Automating Separation System Reliability Testing , RyanL.Perroy Abstract Thispaperpresents thedevelopment, execution, andresulting testdataofanautomated separation reliability testprocedure fortheLightband separation system. Theautomated procedure wasdeveloped to exploitthe"easy-to-test" designoftheLightband andresulted inaturnaround timeoftenminutes between successive separation tests.Theautomated testprocedure wasusedsuccessfully forseveral different Lightband separation systems, including a45.72-cm (18-in)hexagonal Lightband builtfortheNanosat program anda66.04-cm (26-in) Lightband builtandrecently launched fortheStarshine-3 satellite program. Aconcise description oftheLightband andthetestset-upispresented, including discussion of air-bearing assemblies, angular ratesensors, linearposition transducer, satellite mock-up andmass properties, instrument calibration, LabVIEW program andcode,dataflow, electrical circuithardware, and electrical signalnoiseandconditioning issues. Separation reliability testresultsarepresented, alongwith adiscussion oflessons learned. Introduction Traditional methods ofdetermining thereliability ofseparation systems generally consist ofsuspending theengaged system abovethefloor,triggering aseparation event,andallowing thedeployed separable section tofallduetotheforceofgravity. Instruments tocharacterize tip-offratesarerarelyused,and measuring accurate rotational andtranslational separation ratesmaybeimpossible asgravitational torques candominate system dynamics. Traditional separation testsaregenerally time-consuming. Itmay takeseveral daystosetandresetV-bands forseparation tests,andrequire the;oversight ofseveral engineers andtechnicians. Separation testingmayalsobedangerous, involving explosives andsystems atlevelsoftension reaching 8900N(2000Ib).Mechanical fatigue mayalsobeafactorinseparation reliability testing. ManyV-band systems maytolerate asfewastencyclesbeforepotentially becoming unsafetooperate duetofatigue oftheband.Allofthesefactorscombine tomaketraditional separation reliability testing expensive, difficult, andinfrequent. Acomparison ofmethods ofdetermining separation reliability isshowninTable1. Table1.Comparison ofSeparation Reliability Determination Methods :!:i_'_thbd_;Of:De_e_m!inln_ i_;_;,:.ji__V_i_e_ _:':rPitch,Rolila_d"Y'aw_ Ii_;rra_ia_io_aii_l _.,_Nullifi:cation of_Statistically .........,,,..... i .... ......... ......•Separation :Reliability ::_:..!.::_separation. ,_Angular rates_i:.-/:i__VelOcity-_., GraVitational Forces IMeaningful Data Automated Separation Reliability TestFixture Traditional Methods of Determining ReliabilityYes YesYes NoYes NoYes NoYes No Theseparation reliability testfixturewasdesigned tonotonlytestLightband separation reliability, through quickly triggering successive andhighlyrepeatable separation events, butalsotocharacterize the separation eventitself.Air-bearings wereusedtoeliminate friction andgravitational torques, and additional massandoutriggers wereaddedtothefixturetomatchthemassproperties oftheplanned Planetary Systems Corporation, SilverSpring, MD Proceedings ofthe36thAerospace Mechanisms Symposium, GlennResearch Center,May15-17,2002 NASA/CP--2002-211506 279