availableprocessestoallinvolvedtobeoverlooked. Thus,thedesignershouldbeadvisedtoclarifythe availability ofsuchchannelsforcommunication earlyintheprocessbeforetheyfindthemselves franticallysearchingforadditionalphonenumbersandconference lineswhilethehardwaretheyare investigating isbeingoperatedordiscussedontheTVinfrontofthem. Summary &Conclusions Themanned operation capabilities thatprovedmostusefulduringtheinvestigation andrepairofthesolar arraydeployment anomaly included: •Livevideodownlink capability overportions oftheorbit, •Delayed videodownlink coverage ofthefulldeployment event, •Variable resolution stillphotos ofrequested items,incredibly detailed inspection capability froma camera ontheastronaut's helmet, •Avarietyoftoolsavailable onorbit, •Theabilityofexperienced astronauts tomakesafetyjudgments outside thedesignguidelines, and •Theavailability ofexperienced astronauts andEVAsupport members tobequickly transported to Lockheed Martin toworkasateamwithdesign personnel todetermine appropriate repair procedures. Knowledge ofthesecapabilities andtheirefficient usecangreatly aiddesign engineers inquickly troubleshooting anomalous hardware. Thetechnical limitations ofmostinterest intheSTS-97 solararrayinvestigation werethelimitedtime available forlivevideodownlink andthelimitations inviewanglesandzoomofthefixedvideoandstill cameras. Theadvicetomechanism designers participating infutureinvestigations istobeawareofthe immense valueofthesecapabilities evenwiththeirlimitations andrequest specific instructions or procedures forhowtheavailability oftheseresources isdetermined orrequested. Similar adviceisgiven forunderstanding limitations indealing withotheroperational constraints thatmightbeusefulsuchas eclipse times,spacecraft orientations, control modes, etc.Furthermore, forethought astowhatviews wouldbemostdescriptive cancompensate formanyofthelimitation intheviews. Whensuch considerations mightbecritical, thencommunication ofpreferential viewstotheappropriate chainof command needstobedone.Considerations oftheavailability ofthehelmetcam mayalsoproveuseful. Themostnotable impediments encountered innon-technical areaswere: 1)Thelackofacleardefinition/understanding oftheorganizational structure anddecision making hierarchy oftheverybroadanddispersed setofpersonnel andorganizations involved inthe investigations andoperations, and 2)Alimitedandpoorlydefined downward communication pathtothedesignteamandanevenmore limited andpoorlydefined upward communication pathtotheoperations teamduringcritical events. Certainly, thefranticpaceoftheactivities, complex natureofthemission andthefamiliarity ofthe processes tothoseinvolved regularly inthemallcontributed tothelackofclarityintheseareasforthe designteam.Toprevent suchorganizational andcommunication issuesfromimpeding theprogress ofan investigation, thedesigner shouldbeprepared toaddress suchissuesearlyanddirectly wheninvolved in investigations ofthisnature. Although sometechnical andnon-technical limitations inthemanned operations capability were encountered, thebenefits ofthehumanpresence inthetroubleshooting andrepairoperations allowed for anextremely swiftandfullysuccessful restoration oftheISSsolararraytoitsdesigncapability without impacttosubsequent missions (Figure 9).Therapidcollocation ofskilledandexperience EVAoperations personnel withthehardware designers frommultiple companies combined withtheimpressive arrayofon orbitcapabilities notavailable inautonomous spacecraft operations wasinstrumental inthissuccess. NASA/CP--2002-211506 181