A smooth campaign for team COCO
In brief
Five students from the University of Southampton, UK, successfully conducted their experiment at ESA ESTEC’s Orbital Robotics Lab in the Netherlands. This was the first campaign of the Experiments Programme to be conducted at the ORL facility, where Europe’s flattest floor simulates a 2-D microgravity environment. Team COCO tested out an innovative system to manoeuvre satellites.
In-depth
Satellites are generally equipped with at least 8 thrusters oriented differently, allowing to control the movement of the satellite in all directions of space. Team COCO designed a AOCS (Attitude and Orbit Control System) with only two thrusters, that can be rotated and therefore fire in any direction. Reducing the quantity of thrusters saves on mass, volume and costs. This control system can be especially useful for space missions where quick movement of the satellite is needed, for example debris removal and docking manoeuvres.
Project COCO was selected in February 2024 to be part of the ESA Academy Experiments Programme and test their AOCS design in the Orbital Robotics Lab, at ESA ESTEC in the Netherlands. The five dedicated students developed their project on a short timeline and efficiently performed the design, assembly and testing of their experiment to be ready in time for the campaign, which took place from July 1st to July 12, 2024.
The first day of the campaign was already busy as the team had to integrate their hardware on MANTIS. MANTIS is a platform that floats on the ORL’s flat floor thanks to air bearings. Its frictionless motion provides microgravity conditions in three degrees of freedom (2D translation and 1D rotation) allowing to test satellite control systems such as COCO’s.
After integration, students performed component and system tests and prepared the environment by positioning the motion tracking cameras. During the following days of the campaign, activities included the calibration of the mechanical system and completion of the impulse characterization.
The students also had to investigate a leak issue with the pressure regulator and an anomaly with the algorithm. These issues were rapidly solved, and team COCO tested the four different Attitude and Orbit Control strategies they had planned: orbit control (movement in the x direction), attitude control (rotation), coupled movement (movement in x and y direction) and rendezvous (following a specific trajectory).
Each strategy was repeated 3 to 5 times to ensure the accuracy of results. Every day before operations, the very uniform floor of the laboratory had to be carefully cleaned, and the cameras had to be calibrated. After completing their own procedures, the team tested the winning algorithm of the “AOCS Challenge”, a competition created by COCO to offer to other motivated students the opportunity to try out their control algorithm in the unique ESA facility.
On day 9, the team challenged their system by mounting it on the ORL’s REACSA platform, which is much bigger than the MANTIS platform and therefore simulates better the inertia of a real satellite. COCO’s AOCS was able to control the trajectory of REACSA, concluding this fruitful campaign with another successful test.
On the final day, team COCO disassembled their experiment and packed all components. The five students travelled back to their home university where they will process the data and prepare scientific publications.