Stationkeeping

Stationkeeping is the set of methods and systems used to keep a vehicle, vessel, or platform at a fixed position and orientation over time, despite disturbances. It is applied in maritime operations, spaceflight, and other contexts requiring precise positioning.

In maritime contexts, stationkeeping is commonly achieved with dynamic positioning (DP) systems. A DP setup uses sensors such as GNSS, motion reference units, wind sensors, and gyrocompasses to estimate the vessel’s offset from a target point and direction. The system then commands thrusters and other propulsion devices to counteract currents, wind, and waves, maintaining a fixed location or prescribed track. DP enables drilling, survey work, and support operations without anchors, improving safety and efficiency in deep water.

In space, stationkeeping maintains a spacecraft near a designated orbital position. It requires periodic small propulsion maneuvers to counter perturbations from Earth’s gravity field, solar radiation pressure, drag (in low orbits), and other forces. The goal is to remain at a GEO slot, maintain phasing with another satellite, or hold a specific orbit. The frequency and size of burns depend on orbit, mission life, and propellant margins.

Key considerations include sensor accuracy, propulsion reliability, and propellant budgeting. Stationkeeping affects mission duration, safety, and operating cost. Advances in autonomous control, navigation sensors, and efficient thrusters continue to improve performance across domains.