Accession Number : ADA182589

Title :   Computer Modeling of High-Voltage Solar Array Experiment Using the NASCAP/LEO (NASA Charging Analyzer Program/Low Earth Orbit) Computer Code.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Reichl,Karl O. , Jr

Report Date : JUN 1987

Pagination or Media Count : 211

Abstract : This thesis predicted interactions between the Interactions Measurement Payload for Shuttle (IMPS) flight experiment and the low earth orbit plasma environment. Two interactions (parasitic current loss and electrostatic discharge on the array) may be detrimental to mission effectiveness. They result from the spacecraft's electrical potentials 'floating' relative to plasma ground to achieve a charge flow equilibrium into the spacecraft. The floating potentials were driven by external biases applied to a solar array module of the Photovoltaic Array Space Power (PASP) experiment aboard the IMPS test pallet. The modeling was performed using the NASA Charging Analyzer Program/Low Earth Orbit (NASCAP/LEO) computer code which calculates the potentials and current collection of high-voltage objects in low earth orbit. Models are developed by specifying the spacecraft, environment, and orbital parameters. Eight IMPS models were developed by varying the array's bias voltage and altering its orientation relative to its motion. The code modeled a 'typical' low earth equatorial orbit. NASCAP/LEO calculated a wide variety of possible floating potential and current collection scenarios. These varied directly with both the array bias voltage and with the vehicle's orbital orientation.

Descriptors :   *COMPUTERIZED SIMULATION, *ARRAYS, *SOLAR PANELS, *PHOTOVOLTAIC EFFECT, BIAS, VOLTAGE, CHARGE TRANSFER, EQUILIBRIUM(GENERAL), COLLECTION, SCENARIOS, ELECTRIC DISCHARGES, FLOATING BODIES, HIGH VOLTAGE, COMPUTER PROGRAMS, ELECTRICAL PROPERTIES, FLIGHT TESTING, MEASUREMENT, PAYLOAD, EARTH ORBITS, LOW ORBIT TRAJECTORIES, LOSSES, PARASITES, GROUND LEVEL, PLASMAS(PHYSICS), SPACECRAFT, INTERACTIONS, EQUATORIAL ORBITS, ORBITS, MODULAR CONSTRUCTION, SPACE SYSTEMS, PALLETS, ORIENTATION(DIRECTION), VEHICLES

Subject Categories : Electric Power Production and Distribution
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE