International Space Station

Solar Power

Solar ArrayThe most powerful solar arrays ever to orbit Earth capture the sun's elusive energy and begin the process of converting it into power for the International Space Station.

Eight solar array wings will supply an unprecedented 124 volts dc to crew and equipment in the U.S. segment of the ISS. The Space Shuttle and most other spacecraft use 28 volts dc, as will the Russian ISS segment. The higher voltage will meet the higher overall ISS power requirements while permitting use of smaller, lighter-weight power lines.

Each 108.6-ft. long solar array wing will be connected to the ISS's 310-ft. long truss and extend outward at right angles to it. Altogether, they will cover an area of 27,000-sq. ft. about acre. When fully extended, a pair of wings and their associated equipment will span about 240 feet, the largest deployable space structures ever built.

An array consists of two solar cell "blankets," one on either side of a telescoping mast that extends and retracts to form or fold the solar array wing. The mast turns on a gimbal to keep the arrays facing the sun. The gimbal base is integrated with the ISS truss assembly. Additionally, the outboard portions of the truss assembly of the truss assembly also rotate to keep the arrays facing the sun.

A pair of wings and their associated power regulation and power storage hardware is termed a "photo-voltaic module." There are four such modules on the U.S. segment of the ISS at assembly complete.