Fly real astrodynamics from an Apollo-era DSKY. Plan Lambert transfers, mine asteroids, build a fleet, and survive a 38-body solar system where every trajectory is solved from Kepler's equation. No autopilot, no cheating.

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.<br><br>Every trajectory you fly is one a real spacecraft could fly. There is no &quot;go to planet&quot; button. The propagator never cheats on your behalf.<h2 class="bb_tag" >Real orbital mechanics, not an approximation</h2><br>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.<br><br><ul class="bb_ul"><li>Kepler's equation solved every tick with a Danby starter and Newton–Raphson iteration; the hyperbolic form handles escape and flyby trajectories<br></li><li>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<br></li><li>Hohmann transfers compute the phase angle and Δv for the cheapest two-impulse hop between circular orbits<br></li><li>The vis-viva equation governs speed at every point on every conic, elliptic through hyperbolic<br></li><li>The Tsiolkovsky rocket equation costs out every burn, with a two-stage form for cradle-and-ship staging<br></li><li>Hill-sphere SOI radii decide when you leave one body's gravity well and enter another's, with nested moon SOIs taking precedence<br></li><li>Gravity assists modeled as hyperbolic flybys with turn angle set by periapsis radius and excess velocity<br></li><li>Solar power falls off as 1/r² from the Sun; RTG output decays on the real Pu-238 half-life of 87.7 years</li></ul><h2 class="bb_tag" >What you do</h2><br><ul class="bb_ul"><li>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<br></li><li>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<br></li><li>Land on planets, moons, and minor bodies; mine ore, ice, volatiles, and fissionables; deploy ISRU refineries and bioharvest plants to sustain operations past Jupiter<br></li><li>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<br></li><li>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<br></li><li>Install upgrades — Whipple shields, panel shrouds, flare-hardened avionics, radioisotope generators — and salvage the wrecks of pilots who didn't</li></ul><h2 class="bb_tag" >Features</h2><br><ul class="bb_ul"><li>Patched-conic orbital mechanics — no approximations, no autopilot<br></li><li>Apollo DSKY flight computer interface with 20+ programs<br></li><li>38-body solar system: planets, moons, asteroids, and Kuiper Belt objects<br></li><li>8 endgame megamissions with permanent career titles<br></li><li>6 ship classes with distinct role bonuses<br></li><li>Procedural SID/Amiga chiptune soundtrack<br></li><li>Runs fully offline — no network connection required</li></ul>

Good Game Database

Patched Conic Achievements