To go 20 miles you'd have to launch faster than the speed of sound https://www.amesweb.info/Physics/Projectile-Motion-Calculator.aspx https://www.amesweb.info/

To go 20 miles you'd have to launch faster than the speed of sound https://www.amesweb.info/Physics/Projectile-Motion-Calculator.aspx https://www.amesweb.info/Physics/Projectile-Motion-Calculato... It's hard to think of a use case..... These days with the transitive nature of people, islands are going to have boats going to them frequently enough proportionally to the people on them such they can deliver goods cheaper. Information is wireless, the original reason for rocket mail I assume. Even reducing it to something sensible like an art project for a Burning man style event, firing a burrito (Search burrito cannons) 1 km away could still knock someone off their bike and hurt them plus it'd be inaccurate due to wind, rising heat, so a pointless project. You could of course fire vertically, expand out, then glide the delivery in accurately or parachute it down with guidance but you'd lose the delivery vehicles electronics = $. Maybe pick up, clip in clip out electronics to reuse at the end of the night across town, have a deposit for the buyer and reward for the collector.