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One of the factors needed to describe the handling characteristics of the Space Shuttle Orbiter during the landing rollout is the response of the vehicle's tires to variations in load and yaw angle. An experimental investigation of the cornering characteristics of the Orbiter main gear tires was conducted at the NASA Langley Research Center Aircraft Landing Dynamics Facility. This investigation compliments earlier work done to define the Orbiter nose tire cornering characteristics. In the investigation, the effects of load and yaw angle were evaluated by measuring parameters such as side load and drag load, and obtaining measurements of aligning torque. Because the tire must operate on an extremely rough runway at the Shuttle Landing Facility at Kennedy Space Center (KSC), tests were also conducted to describe the wear behavior of the tire under various conditions on a simulated KSC runway surface. Mathematical models for both the cornering and the wear behavior are discussed.

Scale model studies of the Shuttle Orbiter Arrestment System have been completed. The system was tested with a 1/27.5 scale model at the NASA Langley Research Center and a 1/8 scale model at All American Engineering Company. The purpose of these studies was to determine the proper net arrestment system configuration to bring the Orbiter to a safe stop in the event of a runway overrun with minimal damage. Tests were conducted for centerline engagements and off-center engagements at simulated speeds up to 95 knots full scale. The results of these studies defined the net-orbiter interaction, corrections to prevent underwing engagements, corrections necessary to prevent net entanglement in the main gear, the dynamics of off-centerline engagements, and the maximum number of vertical straps that might become entangled with the nose gear.

One of the factors needed to describe the wear behavior of the Space Shuttle Orbiter main gear tires is their behavior during the spin-up process. An experimental investigation of tire spin-up processes was conducted at the NASA Langley Research Center's Aircraft Landing Dynamics Facility (ALDF). During the investigation, the influence of various parameters such as forward speed and sink speed on tire spin-up forces were evaluated. A mathematical model was developed to estimate drag forces and spin-up times and is presented. The effect of prerotation was explored and is discussed. Also included is a means of determining the sink speed of the orbiter at touchdown based upon the appearance of the rubber deposits left on the runway during spinup.