Week in Space Data, every Friday.
A comprehensive visual guide to orbital mechanics and the major orbit types used in spaceflight -- from low Earth orbit to interplanetary transfers.
Visual scale showing orbit altitudes relative to each other (Mars Transfer excluded for scale)
At-a-glance metrics for all orbit types
| Orbit | Altitude | Period | Velocity | Delta-v |
|---|---|---|---|---|
LEO | 160 - 2,000 km | ~90 minutes | ~7.8 km/s | ~9.4 km/s from surface |
MEO | 2,000 - 35,786 km | 2 - 24 hours | ~3.9 km/s | ~12.3 km/s from surface |
GEO | 35,786 km (exact) | 23 h 56 min (sidereal day) | ~3.07 km/s | ~14.0 km/s from surface |
HEO | 500 - 39,900 km (varies) | ~12 hours (Molniya) | Variable (0.9 - 10 km/s) | ~14.5 km/s from surface |
SSO | 600 - 800 km (typical) | ~96 - 100 minutes | ~7.5 km/s | ~9.5 km/s from surface |
PO | 200 - 1,000 km | ~87 - 105 minutes | ~7.5 km/s | ~9.5 km/s from surface |
GTO | 185 km perigee - 35,786 km apogee | ~10.5 hours | ~1.6 km/s at apogee, ~10.2 km/s at perigee | ~12.2 km/s from surface (to GTO), +1.8 km/s to circularize |
LTO | ~185 km to 384,400 km | ~4 - 6 days (transit) | ~10.9 km/s at TLI | ~3.1 km/s from LEO (trans-lunar injection) |
L1/L2 | ~1.5 million km from Earth | Halo orbit: ~6 months | ~0.2 km/s (station-keeping) | ~3.4 km/s from LEO |
MTO | ~1 AU to ~1.52 AU (Hohmann) | ~6 - 9 months (transit) | ~11.6 km/s departure | ~3.6 km/s from LEO (TMI) + ~2.1 km/s MOI |
GYO | ~36,100 km (300 km above GEO) | ~24.5 hours | ~3.05 km/s | ~11 m/s from GEO |
NRHO | ~3,000 - 70,000 km from Moon | ~6.5 days | ~0.1 - 1.4 km/s | ~0.8 km/s from low lunar orbit |
The change in velocity needed to perform a maneuver. It is the fundamental "currency" of spaceflight -- every orbit change, launch, and landing has a delta-v cost.
The time for one complete orbit. Governed by Kepler's third law: period squared is proportional to semi-major axis cubed. Higher orbits are slower.
The angle between the orbital plane and the equatorial plane. Zero degrees is equatorial; 90 degrees is polar. Sun-synchronous orbits typically have ~97-98 degree inclination.
How elongated an orbit is. Zero is a perfect circle; values approaching 1 are highly elliptical. Molniya orbits have eccentricities around 0.74.
The most fuel-efficient two-impulse maneuver to transfer between two circular orbits. It uses an ellipse tangent to both orbits, with burns at perigee and apogee.
Five gravitational equilibrium points in a two-body system where a small object can maintain a stable position relative to both large bodies. L1 and L2 are most useful for spacecraft.
Data sourced from NASA, ESA, and IAF publications. Altitude, velocity, and delta-v values are approximate and may vary depending on specific mission parameters, launch site latitude, and spacecraft mass. This guide is intended for educational purposes.