Space Systems/loral, LLC

California Institute of Technology

Lee Charles Rotlisberger

Dan M Goebel

John Scott Higham

Peter W Lord

David Younghee Oh

Bao Hoang

Christopher Bryan Stell

Jorge Delgado

Gregory Alan Carr

Denis Trofimov

A spacecraft includes a power train that includes a solar array, an electric propulsion subsystem, and a power conversion module. The power conversion module receives power from the solar array at a voltage, V; and delivers power to the electric propulsion subsystem at a voltage, V. The spacecraft is configured to operate at a varying distance, D, from the sun within the range of Dto D, Dbeing at least 1.3&#xd7;D. The solar array is configured to deliver power to the power conversion module at a voltage approximately equal to Vwhen the spacecraft is proximate to D.

Power train for deep space solar electric propulsion

A control system and method that keeps solar arrays on a satellite pointing toward the sun. Exemplary control systems and methods are implemented as follows. An orbit propagator computes satellite orbital location data and computes a sun vector referenced to an inertial reference frame. A coordinate transformation processor processes the sun vector in the inertial reference frame and a sensed satellite attitude signal to generate a sun vector referenced to a satellite body reference frame. A solar array position processor processes a step count derived from a solar array pointing control system and sensed solar array position to generate an estimate of the position of the solar array. A summing device sums the solar array position estimate output, the body frame gun vector, and a bias signal derived from a ground command, to produce a solar array position error signal. A filter filters the solar array position error signal. A current regulator processor processes a measured solar array current to produce another solar array position error signal based on current output. An eclipse processor processes the satellite orbital location data, the solar array position error output signal, and the low pass filtered solar array position error signal to generate a step command. The solar array pointing control system processes the step command to generate control signals that point the solar array at the sun.

Sun seeking solar array control system and method

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San Jose, CA, United States of America

Lee Charles Rotlisberger