The LENS I facility can be operated from Mach 6 to 22, and up to velocities of 12,000 ft/sec. This tunnel became operational in 1992 with the major objective of supporting the design and construction of advanced interceptor systems and Scramjet propulsion for vehicles designed to fly at velocities from 6000 ft/sec to 12,000 ft/sec. LENS I is being used extensively by the U.S. Department of Defense and NASA to evaluate the aero-thermal loads on hypersonic vehicles and re-entry capsules. In the LENS I facility, detailed studies have been performed to examine Scramjet performance at Mach numbers from Mach 6 to 12 at duplicated flight conditions with two dimensional and axisymmetric flowpaths. The measurements made using a full-scale X-43 Scramjet flowpath have been successfully compared and validated with live flight data. To perform the aero-optic and radiation analysis of optical seeker heads, a unique suite of instrumentation was designed, and constructed and successfully employed in both the LENS I and LENS II facilities.