Abstract:
This paper outlines the outcomes of a project seeking a low-cost solution for measuring the moments of inertia (MoI) of nanosatellites with masses up to 50 kg. A literature review was conducted,
followed by selection of the most appropriate solution type, a Trifilar Pendulum. Structural and
data acquisition design was then conducted and a suitable MoI measurement procedure derived.
The structure and two prototype platforms were commissioned and assembled along with a data
acquisition system, and MATLAB scripts were written for handling of the data. Calibration was
then carried out, using the prototype platforms, to test for verification and validation. Prototype
testing indicated that with several aluminium platforms for different weight ranges, robust, high
speed sensors, and a longer calibration routine probing the required range of oscillation-periods,
the end requirements are likely to be achieved. The first draft of a user manual was written, and
flaws in the design, remaining work, and suggestions for future improvements were outlined. The
prototype was used to measure the MoIs of various bolt assemblies and a thin aluminium disk, with
mass ranges from 0.0412 kg to 0.4214 kg and geometry ranges from 0.07 m x 0.0128 m x 0.10512
m to 0.105 m x 0.105 m x 0.10512 m. These MoI measurements were made with errors between
0.62% and 1.65%.