“Big, fat, juicy targets”— the problem with existing early-warning satellites. And a solution.

In 2018, the US Air Force announced its intention to cancel the seventh and eighth space vehicles in the Space-Based Infrared System (SBIRS) program—a collection of satellites that provides early warning of incoming missiles—and declared its desire to transition over to the Next Generation Overhead Persistent Infrared program, which will serve the same purpose but which proponents say will be less expensive and more robust. Indeed, it was the escalating costs and vulnerability to countermeasures that seem to have motivated the decision to terminate the SBIRS program. More

(Source: Bulletin of the Atomic Scientists - Oct 1)