Introduction: Crew performance and group dynamic development in space has become an increasing focus due to the recent shift towards longer-duration human space missions to the Moon and Mars. Purpose: This study investigates the use of a Distinguishable Phase Model as a communication and training tool to help crews prepare for the pre- and intra-mission phases of a mission. Methods: The model first divides the mission duration into four distinct phases: acute, intermediate, long-duration, and final; where it can be used as a tool to identify (or suggest) when critical components such as mission mistakes, crew stress, motivation degradation, etc. may arise, which in turn can help reduce factors that could negatively affect group dynamic development. While the model will suggest when negative factors could present themselves during a mission, the analysis will also focus on positive aspects that contribute to positive group cohesion regardless of the frequency and location of mistakes during the mission. Furthermore, the study will suggest the addition of a fifth phase (after-effects of the mission), which will focus on crewmember interpersonal relationships. Results: From comparative studies the model was found to be a useful tool to identify when and where mistakes occurred during a mission and was reported by members of the MDRS crew to have played a positive role in group dynamic development. It was also discovered that mistakes at certain mission phase points could be linked to factors such as habitat/spacecraft problems and crewmember perceived stress, which are amenable to prevention in the early pre-mission phase of a mission.