An orbital maneuver is a change from one orbit to another, accomplished by applying thrust. In deep space it is called deep-space maneuver (DSM).
Impulsive maneuvers
Usually thrust is produced in short bursts, since this is the most efficient, it minimizes gravity drag. These so-called impulsive maneuvers result in almost instantaneous velocity changes, referred to as delta-v (
). They are possible with high thrust-to-weight propulsion systems, e.g. chemical rockets.
Non-impulsive maneuvers
Applying a low thrust over longer periods of time is referred to as non-impulsive maneuvers (even though any thrust can be said to produce an amount of impulse). They are less efficient as energy can be lost due to gravity drag. However those maneuvers can be the only option when efficient but low thrust-to-weight propulsion systems are used (e.g. ion engines). They are not possible for a launch.
See also
