DAMAGE INSPECTION AND VERIFICATION OF TETHERS

CONSIDERABLE EFFORT HAS BEEN DEVOTED BY NASA AND OTHER ORGANIZATIONS COMMITTED TO THE UTILIZATION OF TETHERS IN SPACE. HOWEVER, MOST TETHER DEPLOYMENT SCENARIOS HAVE A COMMON DENOMINATOR--THEY ARE DEPENDENT ON THE REUSABILITY OF SUCH TETHERS IN ORDER TO BE CONSIDERED ECONOMICALLY VIABLE. THE LACK OF DATA ON POTENTIAL FOR TETHER DAMAGE AND THE REQUIREMENT FOR REUSING THE TETHER FOR ECONOMIC REASONS MANDATES THAT A SUBSTANTIAL MARGIN OF SAFETY BE USED, RESULTING IN THE USE OF STRONGER TETHERS TO MINIMIZE POTENTIAL RISKS. THIS IN TURN INCREASES THE TOTAL WEIGHT OF THE TETHER SYSTEM AND HENCE REDUCES IT'S VIABILITY AS AN OPTION FOR MISSION PLANNERS. PROPOSED HEREIN IS AN OPTICALLY-BASED SYSTEM FOR AUTOMATIC INSPECTION AND DAMAGE DETECTION OF TETHERS DURING ACTUAL DEPLOYMENT AND RETRIEVAL. SUCH A SYSTEM WILL PERMIT TETHER SAFETY MARGINS AND WEIGHT TO BE REDUCED IMMEDIATELY. IN ADDITION, THE HISTORICAL DATA OBTAINED AS A CONSEQUENCE OF IN-FLIGHT MONITORING COULD ALLOW NEXT-GENERATION TETHERS TO BE MADE MORE LIGHTWEIGHT. THE PRIMARY OBJECTIVE OF THIS PHASE I EFFORT IS TO DEMONSTRATE THAT AN OPTICALLY-BASED TETHER DAMAGE DETECTION CONCEPT IS FEASIBLE, AND TO PROVIDE THE REQUIRED BASIS FOR CONTINUATION OF THE SYSTEM DEVELOPMENT IN AN ANTICIPATED PHASE II EFFORT.