Northrop Grumman Corporation's Ship Systems sector has successfully tested the Low Observable Multifunction Stack (LMS) designed to demonstrate two different advanced exhaust suppresser systems for surface combatants. The exhaust systems, enclosed in a low signature composite structure, also integrate embedded multifunction communication arrays. Service Center. antennas that typically cover the topside of surface combatants," said Schenk. The project was sponsored by the Office of Naval Research through its Advanced Technology Demonstration (ATD) program. Northrop Grumman Ship Systems has been an active participant and ship system integrator on every ATD program related to Topside Integration.