The House Armed Services Committee has stipulated in the recently approved 2020 defense spending bill, that the Army must seek out a less expensive interceptor for the Patriot system. This follows similar actions by the Polish ministry of defense who signed on to purchase 8 Patriot batteries in 2017. But after seeing the $4 million per round price of the PAC-3 MSE the Polish MoD asked for an alternative. Raytheon obliged by offering a split solution. The first 2 Patriot batteries would be equipped with PAC-3 MSE missiles while the remaining 6 batteries would instead use the much cheaper SkyCeptor, a version of the Stunner missile.
Since 2006 Raytheon has been collaborating with Rafael to develop a replacement for Patriot in Israeli service. This system became operational with the IDF in 2017 under the name David’s Sling, with the missile itself being known as Stunner. As the middle tier of Israel’s ballistic missile defense system, it was key the missile be cheap enough to be bought in large quantities.
In this Raytheon and Rafael succeeded with Stunner reportedly costing below a quarter that of PAC-3. Part of the cost saving is achieved by using conventional aerodynamic control surfaces. In contrast, PAC-3 uses over a hundred micro rockets mounted radially along the missile body to maneuver rapidly. Perhaps Stunners most unique feature is it has both radar and an imaging IR sensor onboard. In theory, the IIR allows for a cheaper radar to be used without much loss in target discrimination.
So is Stunner the solution Congress is looking for? In 2013 it was suggested by Raytheon and Rafael to integrate the Stunner missile into the Patriot system to create Patriot Advanced Affordable Capability-4 (PAAC-4). This would use every subsystem from the existing Patriot system except the launcher. Funding was never put forward and it seems the project was put to bed. Having been revived by the Polish contract, perhaps Stunner will get a second chance with the Army.