Distributed Interactive Simulation for Space Projects

What is distributed simulation and what are its benefits? Distributed Interactive Simulation (DIS) allows geographically separated simulators to work together, interacting in real-time, to provide predictions just like a single integrated simulator. The technology also allows real entities to be included in the simulation loop. Before this approach can be applied to space projects, however, it has to be established whether current simulation and communications technology can effectively support the critical requirements of space scenarios. It also needs to be demonstrated that this approach results in a cost-effective solution compared with the conventional approach of centralised simulators. The technical challenge The technical issues involved in implementing the distributed-simulation paradigm are related to interoperability and to the communications links. Interoperability requires the simulator to respect a certain architecture in order to be able to communicate with the outside world. As far as the communications links are concerned, the main difficulty is in coping with the timespan data requires to travel from the originating simulator to the receiving one (the so-called ‘latency’). In a real-time simulation, the distribution of the simulation models at remote sites introduces an error, because the data required by one model from another physically remote model needs a finite time to travel over the network. Assumptions about the current values of the remote model parameters therefore need to be made on the basis of earlier values (extrapolation using ‘deadreckoning algorithms’).