Abstract: The technology relates to techniques for a dynamic threshold for a pressure or altitude trigger for a lighter than air vehicle. A method of operating a system of an LTA vehicle can include setting a dynamic threshold of a system to a first value based on one or both of a first measured pressure altitude and a first measured absolute pressure, receiving an indication that the LTA vehicle has increased its altitude, and setting the dynamic threshold of the system to a second value based on one or both of a second measured pressure altitude and a second measured absolute pressure. A flight termination system for an LTA vehicle can include mechanical actuation systems configured to be triggered based on dynamic thresholds. A method of terminating the flight of an LTA vehicle can include triggering the mechanical actuation systems based on dynamic thresholds.