Bringing an Effective Solar Sail Design to TRL 6

Abstract

Solar sails reflect photons streaming from the sun and convert siirne of the energy into thrust. This thrust, though small, iii continuous and acts for the life ofthe mission withrrut the need for propellant ('I. Rccent advances in sail mjiterials and ultra-luw mass structures have rnabled a host of urefiil mirrions utilizing solar :;ail propulsion. .The team of L'Garde, Jet Propulision Laboratories, Ball Aerospace, arid Langley Research Crnter, under the direction of NASA, has been developing a solar sail configuration to address NASA's tiihlre space propulsion needs. Utilizing inflatable deployed and Siih Tg rigidized hoom components, this sailcraft achieves an areal density of 14.1 s/m' a'nd a characteristic acceleration of 0.58 mrnls' The entirc configuration released by the upper s a g e has a mass of 232.9 kg and requires just 1.7 r d of volume in the booster. After deploynient, 92.2 kg of non-flight rcquircd equipment is jettisoned resulting in a sailcraft mass (with payload and coniiol system) of 140.7 kg. 'This document outlines the accomplislinieiits of a Phase I effort to advance the technology readiness level (TRL.) 01 the co!ncept from 3 townrd a TRL of 6. The P'lase I cffart, the first of tliree piripused phases, addrerised the: design of the solar sail, its application tcl several missions cumntly under review at NAS,A, and developed a ground test plan to bring the techrlology toward a TRL of 6. h=ct ion Early in the ]program:, with the support of NASA, solar sail niissions under consideration were rcseerched ;and a mission set of interest was developed Relevrint mission parameters and Copyright 200:; by L'Garde Inc. Piihlished by The American Institute of Aeronautics and A s t r o l l a~t i~~, lnc with permission ~-environs were identified and defined. These rcquirements were used to refine a solar sail design meeting and exceeding these requirements. This design includes all elements required for powagcncration, communications, and navigation. An equipment list WAS generated, components selected, and mass properties developed. To enhance the flight performance of the concept, a carrier concept was developed to jettison all non-essential

Review of Inflatable Booms for Deployable Space Structures: Packing and Rigidization

“…Inflatable conical booms were developed by L'Garde for the NASA In Space Propulsion (ISP) project [5,66], and the concept was space-qualified on the Cibola Flight Experiment, in combination with a sub-T g rigidization technique [67]. In order to improve the straightness of deployment, a mandrel can be placed at the narrow end of the conical boom, providing a stiff surface for the material to roll on [64,65].…”

“…The relatively low Technology Readiness Level (TRL) of space inflatables does not reflect the extensive research and development that has taken place over the years, and inflatables remain a promising technology 1 Research Associate, Cambridge University Engineering Department; m.schenk@cantab.net 2 Research Associate, Cambridge University Engineering Department; viquerat@cantab.net 3 Senior Lecturer, Cambridge University Engineering Department; kas14@cam.ac.uk 4 Reader, Cambridge University Engineering Department; sdg13@cam.ac.uk for a wide range of space applications. Of particular relevance are inflatable cylindrical structural elements, often referred to as booms; these can make up space trusses [3], support the reflector of an inflatable antenna [2], or form the structural framework for solar arrays [4] and solar sails [5].…”

Flexible Models for Solar Sail Control

“…Much progress has been made during the last few years toward completing the vision of solar sail development [1]. Two primary design concepts have emerged for a square solar sail supported by four booms radiating from a central hub [2,3]. These concepts differ in the details of sail attachment to the booms, in the design of the booms themselves and in their approach to attitude control.…”

“…One design includes four scalloped-edge sails with multi-point attachments along telescoping booms constructed of inflatable isogrid sections. Angular positioning of the sail is accomplished via adjustable vanes at the tips of the booms that can be oriented to use the solar pressure to change the solar sail orientation [2]. The other design includes sails that are attached to uniform booms at only five locations: the hub and the four boom tips.…”

Design Considerations for an Integrated Solar Sail Diagnostics System

“…[1][2][3] Both are 4-quadrant, square sail designs with four lightweight diagonal booms (linear density < 100 g/m 2 ) and ultra-thin membranes (areal density < 10 g/m 2 ) as shown in Fig. 1.…”