Full Breakdown
Anduril Unveils Steelfin: A Modular, Low-Cost Interceptor Family
By Drooid · · How we work
Core Unveiling and System Overview
On October 12, 2026, Anduril Industries announced the Steelfin family of surface-to-air interceptor missiles. The system uses a common two-stage architecture: a swappable solid-rocket booster and a shared terminal interceptor that retains the same airframe, avionics, software and flight-control suite across all variants. The modular approach lets operators match capability and cost to threats ranging from one-way attack drones to advanced ballistic, cruise and hypersonic weapons.
Background and Strategic Context
The launch follows a U.S. push to expand air- and missile-defense inventories after recent high-intensity conflicts exposed shortages of affordable interceptors. The Army’s Future Interceptor program seeks a Patriot-compatible missile to fill the range gap between the PAC-3 MSE and THAAD. Steelfin is positioned as a cost-effective alternative for that requirement.
Technical Design and Configurations
- Booster sizes: 10-inch, 18-inch and 21-inch diameters for range and altitude tailoring.
- Terminal stage: Shared interceptor module that can accept radar or infrared seekers and various payloads without redesign.
- Launch platforms: Compatible with land-based launchers (M903A2, PAC-3, CAML), the Mk 41 VLS, Typhon containers and emerging containerized launchers.
- Mission set: Configurable for point defense, lower-tier integrated air-defense, and upper-tier ballistic missile defense (not exo-atmospheric midcourse).
Production Plans and Cost Objectives
Anduril plans to produce “several thousand” Steelfin interceptors annually in the near term, with senior director Steve Milano later projecting “multiple thousands” to “hundreds of thousands” per year depending on demand. Full-rate production is expected by the end of 2028 or early 2029, with sub-assemblies built at the Arsenal-1 facility in Ohio and final integration performed with a limited set of partners.
Cost-target claims cite a unit price roughly one-third of a PAC-3 MSE interceptor (about $5.3 million) and a “more exquisite” variant between the PAC-3 MSE and THAAD ($15.5 million). The Army’s solicitation for a low-cost interceptor seeks a unit cost below $1 million, a figure Anduril has not directly matched but acknowledges as a market driver.
Official Statements & Responses
Anduril’s leadership highlighted the common architecture’s role in high-volume production and rapid reconfiguration for emerging threats. The company emphasized integration of commercial off-the-shelf components and sourcing rocket motors from multiple suppliers to reduce vendor reliance. Ballistic testing with representative air vehicles is complete, and flight testing of Steelfin variants is slated for 2027.
Conflicting Reports & Gaps
- Production volume: The short-term target of “several thousand” per year contrasts with Milano’s broader range, leaving scaling timelines unclear.
- Cost estimates: Anduril’s one-third PAC-3 price target still exceeds the Army’s sub-$1 million goal, indicating an unresolved cost gap.
- Program selection: Sources say Steelfin meets Future Interceptor requirements, but Anduril declined comment on formal selection status.
Verbatim Quotes
- “One-way attack drones, ballistic missiles, cruise missiles, hypersonic weapons… our military and our allies’ militaries are struggling with a set of legacy interceptors that are not scalable, and are not able to match the volume of the threat that they’re faci ng,” — Chris Brose, Anduril president and chief strategy officer
- “We’ve intentionally designed the Steelfin configuration with a modular mounting, so we can take in new providers as well as utilize our integrated and internal rocket motor systems,” — Steve Milano, senior director of missiles
- “It is an open system, so the ability to fly it with different rocket motors, different seekers, to be able to swap these components out, to be able to reconfigure the system for a range of different threats is a feature that we built into this,” — Christian Brose, Anduril president and chief strategy officer
What’s Next
- 2027: Flight testing for Steelfin variants.
- Late 2028 – Early 2029: Full-rate production at Ohio Arsenal-1.
- Future Army competitions: Ongoing participation in the Low-Cost Interceptor program and Future Interceptor solicitation, with selection outcomes pending.