PROPULSION / Interactive workbench
Work the numbers.
Change one assumption. See what it costs somewhere else. These screening tools make the tradeoffs visible.
01 / ELECTRIC EXHAUST
More speed. Less thrust.
At fixed power, faster exhaust reduces propellant flow but also reduces thrust. This idealized nonrelativistic model assumes a collimated jet and an efficiency that includes conversion into directed exhaust kinetic energy.
F = 2ηP/vₑ; ṁ = 2ηP/vₑ²; a = F/m; Isp = vₑ/g₀. No trajectory, lifetime, installed mass or launch capability is predicted. Example inputs are hypothetical, not measured engine specifications.
02 / HEAT REJECTION
The power has to go somewhere.
Estimate ideal emitting area for a radiator facing a uniform radiative background. Enter heat that actually reaches the radiator, rather than assuming all unused input power becomes onboard heat.
Area counts emitting surfaces. Panel footprint depends on whether one or both faces have a usable view. Real systems also need margins, plumbing and deployment structure.
A = Q/[εσ(T⁴ − Tbackground⁴)]. Omits sunlight, planet view, reflected radiation, conduction bottlenecks, degradation and transient storage.
THE NEXT MOVE / BUILD THE EVIDENCE
A better engine begins
with a better experiment.
Bring a measurement, a materials capability or a mission requirement. Help turn a promising mechanism into a testable design.