Lockheed Martin announced a lower-cost Patriot interceptor on Monday as militaries seek cheaper ways to counter drones and missiles, while defense contractors face competition from startups making low-cost weapons that can be produced at scale. Lockheed said its new PAC-3 Adapted Capability Effector, or ACE, missile would cost less than half as much as its PAC-3 MSE interceptors, which cost roughly $4 million per missile, according to U.S. Army budget documents.