Parameter design and precision measurement of space cable-strut deployable articulated mast

A theoretical analysis model for a space cable-strut deployable articulated mast worked at its on-orbit state was developed by using Euler beam theory, which aimed to a working state that the mast was extended out the spacecraft and its load mass was supported by the mass tip. The natural frequency and the root bending strength of the mast when mast worked on-orbits were analyzed. The primary parameter design method of the mast were studied based on the natural frequency constraint and root moment constraint, then the relationships between the primary design parameters of the mast such as line density, mast radius, longeron section area and the natural frequency and the root bending moment were discussed through calculation examples. A prototype of space cable-strut deployable articulated mast was developed, and its bending stiffness and bending strength are 0.388 MN·m² and 562.12 N·m, respectively, which validates that the mast has very high bending stiffness and strength. Meanwhile, the repetitive deployable orientation precision of the mast prototype was measured on the ground. Results show that the mast prototype can offer higher repetitive precisions in 0.127, 0.645 and 0.588 mm for axis, horizontal and vertical directions, respectively.