Editing Interplanetary spaceflight (section)

====On-orbit tanker transfers====
As of 2019, SpaceX is developing a system in which a reusable first stage vehicle would transport a crewed interplanetary spacecraft to Earth orbit, detach, return to its launch pad where a tanker spacecraft would be mounted atop it, then both fueled, then launched again to rendezvous with the waiting crewed spacecraft. The tanker would then transfer its fuel to the human crewed spacecraft for use on its interplanetary voyage.  The [[SpaceX Starship]] is a [[stainless steel]]-structure spacecraft propelled by six [[Raptor (rocket engine family)|Raptor engines]] operating on [[subcooling|densified]] methane/oxygen propellants.  It is {{convert|55|m|ft|sp=us|abbr=on|adj=on}}-long, {{convert|9|m|ft|sp=us|abbr=on|adj=on}}-diameter at its widest point, and is capable of transporting up to {{convert|100|tonne|lbs}} of cargo and passengers per trip to Mars, with on-orbit propellant refill before the interplanetary part of the journey.<ref name=spacex-itspresentation201609/><ref name=nsf20160927a/><ref name=ars20160918>{{cite news |last=Berger |first=Eric |url=https://arstechnica.com/science/2016/09/spacexs-interplanetary-transport-system-will-go-well-beyond-mars/ |title=Elon Musk scales up his ambitions, considering going "well beyond" Mars |work=[[Ars Technica]] |date=2016-09-18 |access-date=2016-09-19 |archive-date=2016-09-20 |archive-url=https://web.archive.org/web/20160920000810/http://arstechnica.com/science/2016/09/spacexs-interplanetary-transport-system-will-go-well-beyond-mars/ |url-status=live }}</ref>