Nothing hides in space
A hard-science simulation of satellites, sensors and signals in Earth orbit. Every orbit, signal and sighting is computed from published physics.
One engine. Two ways in.
The physics of operating in space, run as a simulation you can read, test and play. Nothing is scripted: what you see is what the models say.
Computed, not scripted. Filmed in the game.
Every move is solved, not animated: Lambert's problem under the Earth's flattened gravity, the Sun and the Moon. The satellites start on their real orbits, and fuel trades against time.
Lambert transfers · J2, Sun and Moon · SGP4 from real element sets
A telescope sees a satellite only by the sunlight it reflects or the heat it gives off, worked out as signal-to-noise for every look. In the Earth's shadow it sees nothing.
Planck's law in band · Real sunlight and shadow
Hear the inspector's reports to its ground stations, fix them by direction finding, and identify each emitter by what its signal measures.
Friis link budgets · Direction finding · Modulation
Real ground radars see the inspector only on their passes; your own telescope holds it in between. Every track carries its uncertainty. And you win by being there: park close and it gives way, push too hard and tension climbs.
Kalman tracking · Real radar sites · Escalation, not shooting
Before you move, see when you will be seen: every sensor's look at you over the coming orbit, in sunlight and in shadow.
Every sensor, every look, computed ahead
Each platform is built from its equipment: dish sizes, power, thrust. Performance is computed from them, and every value cites its source or says it is a design value. The satellites are real, with their public specs.
Specs in, performance out · Every number sourced
The engine under the game. Free and open source.
godot --headless --path core/godot --script res://cli/run.gd -- --scenario= --hours=24Read up before you launch.
Both print cleanly, or read them on screen.
For playersThe platforms and equipment, the console, every control, and a walkthrough.
For the curiousThe engine under the game: every model, the sources it rests on, the checks that hold it to them, and how to use it as an open-source tool.
Found something wrong? Tell us.
Needs a free GitHub account. Reports are always welcome; code changes (pull requests) are not accepted. See open issues.
Free, no account, no install. Needs a desktop browser with WebGL 2, a keyboard and a mouse, and a 130 MB download on first load. Saves stay in your browser.