A LARGE VIRTUAL RF APERTURE IS ESTABLISHED VIA A ROTATING TETHER AFFORDING CAPABILITY LEAPS IN SPACE-BASED IMAGING 1-D SPARSE REAL ARRAY ON A RIGID TETHER AND A TETHERED ROTATING ANTENNA ELEMENT CONTINUOUSLY CREATE A VERY LARGE 2-D VIRTUAL ARRAY. ULTIMATE ARRAY SIZE IS LIMITED ONLY BY FEASIBILITY CONSTRAINTS ON LENGTH OF RIGID TETHER. POTENTIAL MISSION APPLICATIONS INCLUDE: PERSISTENT (GEO-BASED) RF EARTH IMAGING (FOR SOIL MOISTURE OCEAN SALINITY SURFACE TEMP. SEA SURFACE WIND ETC.) MAPPING CORONAL MASS EJECTIONS (CMES) FROM A SOLAR POLAR ORBIT ANY RF REMOTE SENSING APPLICATIONS REQUIRING AN EXTRA-LARGE APERTURE MAJOR TASKS CONCEPT VALIDATION AND PERFORMANCE MODELLING ALTERNATIVE APPROACHES EVALUATION MISSION ANALYSIS FOR TECHNOLOGY APPLICATION