Utilization of natural resources in outer space has a potential to enhance our ability to explore and use outer space. It is generally acknowledged that without utilization of space resources human society can neither achieve the sustainable and robust presence on the Moon nor continue in the deep space exploration. However, lack of necessary legal framework and the consequent legal uncertainty surrounding legality and conditions under which space resources can be utilized represent a significant barrier for the exploration and use of outer space. In response, several countries (the United States of America, Luxembourg, and the United Arab Emirates) adopted national space laws including a chapter dedicated to space resource exploration and utilization/national space mining laws. However, outer space is an area recognized as res communis omnium. This article aims to analyse an inherent tension between the res communis omnium character of outer space and unilateral attempts to address the absence of international legal framework on the utilization of space resource. In particular, the paper examines whether national space mining laws can serve as a legal basis for space resource activities and consequently as a reliable source of legal certainty.