METHOD FOR RELEASING A DEPLOYABLE BOOM
The present disclosure provides, among other things, a deployable solar array comprising: an array of photovoltaic devices; and a flexible, elongated, rectangular sheet for supporting the array of photovoltaic devices composed of a composite laminate having a predetermined pattern of graphite fiber plies which impart a predefined tension in the planar surface of the sheet so that it curls into a planar sheet with a uniform radius of curvature along its major axis.
1 . A method of deploying an extensible boom from a housing comprising:
providing a support including an array of transducer devices;
mounting the support on a first flexible, elongated, rectangular sheet in a housing, the sheet composed of a composite laminate having a predetermined pattern of graphite fiber plies which impart a predefined tension in the planar surface of the sheet so that it curls into a curvilinear sheet having a uniform radius of curvature along its major axis;
supporting the sheet on a spool in the housing under compression in a stowed configuration; and
releasing the spool so that the sheet unwinds automatically and is deployed from the housing in a linear direction.
2 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the array of transducer devices comprises (i) an array of photovoltaic devices; (ii) an array of semiconductor sensors; (iii) an antenna array; and/or (iv) thermal transfer elements.
3 . A method of deploying an extensible boom from a housing as defined in claim 2 , wherein the transducers are mounted on a polyimide carrier and the polyimide carrier is bonded to the composite laminate.
4 . A method of deploying an extensible boom from a housing as defined in claim 3 , wherein the flexible sheet has a thickness of between 0.1 mm and 0.5 mm, a width of less than 10 cm, and a length of between 10 and 200 cm after full deployment.
5 . A method of deploying an extensible boom from a housing as defined in claim 2 , wherein the array of transducer devices include a first transducer module having a first side dimension, and a second transducer module having a second side dimension different from the first side dimension.
6 . A method of deploying an extensible boom from a housing as defined in claim 5 , wherein each transducer module includes a plurality of discrete photovoltaic solar cells connected in an electrical serial or parallel configuration.
7 . A method of deploying an extensible boom from a housing as defined in claim 6 , wherein the array of photovoltaic solar cell devices includes an array of coverglass-interconnected-solar cells (CICs) mounted on the polyimide carrier by a pressure sensitive adhesive.
8 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the pattern of graphite fiber plies is pre-impregnated with resin and consist of at least intermediate modulus graphite fiber reinforced plies to impart substantially uniform strength, stiffness, and flexibility.
9 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the graphite fiber plies gives the sheet a strength of up to 2.0 g and a stiffness resulting in a natural frequency greater than 0.01 Hz.
10 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the sheet is circumferentially wound to form a spool configuration in a stowed configuration, and forms into a planar cylindrical portion sheet having a uniform cross-sectional curvature as it unwinds from the spool configuration upon deployment to the deployed configuration.
11 . A method of deploying an extensible boom from a housing as defined in claim 10 , wherein the sheet is stored within a one unit CubeSat housing for a space vehicle in its stowed configuration.
12 . A method of deploying an extensible boom from a housing as defined in claim 1 , further comprising:
providing a second flexible, elongated, substantially rectangular sheet for supporting a plurality of transducer assemblies;
supporting the second rectangular sheet in a spooled configuration under compression on a mandrel in a stationary position in a stowed configuration; and
releasing the second sheet from the spooled configuration by releasing the mandrel to allow it to rotate during a deployment operation so that the sheet automatically deploys from the mandrel and curls into a curvilinear sheet having a uniform radius of curvature along its major axis and extending substantially linearly away from the housing.
13 . A method of deploying an extensible boom from a housing as defined in claim 12 , wherein the first and second sheets are substantially simultaneously deployed so that the first sheet is deployed in a first direction from the housing and the second sheet is deployed in the same plane as the first sheet but in an opposite direction from the housing.
14 . A method of deploying an extensible boom from a housing as defined in claim 12 , wherein the housing is disposed in a spacecraft, and the spacecraft is composed of CubeSat modules, wherein the first and second rectangular sheets are stowed within a one unit CubeSat housing.
15 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the housing is disposed in a vehicle.
16 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the housing is disposed within a terrestrial structure.
17 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the radius of the curvature of the sheet is such that the sheet has a depth of not less than 5% nor greater than 20% of the width of the sheet.
18 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the lenticular shape of the sheet is flattened when it is mounted under compression on the spool in the stowed configuration.
19 . A method of deploying an extensible boom from a housing as defined in claim 1 , wherein the housing includes an aperture through which the rectangular sheet is deployed.