RT Captain Eli (@TheCaptainEli)Watching 2009 Elon Musk on Charlie Rose casually drop one of the clearest explanations ever about suborbital vs orbital flight:Suborbital (Virgin/Blue Origin style tourism flights):→ Top speed ~ Mach 3→ Roughly 9 units of energyOrbital (real orbit, what SpaceX does):→ Needs ~ Mach 25→ Roughly 625 units of energyWhy? Energy scales with velocity squared → orbital takes ~70× more energy!Suborbital is basically just ~1.5% of the effort needed to actually reach & stay in orbit.He w ...