1438. Erectable Space Structures: Automated Assembly and Utilities Installation

Paper

Abstract

This paper presents the results of a study of on-orbit assembly of tetrahedral truss platforms
erected of composite tapered, nestable columns. Several concepts for assembly were investigated
and a preferred concept, the gimbaled parallelogram assembler, was developed. This assembly machine
design provides fully automatic erection in either orbiter-attached or free-flying modes. Concepts
were also developed for STS packaging and transportation of construction materials and the assembler.
It is estimated that the automatic assembler would be capable of assembling a shuttle load of 20 m
columns in about 36 hours (free-flying mode). This estimate consists of eight hours for loading the
assembler and 28 hours of actual construction time. The resulting platform would have an area of 0.1 sq km.
An assessment of the effects of including non-structural systems (utilities) in the assembly process was
performed, and the effects on design and operation of the automated assembler evaluated. The installation
of candidate utilities was implemented using existing, state-of-the-art technology by add-on devices
or modifications to the baseline assembler design. Proper programming of utility installation allowed
compatible assembly sequences for a variety of platform sizes and shapes, with minimal impact on assembler
design and operation. The study results also showed that a postulated utilities network installation
on candidate platforms required little orbiter payload bay volume and thus imposed only a small reduction in
the size of the platform produced from a single STS load. However, the amount of total construction time
could be increased significantly, depending on the extent of the required utilities.