TheL7SolarArray TheL7solararray(S/A)isanassembly offourrigidaluminum honeycomb panelsandanaluminum yoke withatotallengthof8.5m(335in).Each25mm(1in)thickpanelweighs approximately 22kg(50Ibm) andis2.27m(89.3in)talland1.88m(74in)wide.AtCDR,theendoflifepowerrequirement withone loststringattheleastfavorable betaanglewas1658W.(Shortly afterlaunch, theoutputwasdetermined tobe2252Wat32.9Vdc.)Eachhingelinelatches intoplaceatfullrotation. Analytical models ofthe arraypredicted afirstresonant modeof0.232Hz. AscanbeseeninFigure1,therearetwohingefittingsperhingeline.Negator springs integral tothe solararray'shingefittingsdrivethedeployment. Thehingesalloperate independently. Deployment time wasoriginally specified totakenolongerthan120seconds withonehingespringfailed.Themostrecent analysis showed thatthefinaldesignprovided anominal deployment timeof30seconds anddeployment in67seconds intheworstcasesinglehingespringfailure. Thesolararraywasfullytestedatthefactory andshipped inthestowed configuration forfinalspacecraft processing atVandenberg AirForceBase, demonstrating oneaspectofthe"shipandshoot"philosophy. SolarArrayR_tralntJRelease System TheS/ARestraint/Release System (RRS)heldthefoursolararraypanelstightlyagainst thesideofthe spacecraft forlaunch. Cablespassing through thepanelswithincup-cone fittingsinthefourpanels squeeze thepanelstogether toprevent gapping ofthepanelsduringlaunch. Onceon-orbit, pyrotechnic cablecuttersinsidethespacecraft arefiredinpairs,releasing thefourpanelsallatonceafterthefinal pairofcablesiscut.Friction isusedintheRRStodissipate thereleased energyofthecutcables. Getting thisfrictionjustrightinthisshockabsorbing devicebecame something ofasmallresearch project, thedetailsofwhichmaybefoundinthereferenced LMSSC documentation. Ground Support Equipment fortheSlA TheMechanical Ground Support Equipment (MGSE) ofgreater interest istheg-negation deployment hardware whichincluded thesekeyitems: 1.adeployment surface, whichinthebeginning, atleast,wasapoured epoxyfloor, 2.foursolararraysupports stands, eachonasetoffourairpads,foratotalof16airpads,and 3.asolararraymounting interface simulator mounted onathree-axis positioner. Thethree-axis positioner wastobecome veryusefulastheneedaroseforunexpected testsetups. The firsttwoMGSEitemsaredescribed ingreater detailinthefollowing pages. Inthebeginning, thedeployment ofthearraywasapurelymanual operation, requiring noElectrical GSE (EGSE). TheEGSEforthesolararraydeployment testinglateronwasquiteanassemblage consisting ofmanyinterconnected spacecraft testcontrolstations. Thefinalsolararraydeployments were commanded through thespacecraft C&DHsystem andassociated flightharnessing, animportant verification testtoassureasuccessful deployment. _Testina Chronoloav FortheL7solararray,whatoriginally wasatesteffortspanning 6-8months became twicethatin duration. Majorschedule impacts totheoverallprogram wereavoided onlybecause theETM+ Instrument hadsuffered itsownproblems inthepowersupplythathadcaused nearlyayear-long delay. Whatfollowsinthissection isjustaquicksummary oftheflightqualification testingefforts. These activities arethenmorefullydescribed towards theendofthispaper. Assembly ofthesolararraywasaccomplishedat theLMSSC EastWindsor plantinNewJerseyinthe Fallof'97.Thedeployment MGSEwaschecked outsimultaneously attheLMSSC KingofPrussia plant nearValleyForge,Pennsylvania. Around thattime,operational difficulties withboththeunevenness of thedeployment floorandthestickiness ofthesupport standairpadsweredismissed bythecontractor as negligible. Thefirstfulldeployment ofthearrayonNovember 6,1997,amanual operation beforeits installation onthespacecraft, suffered asaresult.Corrective actions included additional floorsmoothing andachanging oftheairpads. 214