The Space Liner Federation – Distributed Space Vehicle Simulation Based on Loose Coupling

This paper describes a Web Live, Virtual, Constructive server approach that provides compliancy to the future High Level Architecture distributed simulation standard called "HLA 4", currently in the final balloting process at IEEE but not yet released. It represents a sustainable, alternative approach to already start with, being HLA 4 compliant as soon as this new standard will be released. The communication between loosely coupled web simulation modules and the run-time infrastructure of the future HLA standard is realized by service bridging from the Web Live, Virtual, Constructive protocol over WebSockets. This will enhance interoperability and re-use potential, because web simulation module developers do not have to cope with the specifics of HLA and can use the web standards they are experienced with. Although developed in a scripting language, an own server software development covers this bridging task. Its performance results from the use of a set of extension packages, providing different bindings for deeper processing needs on pre-compiled level. First use case results with DLR’s advanced concept for a suborbital, hypersonic, winged passenger transport vehicle called SpaceLiner show a real-time performance of an update rate of 50 Hz with 10 involved, distributed sub system modules. The use case implementation represents space vehicle specifics by extensions to the Space Reference Federation Object Model, a further domain specific standardization on federation object model level. Established a-priori interoperability will allow the independent development of the federation’s federates with a realistic inevitability that these parts of the distributed simulation will be able to smoothly interoperate. A position to future space / air traffic integration simulations is given and discussed. The paper concludes with an outlook on fusing possibilities with the air traffic management domain specific federation object model standard for future space / air traffic integration simulations.