How this calculator works
This tool treats a fictional craft as a point mass with user-supplied thrust. Vacuum mode integrates constant acceleration. Air mode integrates F minus quadratic drag during acceleration and reverse thrust plus drag during braking. A stopping trip chooses the switch point so that it reaches rest exactly at the destination. Passenger and engine counts change total mass and thrust. Enter any route as a path length; city routes and interplanetary destinations require their own distance and trajectory assumptions.
Formula
a = F/m; drag = rho Cd A v²/2; V = sqrt(2F/(rho Cd A)). Vacuum stopping trip: t = 2 sqrt(d/a), vmax = sqrt(ad). Air stopping trip: q = tanh(ad/V²), vmax = V sqrt(q), t = (V/a)[atanh(sqrt(q))+atan(sqrt(q))]. Air flyby: t = (V/a) acosh(exp(ad/V²)).
Worked example
A 1 kg model craft with one 1 N engine, no passengers and no drag travels 100 m with symmetric acceleration and braking in 20 s, reaching 10 m/s. A 400 m trip takes 40 s and peaks at 20 m/s.
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Frequently asked questions
Does a craft shape determine its performance?
Not by itself. You need reference area, drag coefficient, mass, thrust and environmental conditions. These are entered explicitly.
Can this model leaving Earth?
No. Leaving Earth requires gravity and orbital mechanics. Vacuum mode is only a straight-line idealization.
Do the results demonstrate unusual propulsion?
No. They show the consequences of your chosen force and mass within standard Newtonian mechanics.