Orbit Lab / Experiment 001

Find a satellite’s orbit

Adjust the sideways speed and starting height. Compare the predicted path with the result below.

EARTH / TWO-BODY MODELTIME COMPRESSED

Predicted trajectorySatellite

Initial conditions

Start with a preset, then change one condition.

Starting speed 1.00 × circularSlowerFasterStarting altitude 6,000 km500 km20,000 km

Predicted outcomeBound orbit

At circular speed, the ideal trajectory keeps the same distance from Earth's centre.

Initial speed— km/s

Orbital period—

Challenge 1 of 3

Find a circular orbit

Find a speed that keeps the distance from Earth almost constant.

Model limits: An idealised, spherical Earth and a small satellite. No air resistance, Moon, powered flight or uneven gravity. The path lies in one plane; time is compressed and the view zooms to fit. Earth texture: NASA Blue Marble. See the maths and sources →

01 / FALL

Surface impact

With a low enough starting speed, the predicted path intersects Earth's surface. The experiment stops at impact.

02 / ORBIT

Bound orbit

At circular speed, the satellite keeps a constant distance. Other suitable speeds produce elliptical orbits.

03 / ESCAPE

Escape trajectory

At or above the model's escape speed, the path no longer closes around Earth. Gravity still acts on the satellite.

Behind the experiment

Why sideways speed matters

Read the field note