This paper reports on the use and the evaluation of applying gaming aspects as a means to promote self-study and increase motivation to train for executing operations on human space flight missions that have a duration that exceeds the typical duration of low earth orbit missions. The gaming aspects that are evaluated include avatar representation, leaderboards, short ‘quest’ lessons, immediate rewarding, the notion of achievements, the structuring of training content using a skill-graph, and character development. These aspects are implemented in a prototype that integrates training execution, monitoring and evaluation. Subsequently, the prototype is used to evaluate the applicability and efficiency of gaming concepts for training. The evaluation is based on a structured walkthrough, where participants are guided and questioned while using the prototype in a predetermined way. In general, the results indicate that the use of gaming aspects have a positive impact on self-study and motivation. In particular the structuring of training content and the character development that is linked to it invites to train more. However, rich training material should be coupled tightly into the gaming aspects in order to achieve these results. This study provides an initial step into applying gaming aspects for astronaut training. More research should be done to further study the applicability of this approach.