There is a need for space-based topographic mapping missions which are an order-of-magnitude less costly than the 100M−classmissionscurrentlyplannedbyNASAandthecommercialcommunity.TheStereoImagingLong−LookSatellite(STILLSAT),havingamassofapproximately100kg,isdesignedfor5minstantaneousfieldofview(IFOV)tomeetmostofthetopographicrequirementsofboththescienceandcartographycommunity.TheresultingDigitalElevationModels(DEM)arepredictedtohave10m(absolute)contourintervals,geo−correctedbygrounddatum.FrameandpanoramiccamerasfromApollo15,16,and17,aswellasESA2˘7sMetricCamerasandtheU.S.LargeFormatCamerahavebeencitedbyphotogrammetristsasadvantageousfortopographicmapproduction.TheuseofaCCDframingcameraforstereoimagingwasdiscussedbyJPLin1979butdismissedbecauseCCDtechnologywasnotyetmatureenough.BycapitalizingonrecentadvancesinCCDtechnologyandinstitutingaconceptofsharedstabilityandpointingresponsibilitybetweenthebusandpayload,itisnowpossibletoconsidersuchanadvancedmission.Thispaperwillfocusonthesystemengineeringtradesresultingfrommissionrequirementsthatdictateearth/satellitemotioncompensationtoachieveveryhighspatialresolution,aswellasoff−axiscrosstrackimagingtomaximizetargetacquisition.Themissionisapproachedfromanintegrateddesignparadigmwhereinscience,instrument,bus,andgroundoperationsobjectivesaresimultaneouslyweighedtoachieveextremelylowcost,lowpower,andreliablemissionelements.TheinitialSTILLSATmissionoperationsplanistoobtainmultiplestereoimagesatbaseheightratiosof1.0withintargets−of−opportunityof100kmindiametertosupportspecificscienceobjectives.STILLSATisdesignedforline−of−sightpointingtowithin0.1degreeandcanimageoff−axisupto20degreesinthecrosstrackdirection.Thetotalspacecraftandmissionoperationscostisexpectedtobewellunder5M (not including launch) and is being initially proposed as a Student Explorer Development Initiative (STEDI) project to the Universities Space Research Association\u27s Advanced Design Program. A launch could occur within 24 months of go-ahead. Progressively advanced concepts of this approach will be discussed, those which can map much larger regions of the Earth through use of larger detector arrays and mosaicked images. It is even conceivable that a STILLSAT-derived single global mapping satellite or constellation of simpler satellites could provide worldwide coverage. This approach holds promise for both scientific and commercial applications