Simplicio, Pedro (University of Bristol), Marcos, Andres (University of Bristol), Bennani, Samir (ESA/ESTEC (TEC-ECN))

A Reusable Launcher Benchmark with Advanced Recovery Guidance

Scheduled for presentation during the Regular Session "Spacecraft dynamics and control 1" (WeM3), Wednesday, April 3, 2019, 12:00−12:30, BL281.2

5th CEAS Conference on Guidance, Navigation and Control, April 3-5, 2019, Milano, Italy

This information is tentative and subject to change. Compiled on April 19, 2024

Abstract

The current interest on launcher reusability has led to several mission optimisation studies aiming to maximise payload while meeting tight aerothermal constraints. However, in this article it is shown that further benefits can be achieved by jointly addressing the tasks of vehicle dimensioning and guidance and control design. To enable this approach, a thorough understanding of reusable flight mechanics and of its fundamental guidance and control interactions is necessary. This can only be accomplished by using a benchmark specifically accounting for these couplings. This article presents such a benchmark, which is capable of simulating the launch and recovery of a vertical take-off and landing booster used as a first stage of a lightweight, non-winged vehicle, steered via thrust vector control, fins and cold gas thrusters. In addition, and based on the joint dimensioning/design assessment and developed benchmark, a guidance algorithm for retro-propulsive entry, descent and pinpoint landing based on successive convex optimisation is proposed. Comparable algorithms exist in the literature, but they tend to focus on maximising either computational efficiency (typically disregarding aerodynamic deceleration) or trajectory optimality (employing multiple convex approximations). Moreover, they are targeted to low-altitude and low-velocity flight, which is not representative of launchers. The proposed algorithm intends to provide a middle ground between efficiency and optimality that is specifically tailored to the extended flight envelope encountered by reusable launchers, and is therefore termed DESCENDO (Descending over Extended Envelopes using Successive Convexification-based Optimisation). Its effectiveness is verified in a closed-loop fashion using complete recovery scenarios included in the reusable launcher benchmark.