🛰 Orbits and escape velocity

An orbit is a never-ending fall: a satellite falls toward the planet but moves sideways so fast that it keeps missing it.

• Low Earth orbit needs about 7.8 km/s; one lap takes about 90 minutes.
• To escape Earth for good you need 11.2 km/s; from the Moon only 2.4 km/s.
• At 35,786 km a satellite circles once a day and seems to hang still — geostationary orbit.