As part of the UK Space Agency National Space Technology Programme (NSTP-2) Fast Track call in 2015, the University of Bristol and Airbus Defence and Space (project leader) were awarded the project entitle "Robust Nonlinear Guidance and Control for Landing on Small Bodies" with the aim to investigate the application of advanced robust control techniques for the design and optimisation of Descent & Landing (D&L) trajectories on small planetary bodies.
TASC is responsible for the control development as well as the analysis and tuning activities for the guidance and control.
* Mr. Pedro Simplício (PhD student)
A renewed scientific interest has been growing in the exploration of small asteroids in addition to larger planetary bodies such as Mars, since their weaker gravitational field makes them more easily accessible. However, such exploratory missions are very challenging from an engineering perspective, particularly when
striving for optimal propellant consumption. This is mostly due to the perturbed and poorly known characteristics of small planetary bodies but also, as shown by the European Rosetta mission, to the long-time degradation of spacecraft subsystems.
In addition, close proximity operations, together with descent and landing (D&L) towards the surface of the targeted body, are some of the most critical phases for sample return missions. While common descent strategies involve an extended period of forced motion, either by translating to the surface from a close hovering station-keeping point or by starting the descent from a distant quasi-satellite orbit, significant fuel savings could be achieved by further exploiting the natural dynamics in the vicinity of the target.
In order to address the above challenges, it has been long recognised the need for robust D&L guidance and control algorithms.
The project will investigate innovative robust and nonlinear guidance and control techniques in the challenging frame of landing on small Solar System bodies.
By identifying a common structure in both state-of-practice and state-of-the-art command laws, it will provide a new common guidance and control framework for the descent and landing on small bodies. The industrial assessment component of the project aims at bringing these techniques up to TRL5, as defined by the ECSS European standards. Even though the example of a Phobos landing will be used as both a strategic and archetypal study case, a generic and modular implementation will enable their utilisation for other future exploration missions.
Description of Work
The NTSP-2 project is a one-year project (from April 2016), and is divided into 5 main work-packages:
The project will initiate a new collaboration between academia and the space industry, in line with the objectives of the National Space Technology Programme. Bringing together Airbus Defence and Space experience in industrial systems design and the University of Bristol leading-edge research capacities, it will reinforce the strategic positioning of Europe for exploration missions.
More specifically, it aims at increasing the Technology Readiness Level (TRL) of autonomous guidance and control technologies for descent and landing, which are key mission enabling technologies for identified ESA candidate missions including Phobos Sample Return.