What is priority inversion and how can it be solved?

Priority inversion occurs when high-priority task is blocked waiting for resource held by low-priority task, while medium-priority tasks run. Famous case: Mars Pathfinder. Solutions: Priority Inheritance Protocol (low task inherits high task's priority while holding shared resource), Priority Ceiling Protocol (task acquires ceiling priority of resource, preventing other tasks from preempting), Random boosting. Real-time systems must address this to meet deadlines.