English: Convair CV 990 (NASA 810) displaying anti-shock bodies on the top surface of its wings as it sits on the ramp being serviced at NASA's Dryden Flight Research Center, Edwards, California. This aircraft has been modified as a Landing Systems Research Aircraft (LSRA). The space shuttle landing gear test unit, operated by a high-pressure hydraulic system, allowed engineers to assess and document the performance of space shuttle main and nose landing gear systems, tires and wheel assemblies, plus braking and nose wheel steering performance. The series of 155 test missions for the space shuttle program provided extensive data about the life and endurance of the shuttle tire systems and helped raise the shuttle crosswind landing limits at Kennedy.