With a number of successful Falcon booster landings behind it, SpaceX is getting ready to try something likely to be a bit more challenging: three nearly simultaneous landings. This doesn’t mean SpaceX is upping its launch schedule; instead, the three boosters will all be part of the planned Falcon Heavy vehicle.
Essentially three standard Falcons strapped together, the big rocket will be capable of lifting 54 metric tons into orbit.
54 metric tons. Think of what a half-dozen launches per year atop these re-usable Falcon boosters could put into orbit. A shipyard for building and re-plenishing a Mars transfer vehicle, perhaps?
Consider that the simplest and most crew-friendly way to get to and from Mars is a large, well-provisioned craft that never need enter or leave an atmosphere or gravity well. Without the need of an aerodynamic shape or structural strength beyond what can hold together in a low-Earth and low-Mars orbit (think International Space Station), a craft could be arbitrarily large and capable of attaching multiple cargo and fuel modules. The only limiting factor is the point of diminishing returns, where you’re just hauling more fuel to transport the mass of more fuel.
Said vehicle would orbit Earth as it’s built, outfitted, tested and, eventually, fueled. A de-orbit burn puts into elliptical orbit from which it slingshots out to Mars, where an equivalent burn tucks it into orbit there. Cargo modules may be de-orbited to future human landing sites. Human-capable modules may be de-orbited to bring us to the surface for habitat construction and ascent back to the transfer vehicle. The transfer vehicle itself is never more than a large, modular and comfortable bus for the commute back and forth between planets.
Just spitballing here. An idea like this no doubt exists somewhere. Execution begins with heavy-lift rocketry, and that becomes affordable with re-usable launchers. We already have those.
A Random Stroll 