The art and science of simulation, interactive entertainment and experiential learning have converged to provide new capabilities that have the potential to melt the boundaries between the training domains of virtual, live and constructive simulation and to create the next generation of Mixed Reality. Pulling from the foundational research of augmented reality, Mixed Reality has been able to tap the latest science and technology to spark the imagination and emotions. Mixed Reality may be the missing component needed to meet the challenge of transforming combined/joint training into the future. Once fully developed and implemented, Mixed Reality must create a training environment that combines the visceral nature of live training, with the dynamic and non-linear characteristics of virtual and constructive simulation.