Updated: Oct 17, 2022
The UK Space Agency sought to understand the methods to quantify the “limits of useful mission” and the permitted deviation from a nominal trajectory as a function of time, velocity or other parameters such that the primary mission objective can still be at least partially fulfilled.
To support this, we conducted a study on how a “useful” versus a “non-useful” mission could be described. For example, data on which orbits were obtained where a mission was allowed to continue and not terminated on safety grounds, against the intended orbit.
To achieve this UKLSL initially conducted a detailed review of historical launch failures identifying scenarios where the flight was terminated based on the vehicle exceeding pre-defined parameters and where a flight of the vehicle was allowed to continue but deviated from its original mission parameters.
Then UKLSL evaluated the approaches/methodologies to define the flight safety limits and if possible, establish flight abort rules. Thus, the key mission parameters that can be used to characterise the limits of a useful mission are understood.

Keywords: Flight Safety, Vehicle, mission.