The U.S. Navy is leading an effort to develop a new version of the Evolved SeaSparrow air-defense missile for the 12 nations in the NATO SeaSparrow Project Office consortium. The Navy’s Sources Sought notice sets an Oct. 19 deadline for companies to respond to the proposed requirements, Defense News reported.

The prospective weapon, identified in the notice as the NSV SeaSparrow, is intended to address a broad range of air and missile threats. Requirements cover targets moving from low to high speeds, flying from sea-skimming altitude to high-diver profiles, and ranging from nonmaneuvering objects to threats capable of high-G maneuvers. The missile also would need to operate against varied target signatures and handle adversary countermeasures.

The effort reflects the demands of a complex naval air-defense engagement. The NSV should protect ships against massed missile salvos while continuing to function in natural, contested radio-frequency, electro-optical and infrared environments. The notice says the missile should be able to “discriminate and resolve between multiple closely spaced targets” and provide threat-track measurements for guidance, navigation and lethality functions.

A graphic included with the notice depicted surface ships, including two aircraft carriers, facing a combination of missiles, torpedoes, a hostile fixed-wing aircraft and a helicopter. The illustration showed friendly ships using active illumination against some threats, while the SeaSparrow used onboard sensors to intercept others.

The design would also be expected to support future changes by the governments participating in the program. The notice calls for a modular, open-source approach and maximum government rights to technical data, computer software, source code, design artifacts and interface specifications. Those provisions are intended to simplify later upgrades, promote interoperability across consortium platforms and help the system adapt to changing threats.

The contractor would provide a complete missile system rather than an individual component. The requested package includes the airframe, propulsion, guidance and software. The missile must be no more than 10 inches in diameter and fit inside a Mark 41 vertical launch tube. Its technical data also must be releasable to the full NATO SeaSparrow consortium.

The consortium members are Australia, Belgium, Canada, Denmark, Germany, Greece, the Netherlands, Norway, Portugal, Spain, Turkey and the United States. Other users of the SeaSparrow system include Thailand and the United Arab Emirates, according to the notice.

The proposed missile would extend a family whose current Block II RIM-162 Evolved SeaSparrow variant is manufactured by Raytheon. The weapon was first fielded in 2004 and is intended as a relatively low-cost defense against anti-ship missiles, aircraft, helicopters and fast attack boats. Its lineage reaches back to the AIM-7 Sparrow air-to-air missile developed in the 1950s. The current Evolved SeaSparrow has an estimated range of about 30 miles.

Production of the existing missile more than doubled to more than 350 rounds in 2025. The new effort would seek a successor able to combine the SeaSparrow’s ship-launched role with broader sensing, tracking and countermeasure capabilities, while retaining a form factor compatible with the Mark 41 launcher and a technical foundation shared across the multinational consortium. The Oct. 19 deadline is the next stated step in the Navy-led effort.