Physical assets by SHS in the framework of ISRU and ISFR paradigms for human space missions on the Moon

In this work a brief overview of the most important technologies for space exploration, with particular emphasis on the Moon missions, is presented. It is shown that the focus has been on the technologies to extract consumables (O2, H2O, N2) for human life-support replenishment. The fact that the exploitation of extraterrestrial resources to obtain the desired materials during each ongoing mission, which has been the subject of several investigations since the sixties of the last century, is discussed. The paradigms ISRU (In Situ Resources Utilization) and ISFR (In Situ Fabrication and Repair) are then introduced. In particular, one of the most important process for the production of oxygen, i.e. the reduction of ilmenite by hydrogen is analyzed. In addition, the current iteration of the roadmap which identifies two feasible pathways for human missions after ISS(International Space Station) is addressed. Next, the fabrication of Lunar physical assets is taken into account, while focusing particularly on those processes where combustion-like reactions are exploited. The main results recently obtained in the literature in this regards are also summarized. In particular, the choice of the reducing agent and the influence of the most important processing parameters (composition of the starting mixture, gas pressure level, and gravity conditions) are examined in a systematic manner.