Operational lifetime is the period a satellite can perform its mission before a limiting factor—such as depleted propellant, hardware degradation, or power-system failure—prevents continued operation. It is an estimate, not a guarantee, and depends on the satellite’s design, environment, and use.
In cyber and space security, lifetime matters because evasive maneuvers can consume fuel and reduce the time a satellite remains usable. Other threats, including radiation or radio-frequency interference, may affect equipment or service, but their effects must be measured rather than assumed. Operators monitor fuel, component health, and orbit data to plan maneuvers and preserve mission capacity.