Real physics space missions for iPhone
Real orbital mechanics. No rails. No cheating.
Pilot a spacecraft through 8 increasingly brutal missions — all powered by a live N-body gravity simulation running Velocity Verlet integration. Every burn matters. Fuel is finite. The universe does not care about your intentions.
Orbit Earth and fly through 5 gate checkpoints.
Learn every control — joystick, throttle, time warp, and trajectory prediction — before the stakes get real. Gates spiral outward so each one demands a slightly higher orbit, naturally teaching you to plan burns ahead of time.
Launch from Earth. Achieve a stable orbit around the Moon.
Classic orbital mechanics. Fight Earth’s gravity well, coast to the Moon, and execute a retro burn to get captured. The orbit detector tracks your altitude variance and cumulative angle swept — you need a full revolution to count.
Leave Earth orbit and dock with a moving space station.
The station doesn’t wait for you. Match its velocity, reduce relative speed below the lock threshold, and hold position while the docking ring fills. Approach too fast and you’ll bounce off.
Orbit all three Galilean moons — Io, Europa, and Ganymede.
Three separate stable orbits in one mission. Navigate the competing gravitational pulls of Jupiter’s massive moons in any order, raising and lowering your orbit with careful burns.
Intercept an inbound asteroid and push it off its collision course with Earth.
The asteroid is already moving. Dock with it by matching speed, then thrust to raise its periapsis above Earth’s atmosphere. Complete before impact — the clock is always running.
Skim the surface of the Sun. Fly through the perihelion gates.
The inner solar system: Sun, Mercury, Venus, Earth. Burn retrograde from your starting orbit beyond Earth to drop your periapsis all the way into the gate zone just above the Sun’s corona. Survive the fly-through. Repeat.
Thread through five plasma nebulas. Dock with the gold asteroid at the centre.
Deep space — no gravity assists, no safety net. Five massive plasma nebulas fill the arena; touching any one destroys your ship instantly. Navigate the narrow gaps in the right sequence to reach the gold asteroid at the origin, then slow down enough to dock.
Three suns pull each other into chaos. Make a close pass of each star.
A yellow dwarf, a tiny neutron star, and a swollen red giant — all pulling each other with full mutual N-body gravity. The system evolves chaotically. Predict their positions, time your approach, and fly through the gate of each star without getting flung into deep space.
| Control | Action |
|---|---|
| Joystick (bottom-left) | Set thrust direction |
| Throttle slider (bottom-right) | Set thrust magnitude (0–100%) |
| IGNITE / CUT | Toggle engine |
| ¼× ½× 1× 2× 4× | Time warp |
| ⏸ | Pause |
| Pinch | Zoom camera |
| Two-finger drag | Pan camera |
How do I control my spacecraft? Use the joystick to aim your thrust and the throttle slider to set power. Tap IGNITE to fire the engine. Your spacecraft follows real Newtonian physics — the universe provides no autopilot.
What is Time Warp? Time Warp speeds up or slows down the simulation (¼×, ½×, 1×, 2×, 4×) so you can wait for your orbit to carry you to the right position, or slow time to make a precise manoeuvre. Cut the warp before firing your engine — precision burns at high warp waste fuel.
What does the trajectory line show? The cyan dashed arc shows your predicted future path based on current velocity and gravity. It updates in real time as you thrust.
How do I complete Lunar Orbit? Escape Earth’s gravity well, coast to the Moon, then execute a retrograde burn to slow into lunar orbit. Hold a stable orbit for one full revolution — the ring in the HUD fills to completion.
How do I dock with a spacecraft or asteroid? Point retrograde relative to your target and reduce relative velocity. When you’re slow and close enough, the docking progress bar fills automatically.
How do I complete Jupiter Grand Tour? Achieve a stable orbit around Io, Europa, and Ganymede — in any order. Each moon requires its own dedicated capture burn.
How do I complete Perihelion? Burn retrograde from your starting orbit to drop your periapsis into the gate zone near the Sun. Flying through the gates counts a pass — you need three.
How do I survive Nebulon 5? The nebulas are instant death. Start from the right-hand entry corridor and navigate the 5-step maze slowly. Use low throttle and trajectory preview to plan each turn before you make it.
How do I complete Three Body Problem? Watch the three suns’ chaotic orbits and time your passes carefully. You need to fly within the gate radius of all three stars. The system is unpredictable — every run is different.
For bug reports, feedback, or questions:
📧 perihelion.support@gmail.com
Perihelion collects no personal data. Best times are stored only on your device and never transmitted. See the full Privacy Policy.
Perihelion is developed independently by Kyle Schaller.