On The Record: AST's Constellation Modification Application for SCS, SB 25-201
Comments due July 21, but T-Mobile has already weighed in...
FCC Space Bureau Partially Accepts AST’s NGSO Constellation Modification, Seeks Comment on TT&C Aspects
The Federal Communications Commission’s (FCC) Space Bureau initiated a proceeding to review a significant modification application from AST & Science, LLC (AST). By accepting only a portion of AST's request for public comment, the Bureau narrowly defined the initial scope of review for the company's proposed 248-satellite non-geostationary orbit (NGSO) constellation. This action establishes the framework for stakeholder comments, focusing them solely on the telemetry, tracking, and telecommand (TT&C) operations of the proposed constellation, while deferring consideration of the broader service proposals.
The proceeding stems from a June 12, 2025, modification application in which AST sought to expand its existing five-satellite authorization (Call Sign S3065) to a full 248-satellite NGSO system.1 The primary purpose of the modification was to enable the provision of supplemental coverage from space (SCS) to unmodified mobile devices in the United States using 700 MHz and 800 MHz spectrum held by its terrestrial partners, AT&T and Verizon Communications, Inc. (Verizon), under a secondary mobile-satellite service (MSS) allocation.
AST’s application proposed deploying 23 satellites at an altitude of 520 km, 192 satellites at an altitude of 690 km, both with an inclination of 53 degrees, and 28 satellites at an altitude of 685 km with a 98.1318 degree inclination. AST noted that lowering the operational altitudes was consistent with prior FCC guidance. For feeder link and TT&C operations, AST requested that the 45.5-47 GHz band be added to its existing authorizations, clarifying in a subsequent letter that this band would only be used for uplinks from non-U.S. earth stations. The application also sought authority for MSS operations in a range of bands from 617 MHz to 960 MHz.
A key element of AST’s request was a waiver of the Geographically Independent Area (GIA) entry criteria under 47 C.F.R. § 25.125(a). This rule requires an SCS applicant to have lease agreements with terrestrial licensee(s) that, whether singly or collectively, hold all co-channel licenses throughout the relevant GIA. AST argued that its leases with AT&T and Verizon cover a "significant percentage" of the contiguous United States (CONUS) GIA. The company asserted that its advanced beam-forming and beam-contouring technology would enable comprehensive protection of co-channel terrestrial incumbent operators, fulfilling the rule's purpose of preventing harmful interference and making a strict application of the rule unnecessary.
On June 20, 2025, the Space Bureau released a Public Notice in SB Docket No. 25-201 accepting for filing, in part, AST's modification application.2 The Bureau accepted the application for filing only for the requested TT&C operations in the 430-440 MHz, 2025-2110 MHz, 2200-2290 MHz, and the new 45.5-47 GHz bands. The Bureau stated it did not accept for filing AST's requests for operations other than TT&C, including the SCS and GIA waiver requests, at this time.
The proceeding was designated as "permit-but-disclose" for ex parte purposes. The Space Bureau established Comment and Reply deadlines of July 21, 2025, and August 5, 2025, respectively.
On June 26, T-Mobile filed a letter requesting that the Space Bureau refrain from accepting the SCS portion of AST's application unless AST provides additional public information.3 T-Mobile argued that holding the application in abeyance is necessary to ensure interested parties have a meaningful opportunity to assess the proposal for harmful interference. Specifically, T-Mobile demanded that AST make public its "Annex B – SCS 700/800 MHz Interference Analysis," for which AST had requested confidential treatment. T-Mobile asserted that withholding this analysis is contrary to the SCS framework, which requires technical details to be available for public assessment. It noted that the Bureau had required T-Mobile's partner, Space Exploration Holdings, Inc. (SpaceX), to provide substantial, publicly available technical information for its SCS application.
Further, T-Mobile argued that AST must provide more specific information about its spectrum usage and geographic coverage, including detailed coverage maps for each leased spectrum block. T-Mobile contended this information is critical because AST is seeking a waiver of the GIA rule and does not hold nationwide rights to the proposed spectrum, unlike the T-Mobile/SpaceX partnership. Without detailed maps, T-Mobile and other licensees cannot evaluate the risk of in-band interference in areas where AT&T and Verizon do not hold licenses.
The Comment deadline is July 21st. We will provide updates as this Docket matures.
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[Application, AST & Science, LLC, https://www.fcc.gov/ecfs/document/106201991509823/1]
[Public Notice, Space Bureau, https://docs.fcc.gov/public/attachments/DA-25-532A1.pdf]
[Letter, T-Mobile USA, Inc., https://www.fcc.gov/ecfs/document/106262778126093/1]