A Novel Rollable, Deployable and Retractable Solar Array Structure

Abstract

A novel structure for a deployable solar array has been develop at DLR that is also able to partially or even fully retract to its initial stowed state. The new array is a flexible blanket design with rollable blanket and boom that are co-axially coiled on the same hub. In contrast to other rollable arrays that use a set of two torsionally flexible booms, a single torsionally rigid boom in the center is used. The array can be realized in a single wing configuration enabling root or tip deployment or a double wing configuration with a shared mechanism and blanket stowage cylinder. The deployment mechanism is also able to fully retract the entire array to its stowed state. A performance analysis reveals high power specific mass and volume values reaching maxima of 227W/kg and 57kW/m³ for a blanket of 1kg/m² of areal mass and 300W/m² areal power. The deployment and retraction of this new solar array is demonstrated in the zero-g environment of a parabolic flight campaign performed in July 2021. The zero-g-demonstrator of the array is a two-wing configuration that is designed for an original size of 8m x 3m but is cut down to 4m x 1.3m to fit into the aircraft’s experiment bay. Within 30 parabolas of the zero-g flight three deployment and retraction cycles are successfully demonstrated. The experiments showed a smooth array deployment and retraction without undesired anomalies.