<h2>AAS  96-141</h2><h2>EVALUATION OF THE SHUTTLE ORBIT CONTROL ACCURACY DURING THE SIR-C/X-SAR MISSION</h2><h4>A. Foni, CNUCE Istituto del CNR; C. Canu, Agenzia Spaziale Italiano</h4><h2> Abstract </h2>During the operational phase of the SIR-C/X-SAR Mission (Shuttle flights STS-59 and STS-68), the actual orbit was requested to be known and controlled with a precision exceeding by far the normal Shuttle specification. This paper describes the orbit post-flight analysis performed by X-SAR and the work carried-out at the JSC/Mission Control Center by the Shuttle Navigators and by the SIR-C/X-SAR Mission Operation Team, which allowed the achievement of the scientific objectives well beyond the most optimistic forecasts.<br><br>