the case.

While these reasons may have merit, the FCC must weigh them against other public interests.

One particular such interest would be to abide by the international treaties that the USA are a

member16. Granting the application, in violation of RR §4.2 as described above, would then

also not be in the public interest.

If the FCC would grant the present application and harmful interference occured, a

cessation of emissions order undoubtedly would be sought. The FCC would then face the

dilemma of not granting this remedy – in further violation of the RR and its own rules – or

granting it, which would cause a loss of ASTs TT&C capabilities and as a result could result

in the loss of the spacecraft and/or further dangerous situations including RF interference on

other bands and/or possible collisions. Neither would be in the public interest. The FCC

should therefore deny the application now, and require AST to move this TT&C to an

appropriate frequency band consistent with the Frequency Table, where this issue does not

exist.

X. Possible remedies or conditions

The best solution would of course be that AST seeks authorization to use spectrum that

does conform to the international Table of Frequency allocations. This would also afford AST
16 See also 47 CFR § 303 (r)

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the protection from interference provided by the RR’s, which may be useful while recovering

from an “emergency”.

The FCC could limit AST’s use of the 430-440 MHz band to the Earth-to-Space direction

only. Since those uplink transmissions can be made with the minimum required uplink

transmission power, using directive antennas, there would be no widespread interference as is

to be expected in the downlink. In fact, the uplink interference could possibly controlled such

that interference would be limited to the jurisdiction of the authorizing administration, hence

RR §4.2 would not be implicated. Interference with Spacecraft in the Amateur Satellite

service could (and hopefully would) be avoided on a case-by-case basis.

The FCC could limit AST’s Space-to-Earth usage to the ISM Frequency range 433.05-

434.79 MHz. While no full remedy, this would at least limit the harm to frequencies where in

many jurisdictions (including where I live) interference can be expected.

At the very least, the FCC should require from AST a clear showing and commitment to

protect the Amateur Radio and Amateur Radio Satellite services. Such commitment would

include requiring AST to amending its interference study, giving due considerations to the

Amateur Radio and Amateur Radio Satellite services. Specifically, it would avoid the use of

frequency ranges that need special protection (see VI above).

For all the foregoing reasons, I respectfully request that the FCC deny AST’s Application
to operate an additional set of 243 satellites conducting TT&C operation in the 430-440 MHz
band.

/s/ Mario Lorenz

Ilmenau, 15 Jul 2025 , Mario Lorenz, DL5MLO

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Affidavit

I, Mario Lorenz, hereby affirm that the above statements are true and correct to the best of my

knowledge and ability. Where based on third party reports, this is clearly stated.

/s/ Mario Lorenz

Ilmenau, 15 Jul 2025 Mario Lorenz

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Certificate of service

I, Mario Lorenz, certify on this 15 Jul 2025, that I have served copies of my Petition to Deny
via electronic mail to:

Jennifer A. Manner, Senior Vice President, Regulatory Affairs and International Strategies
Phuong Pham, Vice President, Regulatory Affairs
AST & Science, LLC
2901 Enterprise Lane, Midland TX, 78706
(applicant)

Timothy L. Bransford
Greenberg Taurig, LLP
2101 L Street N.W., Suite 1000
Washington, D.C. 20037
timothy.bransford@gtlaw.com
(Counsel to AST & Science, LLC)

/s/ Mario Lorenz

Ilmenau, 15 Jul 2025 Mario Lorenz

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