The Capital Improvements Branch, or TSSI, is restoring the exhaust gas cooling system of the Aeropropulsion System Test Facility (ASTF), including forespray banks and exhaust cooler, seen here Feb. 14, 2020, at Arnold Air Force Base, Tenn. This effort will enable testing of the next generation of turbine engines in ASTF. (U.S. Air Force photo by Jill Pickett)