to be confused with legarde lagarde le garde or garde . l.garde inc. type private company industry aerospace founded 1971 founders bill larkin gayle bilyeu alan hirasuna rick walstrom don davis headquarters 15181 woodlawn ave tustin ca 92780 area served worldwide products deployable antennas space propulsion space structures missile defense targets and countermeasures website 1 lgarde also l garde or l garde is an american aerospace and defense technology company founded in 1971 in orange county ca 1 and is the primary contractor for the sunjammer spacecraft the world largest solar sail . 2 the company was an early pioneer of thin skinned multi task inflatable structures used in various military and space applications . 3 at the height of the cold war l garde developed and manufactured inflatable targets and decoy systems for u.s. military defense and countermeasure systems for the strategic defense initiative star wars . 4 after the cold war the company used the technologies and manufacturing techniques it had developed to land a contract to design and build the inflatable antenna experiment 5 6 and other thin film inflatable space structures using its unique application of rigidizable tube technology . 7 the company s unusual name is an acronym formed by the initials of the founding partners bill larkin gayle bilyeu alan hirasuna rich walstrom don davis . the e comes from the latin term et al and others as a tip to other partners and original employees of the company . 1 history edit lgarde engineers took their experience with inflatable structures for military use to space applications around 1992 as a means of controlling the cost of deploying instrumentation into earth orbit and beyond . 8 they studied development work and lessons learned from projects for the united states department of defense and the nasa going back to the 1960s . 9 observing the advantages and challenges of deploying a very large inflatable antenna and other structures in earth orbit using this technology lgarde engineers also observed changes in structural principles when such structures are used in a zero gravity environment and other technical issues arising for large precision structures including surface accuracy analysis and electrical properties . 8 lgarde s first inflatable space structure project was the spartan 207 project also known as the inflatable antenna experiment which was launched with space shuttle endeavour on mission sts 77 may 19 . 1996 . 10 the goal of this mission was to inflate a 14 meter antenna on three 28 meter struts built by lgarde under contract with jpl . the project was developed under nasa s in step technology development program . 11 deployed using the shuttle s remote manipulator system the antenna was successfully inflated and the correct final shape was attained . according to the final mission report the mission was successful and gained a great deal of information about inflating large structures in space . 12 among the points that the spartan 207 project proved was the viability of inflatable space structures as a cost saving concept . the inflatable antenna weighed only about 132 pounds 60 kilograms and an operational version of the antenna may be developed for less than 10 million a substantial savings over current mechanically deployable hard structures that may cost as much as 200 million to develop and deliver to space . 11 lgarde engineers expanded their development of inflatable rigidizable structures with low mass structures strong enough to support orbital large solar arrays as well as much smaller nanosats . 13 among the many detail design parameters they considered were tube design for rigidizable material alternative beam types and designs e.g. trusses material thickness laminates and the best way to resolve euler buckling . 13 a project conducted with jpl under nasa s gossamer spacecraft program in 1999 sought to build an inflatable reflector to concentrate solar energy for space electrical power generation while acting as a large aperture high gain antenna . 14 among the goals of the gossamer spacecraft program was to reduce the mass and stowage volumes of a power antenna while maintaining comparable yield from electrical power generation . 14 additional development came in 2005 when lgarde began utilizing material rigidization methods that provide a long lasting reflector shape without requiring continuous inflation . 15 engineers settled on an aluminum plastic laminate as the rigidization method of choice over cold rigidization of a kevlar thermoplasticelastomer composite as a means of accomplishing two goals 1 diminish stowage space and thereby expanding the potential aperture size of the mirror reflectors and 2 eliminate the need for make up gas needed for purely inflatable reflectors to remain inflated in space . 15 lgarde engineers later advanced the readiness level of the inflatable planar support structure for the gossamer antenna system with additional design analysis testing and fabrication of an inflation deployed rigidized support structure for the waveguide array . 16 going into 2002 lgarde was developing polyurethane resins for a 3 ply composite laminate that could be used in the fabrication of rigidizable structures suitable for use in space . 17 in a paper submitted to the american institute of aeronautics and astronautics aiaa engineers found that such composites can be used to fabricate ultra lightweight deployable rigidizable structures for space applications and that polyurethane was chosen because it could become rigid when exposed to the low temperatures of space . 17 the paper goes on to observe that under nasa s ssp program space solar power truss a 24 foot long inflatable rigidizable truss using polyurethane composites withstood a compression load of 556 pounds 10 % above its designed compression strength while reducing mass of comparable mechanical structures by a factor of 4 . 17 it had been long theorized that solar sails could reflect photons streaming from the sun and convert some of the energy into thrust . the resulting thrust though small is continuous and acts for the life of the mission without the need for propellant . in 2003 lgarde together with partners jpl ball aerospace and langley research center under the direction of nasa developed a solar sail configuration that utilized inflatable rigidized boom components to achieve 10 000 m2 sailcraft with a real density of 14.1 g m2 and potential acceleration of 0.58 mm s2 . 18 the entire configuration released by the upper stage has a mass of 232.9 kg and required just 1.7 m3 of volume in the booster . 18 additional advancement of the solar sail project came as lgarde engineers improved sailcraft coordinate systems and proposed a standard to report propulsion performance . 19 lgarde was selected by nasa to build construct the sunjammer spacecraft currently the world largest solar sail . 20 slated for launch in january 2015 sunjammer is constructed of kapton and is 38 metres 124 ft square with a total surface area of over 1 200 square metres 13 000 sq ft . 20 the ultrathin sail material is only 5 m thick with a low weight of about 32 kilograms 70 lb . 21 once in space the large surface area of the solar sail will allow it to achieve a thrust of about 0.01 n. 22 to control its orientation via this its speed and direction sunjammer will use gimballed vanes each of which is itself a small solar sail located at the tips of each of its 4 booms completely eliminating the need for standard propellant . 22 on october 17 2014 nasa cancelled the sunjammer project after investing four years and more than 21 million on the project . 23 references edit a b lgarde website . lgarde inc. retrieved 21 august 2013 . david leonard 31 january 2013 . nasa to launch world s largest solar sail in 2014 . space.com . retrieved 21 august 2013 . takahashi dean 9 may 1990 . trial balloons l garde plans space art for goodwill games . los angeles times . retrieved 21 august 2013 . christian susan ; cristina lee 24 january 1992 . o.c. s military contractors are vulnerable but hopeful . los angeles times . retrieved 21 august 2013 . nasa chief technologist to visit tustin s l garde inc thursday . nasa news . 9 march 2012 . retrieved 21 august 2013 . cohn meredith 22 may 1996 . technology on the rise tustin firm s inflatable antenna passes a key test in orbit . los angeles times . retrieved 21 august 2013 . lichodziejewski d ; g veal ; r helms ; r freeland ; m kruer . inflatable rigidizable solar array for small satellites pdf . defense technical information center . department of defense . retrieved 21 august 2013 . a b thomas m december 1992 . inflatable space structures redefining aerospace design concepts keeps costs from ballooning . potentials . 11 4 . cassapakis c ; m. thomas 26 september 1995 . inflatable structures technology development overview . aiaa 1995 space programs and technologies conference . aiaa 95 3738 . access date requires url help nasa report space shuttle mission sts 77 . nasa . retrieved 30 december 2013 . a b nasa press kit mission sts 77 . nasa . retrieved 30 december 2013 . mission report spartan project inflatable antenna experiment sp207 iae . nasa goddard space flight center . february 14 1997 . access date requires url help a b derb s b 1999 . case studies in inflatable rigidizable structural concepts for space power . 37th aiaa aerospace sciences meeting . aiaa 99 1089 . access date requires url help a b lichodziejewski d. ; c. cassapakis 1999 . inflatable power antenna technology . 37th aiaa aerospace sciences meeting . aiaa 99 1074 . access date requires url help a b redell f.h. ; j kleber ; d lichodziejewski ; g greschik 2005 . inflatable rigidizable solar concentrators for space power applications . collection of technical papers for aiaa asme asce ahs asc structures structural dynamics and materials conference . 2 . ridell f. h. ; d. lichodziejewski ; j. kleber ; g. greschik 18 april 2005 . testing of an inflation deployed sub tg rigidized support structure for a planar membrane waveguide antenna . collection of technical papers for aiaa asme asce ahs asc structures structural dynamics and materials conference . aiaa 2005 1880 . access date requires url help a b c guidanean k ; d. lichodziejewski 2002 . an inflatable rigidizable truss structure based on new sub tg polyurethane composites . 43rd aiaa sdm conference proceedings . aiaa 02 1593 . access date requires url help a b lichodziejewski d ; b. derb s ; j. west ; r. reinert ; k. belvin ; r. pappa 20 july 2003 . bringing an effective solar sail design toward trl 6 . 39th aiaa asme sae asee joint propulsion conference and exhibit . aiaa 2003 4659 . access date requires url help derbes b. ; d lichodziejewski ; j ellis ; d scheeres 8 february 2004 . sailcraft coordinate systems and format for reporting propulsive performance . aas aiaa space flight mechanics meeting . aas 04 100 . access date requires url help a b wall mike june 13 2013 . world s largest solar sail to launch in november 2014 . space.com . techmedianetwork . retrieved june 14 2013 . david leonard january 31 2013 . world s largest solar sail to launch in november 2014 . space.com . techmedianetwork . retrieved june 15 2013 . a b brooke boen ed . december 16 2011 . solar sail demonstration the sunjammer project . technology demonstration missions . nasa . retrieved june 15 2013 . leone dan 17 october 2014 . nasa nixes sunjammer mission cites integration schedule risk . space news . nasa . retrieved 18 november 2014 . retrieved from https en.wikipedia.org w index.php title lgarde & oldid 663634467 categories aerospace companieshidden categories pages using citations with accessdate and no url navigation menu personal tools not logged intalkcontributionscreate accountlog in namespaces article talk