hasbeencalled.Theintentofthesimulation,usingthesystemmodel,wastopredictthebehaviorofthe trussinterfaceandtheSRMSastheCLAdrawstheP6andZ1trusses together toamated, pre-loaded condition, afterwhichtheprimary boltattachfeatures areengaged. Thetestingofasinglecorner's fine alignment feature, i.e.,thecomponent level,allowed identification ofdetailed alignment characteristics that wouldotherwise bemasked bysystem leveltesting. Aspecially designed testsetupwascreated consisting ofaplatform supported bystrutsthatwereeach instrumented withadisplacement andaxialloadtransducer. Theplatform heldtheball-nut halfofthefine alignment feature andanXYZtableheldtheshearcylinder feature abovetheball-nut (seeFigure18).The XYZtablewasusedtocreatealateralmisalignment between thetwofeatures whiletheywereapartfrom eachother.Thetablewasthendrivendown,causing thetwofeatures toengage andforcingtheplatform tocomply viadisplacement ofthestruts.Strutloadsanddisplacements wererecorded asafunction of timeforcorrelation withasimulation oftheentiretestsetup. Afterbeingcorrelated tothecontact dynamics testresults, thesystem modelwasdeveloped andusedfor several studiesis.First,handselected initialmisalignment conditions wereusedtoexamine the boundaries ofthecapture envelope. Then,treating themaximum misalignment valuesasthree-sigma conditions generated probabilistic initialconditions. Theinitialconditions werescreened formeeting the readytolatchcriteria. TheRTLcriteriaitselfwasdetermined through aseriesofstudies whichultimately resulted intheoneusedon-orbit, i.e.thatallfourP6coarsealignment conetipsbeplacedatorbelowthe planeoftheZ1coarse alignment bushings. Inallthesimulated cases,theP6andZ1trusses were successfully brought together bytheCLAandtheinterfaces fullyseated, evenwiththeSRMSinBrakes OnMode.Thecoarse andfinealignment features oftheinterfaces werealways abletoremove initial misalignments completely, followed bypre-loading oftheinterface bytheCLA.Theworstcasetravel pathsdefined bythesimulations wereusedtoperform acomputer aideddesign clearance study.This analysis confirmed thatnointerference toberthing exists.Additional berthing simulations wereperformed toshowthatberthing canbeachieved usingthestrapsandwinches, mentioned earlier,intheeventthe capture latchcannotbeoperated _. Underwater Testinq FullscaleZ1&P6segment mockups werebuilttophysically simulate trussmodule interfaces andthe capture mechanism. Thesemockups weremadeneutrally buoyant andplaced underwater inamassive tank.Space suitedastronauts demonstrated theycouldconveniently reachandoperate thetruss attachment mechanisms insimulated weightless conditions _6.Thisdemonstration provided confidence thatthemechanism wouldworkintheZ1toP6application. Acceptance PhaseComponent Testinq Functional testswereperformed duringassembly oftheindividual Z1boltassemblies. Checks ontheZ1 boltassemblies included verifying lockpinoperation intheprimary boltlaunch restraint, operation ofthe contingency spacer lock,andoperation ofthecontingency spacer. Because theP6nutelements are integral withthetrusscornerfitting,theywereverified afterinstallation intheP6truss.Careful dimensional inspections duringdetailpartfabrication andduringassembly ensured mechanism performance wasas intended. Suchinspections werepossible, andtherefore theusualmechanism thermal vacuum and vibration acceptance testswerenotneeded. Acceptance PhaseFullScaleTestinq Functional testsandinspections wereperformed aftertheboltassemblies wereinstalled ontheZ1and afterthenutelements areinstalled intheP6.Manyofthesechecks wereperformed usingtheMating Mechanism Simulators (MMS). TheZ1MMSisaninspection toolthatcontains simulated Z1features for checking theP6flightarticle(seeFigure19).TheP6MMSisaninspection toolthatcontains simulated P6 coarse andfinealignment features andisusedtochecktheZ1flightunitfeatures (seeFigure20). Measurements takenusingtheMMSunitsverified thatthemanufacturing tolerances ontheflightarticle's alignment features werewithintheallocated values. Withthatconfirmation, confidence wasgained that therewouldbesufficient racefloatandcoarsealignment feature clearance toaccommodate theexpected on-orbit thermal deflections. TheMMSmeasurements wereaugmented withlasertheodolite andcameracomputer system measurements _z. 206