Lessons learned when developing a high performance attitude controlled platform to achieve microgravity for low-cost experiments

Available Attitude Control Systems are often targeted at orbital flights, and therefore manoeuvre slowly. As such, these solutions are suboptimal for sounding rocket experiments, as experiments such as those conducted on free falling units have restricted flight times. Furthermore, current attitude control systems are usually aimed at projects with extensive funding, and are therefore out of the budget range of low-cost experiments. Taking these constraints into account, the objective of project ASTER is to design and test a low-cost, fast-acting solution, to stabilise and orientate a free-falling platform, which is capable of providing microgravity conditions for experiments. The proposed design utilises three reaction wheels, controlled by a closed loop system, to stabilise the Free Falling Unit within seconds. The platform will be able to perform predefined slewing manoeuvres, which can be adapted to a wide range of applications. The free falling unit is a cube weighing around 3kg with a side length of 150 x 150 x 180 mm, with a recovery parachute system included. Designed to act as a system platform for free falling units, it will be able to accommodate future experiments, providing an easily adaptable payload bay with dimensions up to 56 x 91 x 77 mm. Furthermore, the system will be recovered after the experiment has been concluded and the results obtained will be published on an open source basis to ensure its future availability to other student and low budget research projects, thereby allowing further improvement, optimisation, and customisation. The experiment development began in September 2019 and is scheduled to fly on a sounding rocket in March 2023. Team ASTER wants to contribute to the student community by sharing the experiences and lessons learned during the project development, which is what will be focused upon in this paper and accompanying presentation.