Hohmann transfer orbit

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In orbital mechanics, a Hohmann transfer orbit moves a spacecraft between orbiting heights. It is the most fuel-efficient method to do so, because the spacecraft is not trying to escape the planet's gravity, using an elliptical orbit for the transfer.

A simulation of a Hohmann transfer orbit

A ship using this would have to apply two velocities, one to enter the elliptical orbit, and one to enter the second orbit.

Calculation[change | change source]

Assuming the mass of the spacecraft is much lower than that of the orbiting planet, the two velocities, and , can be solved for as:

where

  • is the mass of the planet,
  • and are the initial and final distances from the center of the planet.

Applications[change | change source]

  • Satellites can be moved into their proper height using a Hohmann transfer orbit.
  • A lunar transfer orbit (LTO) is used to reach the moon.
  • The Interplanetary Transport Network uses more than one body and requires lower velocity changes, and thus less fuel.