Much of the world depends on GEO satellites for defense, communication, science, and weather monitoring. These expensive assets eventually fail or run out of propellant, but refueling and maintaining them can extend their lives, giving their users more value. Servicing can also help make space more sustainable because broken and drifting satellites take up valuable real estate in GEO and pose a risk to neighboring systems.
Once launched, satellites generally cannot be refueled or repaired. Satellites have lifetimes limited by the amount of propellant they can carry on board to maintain their orbits. A failure of a key system on a satellite can partially or totally disable the spacecraft, causing a disruption in service and potentially creating a hazard for other satellites.