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Orbital Mechanics Sandbox
Two-body physics · Real units · Hand-rolled 2D and 3D renderers
A satellite orbits Earth and you fly it. Hover any thrust button to see the orbit you would end up with — the dashed orange line — before you commit to the burn.
2D
3D
- Altitude
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- Speed
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- Period
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Advanced
- Apoapsis
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- Periapsis
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- Eccentricity
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- Inclination
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- T to apoapsis
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- T to periapsis
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- Δv spent
- 0 m/s
- Energy
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Forces on spacecraft
Hover or hold a thrust button to preview the resulting orbit.
Thrust
Time
to see it properly.
Click the view for keys & zoom
Preset
Challengesclick to open
Rules of thumb
- Thrust changes the far side of your orbit, not where you are now.
- Speed up and the far side rises. Slow down and it drops.
- To raise the low point, burn at the high point — and the other way round.
- Burning where you're moving fastest, low down, gets you the most for your fuel.
- A tilt burn pivots your orbit about the line where it already crosses the equator. That line is fixed, so the two points on it are the only places a burn lands you in the plane you actually wanted.
- Tilting costs roughly 2 × your speed × sin(half the angle) — so it scales with how fast you're going. A 30° tilt down at 400 km costs about 4 km/s, more than it takes to fly to geostationary altitude in the first place. The same 30° up at geostationary costs about 1.6 km/s. Turn where you're slow.