Calculate the speed required for a circular orbit at a given altitude.
Orbital velocity falls as altitude rises, so higher orbits are slower and take longer. Low Earth orbit requires about 7.7 km/s and completes roughly sixteen orbits a day. Because higher orbits are slower, a satellite cannot simply speed up to catch another in the same orbit — it must change altitude, which is the core counter-intuition of orbital mechanics.
Orbital Velocity
v = √(G M ÷ r), with r measured from the centre of the body
v = √(G M ÷ r), with r measured from the centre of the body Orbital velocity falls as altitude rises, so higher orbits are slower and take longer. Low Earth orbit requires about 7.7 km/s and completes roughly sixteen orbits a day.
Because higher orbits are slower, a satellite cannot simply speed up to catch another in the same orbit — it must change altitude, which is the core counter-intuition of orbital mechanics.
This calculator takes 3 inputs: Mass of the central body, Radius of the central body, Orbital altitude. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.