Significant miniaturemechanism developments areneededfortheseup-and-coming micro-satellite programs. Miniaturization isneededfordeployment ofsolararrays,booms,andinstrument devices. Therearesomeoff-the-shelf mechanisms thataresmall,butthesestillrequireanorderofmagnitude reductioninsizetomeettheneedsformicro-satellites. TheAdvancedTechnology Development Program atJHU/APLiscurrentlyfundingresearchfordevelopment ofminiaturemechanisms andiscollaborating withStarsysResearchtoprovideoff-the-shelf selectionsofthesedevices.Thishasleadtothecreationof theMiniatureMechanisms ToolKit.Thetoolkitcontains6newmechanisms (Table1)foruseon instruments, solararrays,andotherdeployable ormechanism drivendevice.Allofthesemechanisms canbeeasilyscaledforavarietyofoutputrequirements andshowpromiseforadditionalminiaturization. Mechanism Type Micro Sep-Nut Mini Sep-Nut Rotary Latch BurnWire ReleaseActuation Device Shaped SMA Shaped SMA SMA Torsion Sprin9Company Starsys Starsys FuseWire MiniLinear Actuator SMAWireJHU/APL Mini Redundant Shaped Release SMA JHU/APLTable1.Mechanism Descri Mass Size (gm) (mm) 2O Starsys 5 JHU/APL 0.07 0.5 <3.8Power)tions Load Capability LifetimeRelease Time 7.6X5.1X12.7 <2watts 22N>100Actuations -30sec 15.2X15.2X25.4 2-5watts 90N>100Actuations 30-60sec 12.7X12.7X12.7 2-5watts!0.042N-m>100Actuations <15sec 1-2amps 10.2X7.0X3.9 Xvolts 45N 1Actuation <5msec 0.25amps 5.6X5.6X16 8volts 40N>1000Actuations <10msec 10.2X10.2X23 2-4watts 6N>100Actuations 30-60sec Thisproject addressed thedesign ofseveral typesofmechanisms including separation nuts,release devices, linearactuators, androtaryactuators witharangeofloadcapability. Performance requirements forthesemechanisms arenotwellestablished duetotheinfancy ofthemicro-satellite designs. Therefore, assumptions weremadeforrequirements tohandleloadsof12-45N,makethesizesmallas possible, uselowpower,provide lowshock,andmakethemechanisms easilyresettable. ShapeMemory Alloy(SMA)waschosen todrivemostofthemechanisms duetoitscapability ofproviding highforcesina verysmallpackage. SMA'sarealsoveryquickresponding whenelectrically drivendirectly through the material. Aburnwiremechanism wasalsodeveloped byJHU/APL dueitscapability tobehighly miniaturized yetprovide goodstrength capability andreliable operation. Thefollowing sections willgivea detailexplanation ofthesixmechanisms developed. MiniSeparation Nut DesiqnApproach TheMiniSeparation Nutwasdesigned byStarsys tobesimilarinoperation toconventional nutrelease devices andrelease asmallscrew.Thedesignusesasegmented nutconstrained byacollar.Withthe collarinplace,thesegments areheldintheshapeofanut,allowing amating screwtobethreaded and tightened inplace.Thecollarismaintained inposition byacompression springthatprevents thecollar frommoving duetovibration loads.Thecollarisdriveninopposition tothespringbyaSMAelement. To release thescrewandnut,powerissupplied toaheaterordirectly totheSMAelement. Asitisheated through itstransformation temperature, theelement recovers previously induced strain,anddrivesthe collartoallowthesegmented nuttoseparate, releasing thescrew.Whenpowerisdiscontinued, the mechanism canbemanually reset.Thescrewcanthenbere-inserted intothenutandthesequence repeated. TheSMAelement consists of3SMAsprings thatareusedtoaxiallymoveacollarthatrestrains thenut segments (seeFigure2).ThethreeSMAsprings (2)arenestedinacylindrical housing (1).Ontopof thesereststheSpringWasher (4)andcollar(5).Inthelatched position, acompression spring(7) 288