Patched Conic

You are a freelance pilot working a single ship, a fragile budget, and a logbook full of jobs nobody else will fly. Haul cargo and passengers between stations, prospect bodies for ore and ice, stand up surface refineries, build out a fleet, and take on the megamissions that earn a name out past the frost line.

Every trajectory you fly is one a real spacecraft could fly. There is no "go to planet" button. The propagator never cheats on your behalf.Real orbital mechanics, not an approximation

The simulation is built on a closed-form two-body propagator and a patched-conic sphere-of-influence model — the same baseline mission designers used in the Apollo era and still use today for first-order trajectory work.

Kepler's equation solved every tick with a Danby starter and Newton–Raphson iteration; the hyperbolic form handles escape and flyby trajectories

Lambert's problem solved with Izzo's 2015 universal-variable algorithm and a Householder iterator — a porkchop search over departure and arrival dates picks the minimum-Δv window, the same way NASA's Trajectory Browser does

Hohmann transfers compute the phase angle and Δv for the cheapest two-impulse hop between circular orbits

The vis-viva equation governs speed at every point on every conic, elliptic through hyperbolic

The Tsiolkovsky rocket equation costs out every burn, with a two-stage form for cradle-and-ship staging

Hill-sphere SOI radii decide when you leave one body's gravity well and enter another's, with nested moon SOIs taking precedence

Gravity assists modeled as hyperbolic flybys with turn angle set by periapsis radius and excess velocity

Solar power falls off as 1/r² from the Sun; RTG output decays on the real Pu-238 half-life of 87.7 years
What you do

Plan and execute burns from an Apollo-style DSKY: local orbit changes, Hohmann transfers, rendezvous, circularization, interplanetary Lambert transfers, gravity assists, and full heliocentric multi-leg trajectories

Run cargo, passenger, resupply, and survey contracts across the solar system; build station reputation to unlock trusted and elite tiers, then chase the eight endgame megamissions

Land on planets, moons, and minor bodies; mine ore, ice, volatiles, and fissionables; deploy ISRU refineries and bioharvest plants to sustain operations past Jupiter

Buy and fly a fleet of six ship classes, from the bare Scout to the ion-driven Endurance; build staged propulsion cradles for missions your ship can't reach on its own tanks

Survive micrometeorite swarms in LEO, the belt, and Saturn's rings; solar flares that fry unshielded avionics; depleted batteries; and the slow decay of your RTGs over the years

Install upgrades — Whipple shields, panel shrouds, flare-hardened avionics, radioisotope generators — and salvage the wrecks of pilots who didn't
Features

Patched-conic orbital mechanics — no approximations, no autopilot

Apollo DSKY flight computer interface with 20+ programs

38-body solar system: planets, moons, asteroids, and Kuiper Belt objects

8 endgame megamissions with permanent career titles

6 ship classes with distinct role bonuses

Procedural SID/Amiga chiptune soundtrack

Runs fully offline — no network connection required