Performance Characterization of Space Communications and Navigation (SCaN) Network by Simulation

As future space exploration missions will involve larger number of spacecraft and more complex systems, theoretical analysis alone may have limitations on characterizing system performance and interactions among the systems. Simulation tools can be useful for system performance characterization through detailed modeling and simulation of the systems and its environment. To simulate space-based networks, we have developed the multi-mission advanced communications hybrid environment for test and evaluation (MACHETE) tool which captures the unique characteristics of space networking for performance assessment and end-to-end test evaluation. This tool contains orbital and planetary motion kinematics models, link engineering models, traffic load generation models and communication protocol models. This paper reports the simulation of the Orion (crew exploration vehicle) to the International Space Station (ISS) mission where Orion is launched by Ares into orbit on a 14-day mission to rendezvous with the ISS. Communications services for the mission are provided by the Space Communication and Navigation (SCaN) network infrastructure which includes the NASA Space Network (SN), Ground Network (GN) and NASA Integrated Services Network (NISN). The objectives of the simulation are to determine whether SCaN can meet the communications needs of the mission, to demonstrate the benefit of using QoS prioritization, and to evaluate network key parameters of interest such as delay and throughput.