Multiwall Tps - - an Emerging Concept

This iJaper reviews some of the effort required to transform one thermal protection SySUill concept. titanium multiwall, from a conceptual de5ign to a practical working reality. Gradually. frUM continuing analytical and e~pcrimental studies, a fundamental understanding :)f the therrna 1 and s t ructu ra 1 performance of the ba~ic lIIultil~all concept is evolving. In addition, radiant heat. wind tunnel, vibration, acoustic and 1 iglltning strike tests are being used to verify the performance of Inultiwall ti les under representative operating conditions, and flight tests of a large array of tiles are planned as pdrt of an orbiter experiments program. Results of UJe tes ts are bei ng used to improve the design,dnd a mature technology is emerging. To date, resedrch has focused on flat all titanium llultiHall configurations, \~hich are limited to temperatures belo~t 810 K (lOOO°F); however, the effort is being extended to include curved surfaces and hig'ler temperature versions of the :nulthtall concept. Preliminary estimates indicate that these concepts, which offer the inherent durability of metallic systems, are mass competitive with the insulation system currently employe(j on the Space Shutt 1 e Orbiter.