Design of an exact 3U-size CubeSat mockup for air-bearing based testing

CubeSats have emerged as a cost-effective and scalable solution for various space missions, ranging from Earth observation to deep-space exploration. Testing their dynamic behavior in simulated microgravity environments is crucial for design optimization and mission success, particularly for robotics-based satellite on-orbit servicing operations. This research presents the development of an exact-size 3U CubeSat platform designed for air-bearing-based testing to simulate free-floating motion in a 3 Degrees of Freedom (DOF) system. The platform analyzes the interaction dynamics between the CubeSat and a robotic arm to mimic satellite capture. The uniqueness of the test platform is its exact dimensions as a real 3U CubeSat which is difficult to achieve due to the available sizes of a pressure-gas tank and air bearings. The tested CubeSat's Exact size and mass are needed to test and investigate space robotic grasping and servicing. The design and prototyping of the CubeSat platform employ Fluid Deposition Manufacturing (FDM), a form of additive manufacturing, which was performed with a Bambu Labs X1 Carbon 3D printer. This method ensures compliance with the CubeSat form factor. This allows the platform to have the same visual appearance at a low cost and weight, enabling the use of visual feedback and low-power robotic arms. The rapid prototyping enabled by FDM also facilitates quick troubleshooting and iterative design improvements. The modularity offered by FDM allows seamless integration of pneumatic and electrical subsystems. To replicate the frictionless motion observed in space, a pneumatically powered air-bearing system is incorporated into the platform. This system creates a microgravity-like environment supported by air cushions generated by the bearings, allowing the CubeSat to float on a polished granite surface with minimal resistance, thus enabling accurate simulation of satellite dynamics. While space is a 6 DOF environment, the 3 DOF planar system allows for nearly frictionless translational and rotational motions on the ground. This allows for the precise observation of the dynamic interaction between the CubeSat and robotic arms. The system integrates an Arduino ESP32 microcontroller with an IMU-6050 sensor and wireless communication capabilities via Wi-Fi. These components facilitate real-time monitoring of the CubeSat's position, velocity, and acceleration. The data collected is transmitted and synchronized with Google Firebase, ensuring a reliable and continuous data stream for analysis. Additionally, a VICON Motion Capture system is deployed for external data verification, providing a high-precision reference for validating the CubeSat's motion. This research demonstrates the potential of combining additive manufacturing, air-bearing systems, and advanced electronics for making an air-bearing-based CubeSat mockup of the same size and mass. The platform provides a reliable means for testing the robotic grasping of a CubeSat, offering accurate insights into the dynamics of robotic interactions and the CubeSat's response under microgravity-like conditions. The results contribute to advancing CubeSat development and testing methodologies, paving the way for enhanced mission reliability in future satellite servicing and on-orbit operations.