Selectionoftheminimumclearancebetweenthecoarseconeandbushingwasdrivenbythethermalstructuraldisplacements betweenthecoarsealignmentfeaturesthatarefurthestfromthefixedfine alignmentnut.Oncethisselectionwasmade,acalculation showedthatentryofthefinealignment featureswouldalwaysoccurwiththemaximumclearancebetweenthecoarsealignmentfeatures. Analysisconfirmedthatwiththepredictedthermaldisplacements, dimensional tolerances, andpositional tolerances, whenthecoarsealignmentfeaturesengage,thefinealignmentalwaysbegintoengage,even considering thepotentialforfreeplayassociatedwiththeprimaryracecenteringsprings. OutofPlaneRelative Displacements Manufacturing tolerances andtemperature gradients inandbetween theZ1andP6trusses shifttheoutof-plane (X-direction) positions ofthefinealignment features whentheZ1capture latchisclosedonthe P6capture bar,priortostructural boltengagement. Statedanother way,threeofthefourshearcylinders willseat,butthefourthmightnotbeseated. Theprimary attachbolt'sstroke, boltstrength, contingency attachsleeve stroke, andcontingency attachboltstrength werefoundtobesufficient toseatthefine alignment Z1shearcylinders intheP6receptacles (nuts).Forthistrussattachment system, thecapture latchpreload isnotsufficient toseatthefinealignment Z1shearcylinder intheP6receptacle (nut). Withtheshearcylinder notfullyseated, therecouldbeabolttonutcenterline offsetthatmustbe accommodated byattachbolt'slead-in. Analysis andtestconfirmed thecapability toengage thethreads in thisoffsetcondition. Relative Rotations DuetoWarpa,qe Temperature differences between theZ1andP6mightproduce warpage thatcreates relative rotation between theZ1boltandP6nutassemblies. Theamount oftherotations duetothermal effectswas analytically predicted. Rotational freedom wasprovided inthedesign, intheformofspherical bearings for boththeprimary andcontingency nutassemblies sufficient toaccommodate thepredicted rotations dueto thermal gradients andmanufacturing tolerances. Inaddition, ananalysis concluded thattheon-orbit mechanical loadsdonotrotatethebearing toitstravellimit,thereby confirming thatlocalmoments remain released. Movin.q Element Clearances Analysis wasperformed toensure clearance exists,withworstcasepredicted temperatures, andwith worstcasedimensions, between thefollowing components: Z1shearcylinder outersurface toP6primary ballinsidesurface, Z1contingency boltspacertocontingency bolt,Z1microconical fittingtoprimary bolt, Z1springretainer nuttoprimary bolt,Z1shearcylinder toprimary bolt,ZIlaunchrestraint captohousing, Z1launchrestraint captoshearcylinder, Z1shearcylinder toself-feeding nut,P6balltoracespherical diameters, P6racewidthtohousing, andZ1primary bolttoself-feeding nut.TheZ1launchrestraint nut, showninFigure16,secures theprimary boltfromrattlingduringlaunch, andisremoved bytheEVAcrew onthemission priortoberthing. Verification Program Confidence insystem performance wasachieved through acost-effective collection oftestsandanalyses, including thermal, staticloads,vibration, misalignment, contact dynamics, underwater simulation, andfullscalefunctional testing8.Abalance between testsandanalyses atthecomponent andsystem levels resulted inanintegrated verification approach. Therelationship between component leveltestingand system levelcharacteristics isdescribed foreachtestinthefollowing sections. Qualification Vibration Test Aqualification vibration testwasperformed todemonstrate theabilityofZ1&P6finealignment assemblies towithstand themaximum expected launchvibration environment withaqualification margin. Thiscomponent leveltestcorrelated tosystem levelperformance inthatthevibration spectrums usedfor thetestwerederived fromsystem (cargoelement) levelacoustic tests.Thefinealignment boltandnut assemblies passed allfunctional testsafterbeingexposed tothevibration environments 9. 2O4