US-12627255-B1 - Self-deploying flexible solar array

US12627255B1US 12627255 B1US12627255 B1US 12627255B1US-12627255-B1

Abstract

Provided herein are various enhancements for solar arrays and photovoltaic systems for spacecraft, vehicles, and other applications. In one example, an assembly includes a base layer having a generally circular shape and comprising a plurality of gores interspersed by radial folds. The assembly includes a photovoltaic array coupled to the gores, and a tensioning element configured to apply circumferential tension about a central node of the base layer. The assembly includes a structural element disposed about an outer perimeter of the base layer against which the circumferential tension is conveyed for deployment of the base layer from a stowed configuration into a deployed configuration.

Inventors

John L. GIBB

Assignees

LOCKHEED MARTIN CORPORATION

Dates

Publication Date: 20260512
Application Date: 20241022

Claims (9)

1 . A method, comprising: forming an assembly comprising a photovoltaic array bonded to a circular and flexible base layer having a plurality of gores interspersed by radial folds that define sections, that when folded, establish a stowed configuration for the assembly with an exposed area of one section; forming a tension member positioned in a plane of the base layer that establishes a hoop tension about a center of the assembly that applies radial tension onto a material comprising the base layer for deployment of the assembly from the stowed configuration into a deployed configuration; and forming a perimeter structure disposed about outer circumferential edges of the plurality of gores against which the radial tension is conveyed through the material comprising the base layer to provide passive deployment of the plurality of gores from a stowed configuration into a deployed configuration having the base layer in a generally planar arrangement.
2 . The method of claim 1 , comprising: forming the perimeter structure as comprising joints positioned at the radial folds that provide folding of the base layer into the stowed configuration having an exposed area of a single gore.
3 . The method of claim 1 , wherein the perimeter structure comprises a series of hollow members each corresponding to one of the sections and having a perimeter tension element threaded therethrough; and wherein the perimeter tension element provides a circumferential tension force to unfurl the series of hollow members during deployment of the assembly from the stowed configuration to the deployed configuration.
4 . The method of claim 1 , comprising: establishing the stowed configuration by at least folding the assembly in half over a series of iterations until the exposed area of one section is achieved.
5 . The method of claim 4 , comprising: further establishing the stowed configuration by mounting the assembly onto a boom element such that a portion of the photovoltaic array corresponding to the exposed area of one section is configured to receive solar illumination.
6 . The method of claim 5 , comprising: establishing the deployed configuration by at least releasing the assembly from the boom element responsive to a commanded release of a securing element, wherein the tension member responsively deploys the base layer into the deployed configuration using the hoop tension that applies the radial tension to the base layer and against a perimeter structure deployed about a circumference of the base layer.
7 . A device, comprising: a solar array assembly comprising photovoltaic elements bonded to a circular and flexible base layer having radial folds that define sections, that when folded, establish a stowed configuration for the solar array assembly with an exposed area of one section; the solar array assembly comprising a tension member positioned in a plane of the base layer and configured to apply a hoop tension about a center of the base layer that applies radial tension to a material comprising the base layer for deployment of the assembly from the stowed configuration into a deployed configuration; and the solar array assembly comprising a perimeter structure about circumferential edges of the sections against which the radial tension is applied through the material comprising the base layer to provide passive deployment of the sections of the base layer of the solar array assembly into a generally planar arrangement.
8 . The device of claim 7 , wherein the perimeter structure comprises a series of hollow members each corresponding to one of the sections and having a perimeter tension element threaded therethrough; and wherein the perimeter tension element provides a circumferential tension force to unfurl and interlock the series of hollow members during deployment of the solar array assembly from the stowed configuration to the deployed configuration.
9 . The device of claim 7 , comprising: a boom element onto which the solar array assembly is mounted such that a portion of the photovoltaic elements corresponding to the exposed area of one section is configured to receive solar illumination in the stowed configuration and provide electrical power to at least a portion of the device.

Description

RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 18/171,338, titled “SELF-DEPLOYING FLEXIBLE SOLAR ARRAY,” filed Feb. 18, 2023; which claims the benefit of and priority to U.S. Provisional Patent Application 63/311,752, titled “HUBLESS FLEXIBLE SOLAR ARRAY,” filed Feb. 18, 2022, and which is hereby incorporated by reference in its entirety. TECHNICAL BACKGROUND Photovoltaic cells have been employed to form solar arrays on satellites, space probes, or space vehicles and provide electrical power to on-board systems. However, use of photovoltaic arrays has always been challenging due to the severe packaging, weight, and deployment requirements of launching to space. Typically, rolled or folded solar arrays are packaged to fit into an envelope of a launch vehicle fairing, and then unfurled once in orbit or in space. Various types of compact and deployable solar arrays have been devised over the years. These include umbrella arrays, Scheel fold-type arrays (hub folded “wrap rib”), flat segmented fan arrays, fold-up fan arrays, conic roll-up arrays, Kaplan-type arrays (U.S. Pat. No. 4,030,102), Ultraflex arrays (U.S. Pat. No. 5,296,044), and others. However, all of the aforementioned array types have various drawbacks and limitations. For example, the Ultraflex hub-deployed circular flexible arrays employ complex hubs with many mechanisms and moving parts which do not scale in size easily. One solar array example is the Multi-Mission Modular Array (U.S. Pat. No. 10,546,967), which is a solar array with multiple deployment mechanisms to extend a Z-folding flexible rectangular-shaped blanket, and the blanket is tensioned between two spreader bars. Another solar array example is the Roll Out Solar Array (ROSA) flexible array (U.S. Pat. No. 9,604,737), which is deployed from tightly packed rolls to a rectangular-shaped blanket. The iROSA arrays of the International Space Station employ such technology. However, the ROSA type of arrays remain quite non-rigid and flexible even after deployment, and require a small radius of curvature for the relatively fragile photovoltaic materials while in the stowed configuration, which requires use of a backer foam material which can degrade over time and cause thermal problems in use. Overview Provided herein are various enhancements for solar arrays and photovoltaic systems for spacecraft, vehicles, and other applications. These solar arrays are stowed in a compact, robust, and radially folded configuration for initial transport. Then, the solar arrays can be automatically and passively deployed without the use of motors, servos, or other complex hub mechanisms, such as after a spacecraft has reached a targeted orbit or trajectory. A lightweight “hubless” arrangement is thus employed which includes a base layer membrane tensioned by a central hoop tension member, and further supported by a collapsible perimeter structure. While circular (or generally circular) and hexadecagon-shaped examples are discussed in the included Figures, other shapes can instead be employed using similar materials, techniques, and structures. In one example, an assembly includes a base layer having a generally circular shape and comprising a plurality of gores interspersed by radial folds. The assembly includes a photovoltaic array coupled to the gores, and a tensioning element configured to apply circumferential tension about a central node of the base layer. The assembly includes a structural element disposed about an outer perimeter of the base layer against which the circumferential tension is conveyed for deployment of the base layer from a stowed configuration into a deployed configuration. In another example, a method includes forming an assembly comprising a photovoltaic array bonded to a circular and flexible base layer having radial folds that define sections, that when folded, establish a stowed configuration for the assembly with an exposed area of one section. The method includes establishing, with a tension member, a hoop tension about a center of the assembly that applies radial tension to the base layer for deployment of the assembly from the stowed configuration into a deployed configuration. In yet another example, a device comprises a solar array assembly comprising photovoltaic elements bonded to a circular and flexible base layer having radial folds that define sections, that when folded, establish a stowed configuration for the solar array assembly with an exposed area of one section. The solar array assembly comprises a tension member configured to apply a hoop tension about a center of the base layer that applies radial tension to the base layer for deployment of the assembly from the stowed configuration into a deployed configuration. The solar array assembly comprises a perimeter structure about a circumference of the base layer against which the radial tension is applied during deployment of the solar array assembly. This Overview is pro