Figure13showstheopeningoftheCoverDriveMechanism underthreeconditions: actualinlg, predictedin0g,andactualduringa"NoOpen"functionaltest.Duringopeninginlg,themaximumtorque of57N-m(504in,lbf)isrequiredatthebeginningoftravel,decreasing intheexpectedsinusoidalshape asthecenter-of-gravity ofthecanistercoverapproaches the90°position.Oncepastthisposition,gravity assiststhegearmotorinopeningthecover.Theweightofthecoverbackdrives thegearbox,which counteracts themotorlossesinthegearbox,andcausestheelectronicstoprovidelesscurrenttoturnthe gearmotor. Thisshowsupinthetorquetraceasanegativeoutputtorqueatthemechanism. Thedrive electronicsareaunipolardrive,onlycontrollingthegearmotortoproducetorqueinthecommanded direction,inthiscase,theopendirection.Whenthegravity-assist fullycancelsthegearmotorlosses,the speedincreasesbeyondtheelectronicsspeedcontrolvalueofabout0.0524rad/s(0.5rpm).The electronics commands nomoretorqueandthemechanism increasesinspeeduntilitcoastsintothehard stop.Thisistheflatpartofthecurveat-13N°m(-115in°lbf)neartheendoftravel.Onceatthehard stop,theelectronicscommands thegearmotortostallagainstthehardstop.Ittakes49secondsforthe covertoopeninlg,whichisfasterthan0goperationbecauseofthegravity-assist. The"NoOpen" functionaltestdurationof65secondsisindicativeoftheon-orbitperformance ofthemechanism. Turning theCoverDrivecouplinginterfacerequiresonlyabout7N=m(62inelbf).Thepredictedopeningtorquein 0gisverylowwithapeakof3.8N*m(33.6in,lbf)occurringinthefirstsecondoftravel.Thispeak representsaworstcaseestimateoftheCoverDriveMechanism torquerequiredtodisengagetheArray LatchcrankfromtheArrayLatchactuatorblock.The0goperationofthemechanism hasatorquefactor ofsafetyinexcessof19. ArrayLatchMechanism Inthestowed position, thefourdeployable arraysaresupported atthreepoints: theADM,thefixed saddle, andthemoving saddle. Thesesupport points(visible inFigure4)areapproximately equally spaced. BoththeADMandthefixedsaddlearemounted ontheinsideofthecanister base.Themoving saddleispartoftheArrayLatchMechanism, whichismounted onthecanister cover.Thisattachment scheme creates theadditional inertialloadthatmakesthetwostifferbending beamflexures ontheLock RingMechanism necessary. Theforcenecessary tooperate theArrayLatchMechanism isprovided by theLockRingDriveMechanism through theactionoftheArrayLatchactuator blockonthecrank.When theLockRingunlocks, theArrayLatchunlatches andthecanister coverisfreetoopen.Theactuator blockismounted ontheLockRingandistherefore attached tothecanister base.Whenthecanister coveropens,thecrankseparates fromtheactuator block.Thisseparation ismission critical. TheArray LatchMechanism mustmaintain itsposition whendisengaged fromtheactuator blocksothatthecrankis abletoreengage theactuator blockwhenthecovercloses. Asthecrankmoves, itdrivesacamshaft that controls themotionofthemechanism. Acamfollower linkispartofthefourbarlinkage thatpositions the moving saddle. Themoving saddleengages slotsineachofthefourarraysbyrotating through alimited angleonasimplepivot.Themoving saddleonitssimplepivotandaportionoftheArrayLatchhousing aretheonlypartsofthemechanism exposed totheinsideofthecanister withitsextreme cleanliness requirements. Thelinkage thatarticulates themoving saddleoperates through aflexible metalbellows thatsealsofftherestofthemechanism fromthecanister interior. Thebellows alsoactsasaspringto holdthecamfollower linkinthecamdetentwhentheArrayLatchMechanism isintheunlatched position. VerylittleoftheLockRingDriveMechanism's torquecapability isusedtoactuate theArrayLatch Mechanism. Thepeakloadoccursattheverybeginning oflatching whenthecamfollower linkiscoming outofthecamdetent. Thiscorresponds tothebeginning oflocking whenthetorquerequired toturnthe LockRingMechanism islow. ADM Thefunction oftheADMistoindependently moveeachofthefourdeployable arraysbetween three locations: stowed, unshaded, anddeployed. Thelattertwopositions areusedforsolarwindcollection andare104°and256°respectively fromthestowed position. AswithalltheotherGenesis mechanisms, theADMisabletoperform inlg.TheADMconsists offourcoaxial drivetubeswithflanges each 2O3