Reach the Moon
Choose your launch bearing, injection speed, flight-path angle, and lead the Moon's own motion — simulate a real Earth-Moon transfer and see if you reach the Moon's sphere of influence. Reaching it refunds your run.
Preview — sign up free to change the numbers yourself
What you can adjust
- Destination
- 0 – 0
- Mission mode
- 0 – 1
- Launch position
- 0 – 360 °
- Injection speed
- 6000 – 12000 m/s
- Flight-path angle
- -30 – 30 °
- Moon's starting position
- 0 – 360 °
Where you're aiming for. More destinations coming soon.
Direct launch: you control the injection burn yourself. Parking orbit: coast in a stable Earth orbit first, then an automatic burn sizes and fires itself toward the Moon — injection speed and flight-path angle below are ignored in this mode.
Bearing around Earth where you launch from, in degrees.
Your speed right after the trans-lunar injection burn. Real TLI burns reach close to Earth's escape speed (~10,931 m/s from this altitude) — too slow (below ~7,730 m/s) and you don't even hold orbit; a bit faster and you fall back to Earth well short of the Moon; too fast and you overshoot into an escape trajectory. Ignored in Parking orbit mission mode — the burn there is auto-sized for you.
Your burn direction relative to the local horizontal. 0 = straight prograde (the efficient default); tilt outward (+) or inward (-) to reshape the transfer path. Ignored in Parking orbit mission mode — every burn there is auto-prograde.
Where the Moon starts in its orbit, in degrees. The Moon keeps moving during your multi-day flight — you have to lead your shot.
About this simulation
What it shows
You plan a journey from Earth towards the Moon by choosing where you launch, how fast, and in which direction, and where the Moon starts. The path is drawn until you reach the Moon's region of influence or miss.
The key idea
Earth's gravity bends your path and the journey takes days, during which the Moon keeps moving. You have to aim ahead of where the Moon is now. Success means entering the region where the Moon's gravity dominates.
Try this
Keep Injection speed at 10,840 m/s and change Moon's starting position by a few degrees: the same launch can reach the Moon or miss it.
Simplified: Earth is held still, the Moon moves in a circle at its real distance, the rocket's own mass is ignored, and everything stays in one flat plane. Gravity from both bodies is real.