Transfer orbit

In orbital mechanics, a transfer orbit is an intermediate elliptical orbit that is used to move a spacecraft from one circular, or largely circular, orbit to another.

Part of a series on
Astrodynamics
Orbital mechanics
Orbital elements Apsis Argument of periapsis Eccentricity Inclination Mean anomaly Orbital nodes Semi-major axis True anomaly
Types of two-body orbits by eccentricity Circular orbit Elliptic orbit Transfer orbit (Hohmann transfer orbit Bi-elliptic transfer orbit) Parabolic orbit Hyperbolic orbit Radial orbit Decaying orbit
Equations Dynamical friction Escape velocity Kepler's equation Kepler's laws of planetary motion Orbital period Orbital velocity Surface gravity Specific orbital energy Vis-viva equation
Celestial mechanics
Gravitational influences Barycenter Hill sphere Perturbations Sphere of influence
N-body orbits Lagrangian points (Halo orbits) Lissajous orbits Lyapunov orbits
Engineering and efficiency
Preflight engineering Mass ratio Payload fraction Propellant mass fraction Tsiolkovsky rocket equation
Efficiency measures Gravity assist Oberth effect

There are several types of transfer orbits, which vary in their energy efficiency and speed of transfer. These include:

• Hohmann transfer orbit, an elliptical orbit used to transfer a spacecraft between two circular orbits of different altitudes in the same plane
• Bi-elliptic transfer, a slower method of transfer, but one that may be more efficient than a Hohmann transfer orbit
• Geostationary transfer orbit or geosynchronous transfer orbit is usually also a Hohmann transfer orbit
• Lunar transfer orbit is an orbit that touches Low Earth orbit and a lunar orbit.