The Oberth Effect — Kerbal Space Program Walkthrough

Master the Oberth Effect in Kerbal Space Program by performing major burns at periapsis for maximum delta-V efficiency and reduced fuel needs.

The Oberth Effect states that performing a burn when you are moving fastest (at periapsis) is more efficient than burning at apoapsis. This is because the engine's thrust adds more kinetic energy when the vehicle is already moving at high speed. Always try to perform major burns (like orbital insertion or interplanetary transfers) at the lowest possible periapsis.

This effect is particularly noticeable for large transfer burns. By lowering your periapsis as much as possible before your main burn, you can significantly reduce the required delta-V, saving fuel and allowing for smaller, more efficient rockets.