04 · Transfers

Parks

LEO, SSO, MEO, GEO, TLI — altitudes with jobs. GEO’s period matches a sidereal day. SSO precesses with the year so the light never changes.

In English

We name orbits by what we do there. LEO is close. SSO is LEO that keeps the same sunlight. MEO is navigation. GEO sits still in the sky. TLI is a throw at the Moon, not a round parking space.

Try this: Click LEO, GEO, TLI. Read period and the job line.
Keep this: Named orbits are altitudes (and tilts) with jobs.

Lab · where we actually park

Named orbits are just altitudes (and inclinations) with jobs. LEO is close and cheap to reach, expensive to stay if drag bites. GEO is one spot in the sky and a long climb.

Altitude: 400 km
Period: 92.4 min
Circular v: 7.67 km/s

ISS, Starlink, Earth observation

GEO altitude is the r where T equals one sidereal day (~23 h 56 m), about 35 786 km. SSO uses J2 precession: inclination near 98° so the node moves ~1°/day.

GTO is an ellipse with periapsis in LEO and apoapsis at GEO — a Hohmann left unfinished so the satellite can circularize and change plane with its own engine.