European Autonomous Flight Termination Systems Based in Smart Avionics

Operating a launcher is not exempt from risks. Even if we are talking about a reliable and tested system, the launchers need to operate in a very harsh environment. Thus, any issue can cause a failure and the loss of the control on the system. During the ascent phase, any failure implies risks to human lives since it would be a huge uncontrolled vehicle full of flammable fuel. Therefore, the launchers are tracked and monitored during the ascent phase, and in case any issue is detected, the launcher needs to immediately terminate (typically exploding).

A traditional flight termination architecture ensures independency from the vehicle functional chain using a radar network with human involvement in the decision-making process. This means: (i) considerable budget share for infrastructure and operations, (ii) limited flexibility (radar network needed), (iii) vehicle monitoring restricted to LOS conditions and (iv) delay inherent to communications and human reaction.

The autonomous flight termination systems (AFTS) determine the safety of the flight by processing different tracking inputs and comparing current estimated state to flight rules (also known as mission rules), defined by the user during flight missionization phase. By processing the mission rules directly on-board, the reaction time is reduced, and the telemetry downlink is no longer required.

Within Europe, there is no clear standard on the design nor operation of an AFTS. The critical part of this type of standards is related to managing the idiosyncrasy of the flight regulation in each country, making it difficult to have a common standard in Europe. The solution proposed is to have a highly configurable unit, in which the range safety officer could even include proprietary software for the termination logic, thus adapting to each specific local flight regulation without the need to perform any factory customization.

The paper describes the general problem and the proposed solution for a European Autonomous Flight Termination System highly configurable by the user, which make is suitable for a broad range of launchers and countries. Sener is developing an AFTU demonstrator in the frame of the RD EC Horizon Europe programme.