For satellites in geosynchronous orbit, both the International Telecommunications Union (ITU) and United Nations (UN) recommends that GEO-satellites be designed such that they can, at end of life, remove themselves to a disposal orbit some above the GEO belt, and then passivate themselves by removing any internally stored energy.
The largest component of internally stored energy is generally unused propellant,[REF] although batteries are also important sources of stored energy that also require passivation [REF].