AST SpaceMobile is a publicly traded satellite designer and manufacturer based in Midland, Texas, United States. The company is building the SpaceMobile satellite constellation, a space-based cellular broadband network that will allow existing, unmodified smartphones to connect to satellites in areas with coverage gaps. At the heart of AST SpaceMobile's value proposition is the fact that users will be able to connect to the company's satellites directly with their smartphones, without the need for specialized devices or satellite antennas. This is made possible by the satellites effectively acting as cell towers in space, using cellular spectrum and protocols, as opposed to traditional satellite spectrum and protocols. The earlier company description cited agreements and understandings with over 40 mobile network operators. Partner counts are dated business figures; they do not establish commercial availability in every partner market. The service will be available to the company's mobile network operator customers, which collectively represent a significant number of subscribers. The technology targets coverage gaps. Connectivity inside vehicles or buildings depends on penetration loss, visibility, antenna orientation and available link margin; indoor service is not a universal guarantee. The company's BlueWalker 3 prototype demonstrated a large deployable array in low Earth orbit. Later BlueBird spacecraft use larger arrays, so the prototype's former size record is historical. The satellite maintains low Earth orbit at an altitude between approximately 508 and 527 km (316 and 327 miles).

• Orbit and Constellation
  • Authorized orbital groups
• Spectrum and Bandwidth
  • U.S. direct-to-cell Spectrum / RF details
  • Outside-U.S. service spectrum
  • Feeder links and TT&C
• Roadmap and Constellation
• Demonstrated Capability
• Direct-to-Cell Architecture and Practical Constraints
  • Phone, satellite, gateway and mobile operator
  • Coverage, capacity and handset compatibility
• BlueWalker and BlueBird Evolution
  • BlueWalker 3 and BlueBird Block 1
  • Next-generation BlueBird and Block 3 roadmap
• Spectrum and Altitude Comparisons
  • Color-coded spectrum bands
  • Orbital altitude by authorized group
• FCC
  • Key records and authorization scope
  • Interference and operating conditions
• YouTube
• Reference

The photograph shows BlueWalker 3’s large tiled antenna array during ground work. The array places much of the antenna capability on the satellite, compensating for the small antenna and limited transmit power of an ordinary handset.

Orbit and Constellation

The early plan described 243 satellites. The April 2026 FCC order instead authorizes a 248-satellite configuration, subject to its conditions; an authorized total is not a count already in service. The company's satellites effectively act as cell towers in space, using cellular spectrum and protocols, as opposed to traditional satellite spectrum and protocols. The first five commercial BlueBird satellites, known as Block 1, launched on 12 September 2024. Indoor coverage remains dependent on propagation conditions and service availability, rather than being guaranteed by the constellation design

The historical illustration below labels AST at 725–740 km with 243 satellites. Those are earlier planning values. The April 2026 authorization lists several lower orbital configurations, including a 460 km case and nominal apogees near 520, 685 and 690 km. DA 26-391, pages 2–3.

An orbital plane is the geometric plane containing an orbit around Earth. Multiple satellites can follow approximately the same orbital path, separated along it. Different planes can have the same altitude but different orientations. Inclination describes the tilt relative to the equator; it is not a second altitude.

Authorized orbital groups

The following groups total 248 satellites in the April 2026 grant. The perigee and apogee are nominal values. The grant specifies altitude tolerances of plus or minus 30 km and inclination tolerances of two degrees.

• Deployment altitude, permitted operating range and current tracked altitude are different quantities.

Spectrum and Bandwidth

The handset link and the gateway link use very different frequencies. The handset uses cellular spectrum under the relevant operator and regulatory arrangements. High-frequency feeder links connect the satellite to ground infrastructure.

• AST SpaceMobile has achieved space-based LTE speeds of more than 10 Mbps using leased AT&T spectrum and Nokia Radio Access Network gear for testing.
• The September 2023 announcement reported a 5G call and a separate download test of approximately 14 Mbps; these should not be treated as one measured 5G session.
• The five Block 1 satellites launched in September 2024. The April 2026 FCC authorization covers a total configuration of 248 satellites, including further deployment.
• The company's satellites effectively act as cell towers in space, using cellular spectrum and protocols, as opposed to traditional satellite spectrum and protocols.
• Indoor and in-vehicle connectivity depends on the actual link budget and obstruction; a successful outdoor test does not guarantee service in every building.

U.S. direct-to-cell Spectrum / RF details

The order lists these U.S. Supplemental Coverage from Space ranges separately from overseas operations. The uplink is Earth-to-space, so its transmitter is the phone. The downlink is space-to-Earth, transmitted by the satellite.

The listed ranges are authorization envelopes. The usable carrier and bandwidth depend on the underlying spectrum rights, geography and deployment. They do not imply that one phone transmits across the entire range. DA 26-391, page 4 and grant conditions 1–4.

Outside-U.S. service spectrum

The same FCC order lists a broader set of direct-to-cell frequencies for operations outside the United States. Those entries remain subject to national permissions, certification requirements and interference conditions; they are not worldwide landing rights.

Do not pair these broad envelopes into a single invented FDD band. They cover different regional arrangements. The order specifically explains that its listing alone does not approve direct-to-cell operation outside the U.S. in 902–928 MHz. DA 26-391, page 4, footnote 14 and condition 1.

Feeder links and TT&C

Gateway links carry traffic between space and the terrestrial network, while TT&C controls the spacecraft. Their frequencies must not be confused with handset bands. Emergency channels also have narrower purposes than normal broadband operation.

The feeder allocations contain gaps, especially 50.2–50.4 GHz. They are not one continuous 37.5–51.4 GHz band. Exact waveform bandwidths and centre-frequency options remain in the grant. DA 26-391, pages 5–6.

• A smartphone communicates in the cellular band; it does not need a V-band feeder-link radio.

Roadmap and Constellation

The table below is retained as a historical 2025 presentation roadmap. Its block names, capacity ratios and broad tuning ranges are design descriptions. The later FCC grant provides a different, dated authorization baseline.

Source : 6G@UT Forum 2025: AST SpaceMobile System and Supplemental Coverage from Space for D2C

The FCC’s April 2026 configuration totals 248 spacecraft including the first five. Therefore, the roadmap’s shared Block 2 / Block 3 cell must not be added to the Block 1 count to derive a licensed fleet of 253. The roadmap also rounds orbital heights, while the FCC separately specifies perigee, apogee, tolerances and operational ranges.

The 700–960 MHz and 1.4–2.4 GHz rows describe broad roadmap ranges. They are not continuous operating allocations. In particular, the 2026 order reviewed here does not establish a Block 3 subscriber authorization across 1.4–2.4 GHz. This part of the presentation remains a development roadmap, not a verified deployed capability.

Capacity ratios need a defined reference and traffic model. A 100-times comparison does not mean that every handset becomes 100 times faster. Array size, processing bandwidth, spectrum reuse and simultaneous user loading affect different parts of network capacity.

• Use the roadmap to understand design evolution, and the dated authorization to identify permitted operations.

Demonstrated Capability

Demonstrations establish that a connection worked under the reported test conditions. They do not establish continuous coverage, a guaranteed rate or commercial availability everywhere. The dates below preserve the difference between early tests and operational service.

The September 2023 announcement identifies a 5G call on 8 September using a Samsung Galaxy S22 and AT&T spectrum. It reports approximately 14 Mbps in a separate download test. The public announcement does not justify labelling that throughput as the result of the same 5G call. AST September 2023 announcement.

For comparison, a peak-rate design target describes what a system is intended to support. A measured download rate describes one test. Commercial user throughput additionally depends on scheduling, spectrum, signal quality and other users sharing the beam. The historical table should therefore be read as evidence of milestones, not a service-level agreement.

• Keep demonstrated throughput, per-cell design peaks and guaranteed user service separate.

Direct-to-Cell Architecture and Practical Constraints

The handset has a small antenna and limited transmit power. AST places a large phased array on the spacecraft to receive that weak signal. Ground infrastructure then connects the satellite path to the mobile operator.

Phone, satellite, gateway and mobile operator

The signal follows two different radio links before it reaches the operator network. The user link uses cellular spectrum. The feeder link serves a ground gateway, where the connection enters the terrestrial infrastructure.

AST’s architecture description assigns compensation for delay and Doppler to its gateway technology. Satellite motion changes propagation delay and frequency offset continuously. Supporting an ordinary handset therefore requires network-side handling of those effects. The public description is high level; it does not expose the complete PHY timing or scheduler implementation. AST: How it works.

Coverage, capacity and handset compatibility

A satellite footprint describes where a beam could reach under suitable geometry. Service also requires a compatible band, operator integration, authorization and sufficient signal margin. These conditions explain why a large footprint is not a continuous-service guarantee.

A building or vehicle adds penetration loss. Trees, terrain and body blockage can reduce the margin further. Increasing satellite array gain helps the link budget, but does not remove these losses. The network also shares resources among users within each coverage cell, so coverage area and per-user throughput are different measures.

Direct-to-cell describes the endpoint relationship. It does not by itself establish that a phone implements every Release 17 or later 3GPP NTN feature. AST targets existing cellular handsets; a specific protocol capability must be supported by device and network evidence. The 2026 order separately addresses device-certification waivers and partner spectrum arrangements.

• Large satellite antennas support the weak handset link; gateway processing and operator integration remain essential.

BlueWalker and BlueBird Evolution

BlueWalker 3, BlueBird Block 1 and the larger next-generation BlueBirds represent different development stages. The progression combines flight demonstration, initial commercial spacecraft and increased antenna and processing capability. It should not be reduced to satellite count alone.

BlueWalker 3 and BlueBird Block 1

BlueWalker 3 provided an in-orbit test platform for direct connections with ordinary phones. The first five commercial BlueBirds followed in September 2024. A successful launch established deployment progress, while service continuity still depended on further constellation growth.

The Block 1 launch announcement described planned non-continuous service. That qualification matters: a small initial fleet cannot be assumed to give uninterrupted visibility everywhere. The 693-square-foot array class appears in both the retained roadmap and AST’s architecture description. AT&T, 12 September 2024.

Next-generation BlueBird and Block 3 roadmap

AST describes next-generation BlueBirds with arrays of approximately 2,400 square feet and an AST5000 processing platform. The company presents these as capability improvements, while the reviewed FCC order defines the licensed constellation and frequency scope.

The next-generation product page lists BlueBird 6 as launched in December 2025 and subsequent launches in 2026. It advertises 10 GHz of processing bandwidth and peak rates above 150 Mbps per coverage cell. These are company design-capability figures, not 10 GHz of licensed handset spectrum or a guaranteed rate for each user. AST next-generation BlueBird overview.

The historical Block 3 column is retained with its source. The reviewed sources do not establish a separately deployed Block 3 fleet or a complete Block 3 RF authorization. Where the FCC groups spacecraft by orbit, this note uses those groups rather than assigning every group to a marketing block without evidence.

• Processing bandwidth, licensed RF bandwidth and delivered throughput describe different quantities.

Spectrum and Altitude Comparisons

The comparison separates hardware evolution from regulatory frequency rights. The historical roadmap describes spacecraft blocks; the April 2026 grant specifies bands and orbital groups. A spacecraft block does not automatically acquire every frequency in its tuning range.

Color-coded spectrum bands

The handset plot uses separate colors for the three U.S. SCS groups. The feeder plot uses separate colors for link direction and the outside-U.S. band. This avoids presenting the same authorization as three different generation-specific grants.

Figure 1. Colors identify service groups, not satellite generations. All ranges remain subject to the grant and applicable spectrum arrangements. Source: DA 26-391, page 4.

Figure 2. The 50.2–50.4 GHz gap is preserved. The purple band is restricted to outside-U.S. operations. These are gateway frequencies, not phone frequencies.

Each endpoint is a band boundary. The charts do not depict the bandwidth of a particular transmission. TT&C and outside-U.S. subscriber bands remain in the detailed tables because their purpose and conditions differ.

Orbital altitude by authorized group

The altitude plot shows nominal perigee-to-apogee intervals from the grant. It groups the five and twenty-two spacecraft entries where their nominal intervals coincide. It does not show a live satellite tracking inventory.

Figure 3. Nominal perigee / apogee from DA 26-391, pages 2–3. Counts total 248 authorized satellites. Altitude tolerances, lower operating permissions and deployment altitudes are excluded from these bars; see the orbit table.

A line at 460 km represents the circular nominal case. Short bars near 520 and 690 km represent slightly different perigee and apogee values, not multiple generation heights. The plus or minus 30 km tolerances and permitted lower operating altitudes are documented in the orbit table rather than included in these nominal bars.

• Read each plot with its date and scope; nominal authorization values are not current measured positions.

FCC

The 2026 FCC order changes the regulatory baseline from early deployment permissions to a larger constellation with SCS authority. The earlier public notice records the request stage; the later order records a conditional grant.

[1] AST&Science; LLC  

Key records and authorization scope

These two records are useful together because they distinguish a filed request from the resulting authorization. The 2026 order includes its own orbit and frequency schedule as well as conditions on geography, devices and interference.

The 2026 grant authorizes 223 additional satellites beyond the 25 previously authorized. This is a licensing progression, not a statement that 248 satellites were already launched. The order also separates U.S. SCS from direct-to-cell operations outside the U.S., which remain subject to additional national and certification requirements.

Interference and operating conditions

The grant permits service subject to conditions that matter to the technical design. Beam coverage must respect spectrum rights and geographic boundaries, while interference protection remains necessary even when the phone itself requires no special satellite antenna.

For the specified CONUS waiver, aggregate field strength outside leased areas must not exceed 40 dBµV/m unless the affected licensee agrees otherwise. The order requires notification near neighboring co-channel license boundaries and resolution of interference. It also prohibits the specified 800 MHz service to airborne devices. These are examples from the grant, not an exhaustive operating checklist.

The source review covered the frequency and orbit schedule and the initial grant conditions, together with selected operator announcements. The remaining conditions and legal analysis were not reviewed exhaustively. A specific service deployment must use the complete applicable authorization rather than this explanatory summary.

• FCC authority, actual deployment and commercial availability are separate milestones.

YouTube

• [RNN]"SpaceMobile" Explored - Interview with AST & Science CEO Abel Avellan (Jun 2020)
• NASA warns 5G SpaceMobile could cause catastrophic collision (Nov 2020)
• Nasa: Huge 5G Satellite Constellation Could be Catastrophic| Galactic Energy Succeeds Orbital Launch (Nov 2020)
• AST SpaceMobile Overview (Dec 2020)
• AST SPACEMOBILE INVESTORS:Part1 The Product #Merger  #AST  # NPA (Dec 2020)
• AST SPACEMOBILE INVESTORS: Part Two, the Satellites #Merger #AST #NPA (Dec 2020)
• Satellite to smartphone broadband company AST & Science to go public (Dec 2020)
• AST SpaceMobile / NPA - Is this a better solution than Space X? (Jan 2021)
• Jason Silva, friend of the #SpaceMobile​ mission (Mar 2021)
• BlueWalker 3 Satellite's Assembly, Launch, and Deployment - AST SpaceMobile (Nov 2022)
• First-Ever 5G Connectivity from Space to Everyday Smartphones Achieved by AST SpaceMobile- AST SpaceMobile (Sep 2023)
• The First Commercial Ever Streamed to a Cell Phone from Space - AST SpaceMobile (Apr 2024)
• How AST SpaceMobile's BlueBird 1-5 Mission Will Work - AST SpaceMobile (Sep 2024)
• AST SpaceMobile's Pioneering Year for Space-Based Cellular Broadband - AST SpaceMobile (Dec 2024)
• #mwc25 - Fireside Chat at the Rakuten Booth with Abel Avellan and Mickey Mikitani, CEO of Rakuten. - AST SpaceMobile (Mar 2025)
• AST SpaceMobile at MWC Barcelona 2025 - V-Talk at the Vodafone Booth with Scott Wisniewski - AST SpaceMobile (Mar 2025)
• 6G@UT Forum 2025: AST SpaceMobile System and Supplemental Coverage from Space for D2C - Lindmark Melo (Apr 2025)

Reference

• NASA objects to new mega-constellation, citing risk of “catastrophic collision” (Nov 2020)
• Planned satellite constellation poses a collision threat, NASA says: reports(Nov 2020)
• AST SpaceMobile CEO outlines capabilities of direct-to-smartphone LEO satellite service - Urgent Communications (Apr 2021)
• AST SpaceMobile Provides Second Quarter 2023 Business Update - AST/SpaceMobile
• AST (SpaceMobile)-NewSpace Index
• AST SpaceMobile adjusts launch plan for potential direct-to-device customer - SpaceNews (Nov 2023)
• AST SpaceMobile Achieves Space-Based 5G Cellular Broadband Connectivity From Everyday Smartphones, Another Historic World First - AST (Sep 2023)
• AST SpaceMobile Announces Successful Orbital Launch of Its First Five Commercial Satellites - AT&T (Sep 2024)
• BlueWalker 3
• Space 5G Cellular Broadband
• Vodafone achieves first space video call using regular smartphones - TELECOMS (Jan 2025)
• DA 26-391: AST Authorization and Order, 21 April 2026 (selected grant pages)
• DA 25-815: AST SCS applications accepted for filing, 5 September 2025
• AST SpaceMobile: How it works
• AST SpaceMobile: Next-generation BlueBird overview