Must : MechJeb Near Future Propulsion (ULTIMATE MUST) Krag's Planet Factory CE Kethane HotRockets! Active Texture Management Very useful : NovaPunch Romfarer Kerbin Shuttle Orbiter System Kerbal Universe (PF addon) StarShine Industries Stock-Like Parts Project KSP Interstellar Hooligan Labs Extraplanetary Launchpad Useless but fun : AKS Technologies Sunbeam Lazor HyperEdit (except for testing (thanks Red Iron Crown))