Transformational Solar Array for Extreme Environments

This project is to develop a very high performance solar array for use in extreme environments typically exemplified by trajectories to and orbiting Jupiter. The environments are low temperature, about -125 C; low irradiance, about 50 W per square meter, and high charged particle density. The project array is also intended to have very high performance in earth orbit. Perhaps the single best measure for such arrays is the watts developed per kilogram of array. Under standard test conditions, the proposed array will develop over 250 W per kg under compared to 60 W per kg for state of the art arrays. The relative performance between the two arrays diverges even more for use in extreme environments. The array will use concentrators to reduce cost and will be well set for automated production, which is generally not the case for existing solar arrays. The array will use very high efficiency six junction Inverted Metamorphic (IMM6) solar cells. These assist in the development of the smallest possible array. This translates into better mechanical performance and better view factors on a spacecraft. The goals for this project are to design and demonstrate at TRL-5 an array with: • Over 47% Beginning of Life cell efficiency at 5 AU and -125 °C • Over 32 % End of Life efficiency at the blanket level at 50 W m-2, -125 °C and 4E15 1 MeV e cm-2 • Over 8 W kg-1 at EOL for the entire array including structure and deployment mechanisms • A stowed packaging density of 54 kW m-3 • An ability to survive launch and numerous deploy retract cycles without degradation • An output higher than 300 V • An ability to operate in a plasma generated a by xenon thrusters, typically 1E8 cm-2 ions with an average energy of 2eV • A design compatible with electrostatic and magnetic cleanliness • Record breaking IMM6 solar cells • IMM solar cells that have no anomalous flat spot behavior at low irradiance and low temperature • A mock-up production line for the inexpensive manufacture of spacecraft blanket arrays. More »