Designing data display system of spacesuit for extravehicular activities

The paper discusses issues involved in top-level design of a Data Display System (DDS) for a spacesuit used for extravehicular activities. It proposes external and internal criteria, and math statement of the problem of the DDS optimization. Based on the analysis of crew activities, DDS requirements were developed, which include some new requirements that had never been set before: Availability of interfaces between the DDS and onboard systems of the manned spacecraft; support for crew navigation on the outer surface of the space station; display of the required fragments from the onboard manuals; review of images obtained using a photographic or video camera; display of the current physiological parameters of the crew and provision of recommendations for optimizing his functional status. A concept for constructing a two-layer DDS is proposed. The first level is developed on the basis of highly reliable elements with a required degree of redundancy. An analogue of the first-level DDS is the existing spacesuit display equipment. The second-level DDS is built on the basis of commercial off-the-shelf components. It is proposed to develop the second-level DDS on the basis of a commercial tablet PC (possibly in conjunction with glasses or a projector). This approach is in line with the currently existing trend in Russian and foreign space engineering to build the onboard equipment on the basis of commercial off-the-shelf components. This speeds up the design process, but also imposes stricter requirements on the development and management of requirements for the systems, which are the basis for design, conduct of tests, operations management, upgrading. The proposed approach can also be used in the design of DDS for other complex systems.