THE VECTOR INTERFEROMETRY SPACE TECHNOLOGY USING AERO (VISTA) MISSION IS A 90 DAY CUBESAT MISSION IN A POLAR ORBIT THAT WILL ADVANCE OUR ABILITY TO PERFORM RADIO INTERFEROMETRY USING CUBESATS IN SPACE. THIS MISSION IS A TECHNICAL PATHFINDER THAT LEVERAGES THE NASA LCAS AURORAL EMISSION RADIO OBSERVER (AERO) CUBESAT PROJECT BY DUPLICATING THAT SATELLITE IN A BUILD-TO-PRINT MANNER. VISTA WILL LAUNCH AT THE SAME TIME AS AERO. THE EXPERIMENT WILL USE THE TWO CUBESATS IN ORBIT AND COMBINE THEM WITH GROUND BASED BEACONS AND RECEIVERS TO DEMONSTRATE THE PERFORMANCE ADVANTAGES OF VECTOR SENSOR INTERFEROMETRY (VSI) RELATIVE TO CONVENTIONAL APPROACHES. CONTROLLED EXPERIMENTS WILL BE PERFORMED EARLY IN THE AERO MISSION LIFETIME SO THAT THE DATA COLLECTED CAN ALSO CONTRIBUTE TO THE ON ORBIT AERO CALIBRATION AND VALIDATION EFFORT. ..FOLLOWING THE INITIAL SPACE INTERFEROMETRY DATA COLLECTION THE VISTA SATELLITE WILL PERFORM PRIMARY ACTIVITIES TO COLLECT DATA RELEVANT TO RISK REDUCTION AND PLANNING FOR FUTURE LOW FREQUENCY HELIOPHYSICS RADIO CONSTELLATION MISSIONS. THESE INCLUDE COLLECTION OF RAW DATA WITH THE AERO SPACECRAFT OVER THE AURORAL ZONE FOR INTERFEROMETRIC ANALYSIS AND IMAGING OF AURORAL KILOMETRIC RADIATION (AKR). THESE MEASUREMENTS CAN AUGMENT BOTH EVENT COVERAGE THE ANGULAR RESOLUTION AND THE TIME RESOLUTION OF AERO MEASUREMENTS. THEY WILL ALSO PROVIDE DATA TO TEST ALGORITHMS FOR INTERFEROMETRIC MEASUREMENT OF AURORAL RADIO EMISSIONS FROM ORBIT. VISTA WILL ADDITIONALLY IMPLEMENT PERIODIC SAMPLING OF THE LOW FREQUENCY RADIO ENVIRONMENT IN ORBIT TO CHARACTERIZE SIGNALS DIRECTIONS OF ARRIVAL AND THE ABILITY TO NULL STRONG SIGNALS USING THE VECTOR SENSOR. THE NULLING CAPABILITY IS CRITICAL FOR OPERATION OF A LOW FREQUENCY SATELLITE CONSTELLATION NEAR TO THE EARTH AS OPPOSED TO A MORE ISOLATED LOCATION SUCH AS ON THE LUNAR FAR SIDE. ..OUR TECHNICAL APPROACH IS TO USE THE UNIQUE CAPABILITIES PROVIDED BY THE ELECTROMAGNETIC VECTOR SENSOR (EMVS) PLANNED FOR THE AERO MISSION. THIS SENSOR PROVIDES THE ABILITY TO MEASURE ANGLE OF ARRIVAL AND POLARIZATION INFORMATION FROM A COMMON RF PHASE CENTER USING SIX ORTHOGONAL DIPOLE AND LOOP ANTENNAS. THE INFORMATION AVAILABLE FROM THE VECTOR SENSOR CAN BE USED TO ENABLE FUTURE INTERFEROMETRIC CONSTELLATIONS WITH LESS THAN HALF THE NUMBER OF SATELLITES WHEN COMPARED TO TRADITIONAL DIPOLE OR TRIPOLE ANTENNA BASED SYSTEMS. THIS IS DUE TO THE INCREASED DEGREES OF FREEDOM AVAILABLE THAT ARE INHERENT IN AN RF SENSOR MEASURING THE FULL INFORMATION CONTENT OF AN ELECTROMAGNETIC WAVE. DEMONSTRATION OF VECTOR SENSOR INTERFEROMETRY AND IMAGING IS A KEY NEXT STEP BEYOND AERO. ..THE VISTA MISSION S DATA ACQUISITION STRATEGY WILL BE SIMILAR TO THE AERO SATELLITE BUT WILL FOCUS ON OBTAINING ADDITIONAL RAW RF VOLTAGE LEVEL DATA. THE DATA THAT ARE COLLECTED WILL FOCUS ON INTERVALS THAT ENABLE DEMONSTRATION OF KEY INTERFEROMETRIC MEASUREMENTS. TO ACCOMPLISH THE DATA COLLECTION WE WILL DOUBLE THE USE OF THE MSU SYSTEM AND ENABLE THE 18M WESTFORD RADIO TELESCOPE AS AN S-BAND GROUND STATION. GROUND BASED ASSETS WILL ALSO BE USED TO PROVIDE A CONTROLLED RADIO BEACON AND ADDITIONAL INTERFEROMETRIC BASELINES. IN PARTICULAR THE USE OF BOTH SPACE AND GROUND BASED BASELINES MAY ENABLE US TO PROVIDE CLOSURE PHASE AND AMPLITUDE CALIBRATION FOR THE MEASUREMENTS WHEN IONOSPHERIC REFRACTION IS PROPERLY MODELED. FROM A HELIOPHYSICS TECHNOLOGY PERSPECTIVE SPACE RADIO INTERFEROMETRY IS NECESSARY FOR SCIENTIFIC INVESTIGATION OF RADIO EMISSION FROM THE SOLAR CORONA INNER HELIOSPHERE AND ALSO EMISSIONS FROM OTHER PLANETARY BODIES IN THE SOLAR SYSTEM SUCH AS THE EARTH JUPITER AND SATURN. .
$3,748,919FY2020National Aeronautics and Space AdministrationNASA
Massachusetts Institute Of Technology, Cambridge MA