Inclined Orbit Operations
A cost-saving operational mode for aging geostationary satellites in which north–south station-keeping is discontinued, allowing the satellite's orbit to incline relative to the equatorial plane. Ground stations must track the satellite's apparent figure-eight motion (analemma).
Full Definition
Geostationary satellites normally consume significant propellant maintaining a near-zero orbital inclination via north–south station-keeping manoeuvres. When propellant runs low, operators may choose to discontinue north–south station-keeping, allowing the orbital inclination to increase over time (typically at roughly 0.75° per year). The satellite then traces a figure-eight or analemma pattern in the sky as seen from the ground. Ground stations serving inclined-orbit satellites must be equipped with tracking antennas capable of following this daily motion. Editors should hyphenate 'inclined-orbit' when used attributively ('inclined-orbit satellite', 'inclined-orbit operations') and note that it is a distinct phase of satellite life, not a failure mode.
Usage
Usage note: Hyphenate attributively: 'inclined-orbit satellite'. Do not equate with satellite failure; inclined orbit is a planned operational phase. The satellite remains functional for revenue-generating services.
In Context
- "The teleport upgraded its antenna control units to support inclined-orbit operations for the ageing fleet of legacy satellites." — Infrastructure Upgrade Proposal
- "During inclined-orbit operations, the daily peak inclination of 4.5° required continuous autotrack to maintain signal levels above threshold." — Operations Report