The second stage solid rocket motor being developed for the Next Generation Interceptor (NGI) program was successfully static fired inside a facility representing conditions in low-Earth orbit, demonstrating its ability to maintain the “extreme thermal and pressure stresses” in a key milestone toward eventual operation in the missile defense mission, Lockheed Martin [LMT] said on Monday. The NGI is being developed by Lockheed Martin for the Missile Defense Agency’s Ground-based Midcourse Defense system. L3Harris Technologies [LHX] is developing the first…