Anduril has unveiled Steelfin, an interceptor designed to address a growing challenge for the US military and its allies: defending against large numbers of aerial threats with systems affordable enough to produce at scale. The company is aiming to price Steelfin at about one-third the cost of the Patriot system’s current PAC-3 Missile Segment Enhancement (MSE) interceptor.
Chris Brose, Anduril’s president and chief strategy officer, said attack drones, ballistic and cruise missiles, and hypersonic weapons are putting pressure on stocks of legacy interceptors. In his view, those systems cannot be produced quickly enough or in sufficient quantities to match the volume of threats.
Brose said Anduril has been developing Steelfin for several years, anticipating stronger demand for lower-cost interceptors.
A modular design built for multiple threats
Steelfin is designed to be modular, allowing it to use different rocket motors and seekers and to launch from a range of platforms. Those include PAC-3, CAML and Typhoon systems, as well as containerized munitions canisters.
The interceptor can be reconfigured for different targets, from low-cost drones such as Iranian-made Shaheds to ballistic and cruise missiles and hypersonic weapons.
Competing for US Army programs
Anduril is pursuing the US Army’s low-cost interceptor program with Steelfin. The company was among the vendors selected to advance to testing and demonstrations in the xTech Apex Intercept competition, which the Army held to identify effective, more affordable interceptors.
Steelfin could also be a candidate for the Army’s Future Interceptor program, an effort to develop a next-generation successor to the PAC-3 MSE. Anduril has not confirmed whether its interceptor was selected for the competition. Steve Milano, the company’s senior director of missiles, said, however, that Steelfin is a natural fit for the requirements.
According to Milano, the Army is seeking an interceptor with a 7–10-inch terminal section and a 10–13-inch booster, allowing it to fit existing Patriot launchers and the Common Autonomous Multi-Domain Launcher (CAML). He said Steelfin aligns well with those dimensions.
Full-rate production targeted for 2028–2029
Anduril expects to reach full-rate production of Steelfin in late 2028 or early 2029. Depending on demand from the United States and international customers, the company is considering annual output ranging from several thousand units to nearly hundreds of thousands.
Most subassemblies are expected to be manufactured at the company’s Arsenal-1 facility in Ohio, with final integration carried out alongside a small group of partners. Solid rocket motors would come from both Anduril and other suppliers.
The company designed Steelfin’s motor mounting system to accommodate new suppliers while also allowing it to use its own internally developed rocket motors.
