Design, prototyping and testing of an accelerometer for space missions

The growing demand for precise and accurate measurement systems in space missions has stimulated the development of innovative solutions in the field of accelerometers, capable of delivering high sensitivity and low noise over a wide frequency range. To achieve these requirements, an accelerometer based on a mass–spring system with a low natural frequency is needed, since both acceleration noise and sensitivity are related to the square of the natural frequency. This thesis addresses this challenge through the design, prototyping, and testing of an elastic suspension for a new accelerometer architecture intended for space applications, employing a heterodyne laser interferometry readout to detect the displacements of the proof mass. The research also encompasses the development of a dedicated test bench for the qualification of the accelerometer under microgravity conditions and the optimization of the data acquisition software. Based on the assessment of the technological framework and the defined system requirements—specifically, the need for the first natural frequency to be below 1 Hz—a prototype was developed, consisting of a beryllium–copper alloy proof mass and a titanium alloy spring manufactured using Powder Bed Fusion–Laser Beam, an additive manufacturing technique. The prototyping of the elastic suspension was complemented by laboratory experimental tests and the validation of finite element models. The test bench was equipped with an optical acquisition system controlled via LabVIEW software, together with video monitoring and additional sensors managed by microcontrollers. The analysis of the results obtained on the spring confirmed that the required specifications were satisfied.