Expanding the amount of manned space flights requires a strong legal basis devoted ecological promotion of life support. Such field of legal regulation is branched and has some differentiations from one space-faring nation to another that is why it needs to be explored to implement it in the space legislation of Ukraine. Thus, the aim of this article is to observe all stages of life support of manned space missions according to legislation of main actors in such field of space market, i. e. Russian Federation, Republic of Kazakhstan, USA and ESA for taking into account while such a legal base is being developed in Ukraine.

     To fulfill the aim of this study the statements about life support according to five UN treaties on outer space, International Space Station Intergovernmental Agreement, national decrees, technical regalements, handbooks etc. were used. The research was conducted using methods of analysis, synthesis, comparison, structuring etc.

     As a result of study all the legal regulation of life support during space missions was structured: firstly, according to subject of regulation on requirements for people (medical, sanitary and other) and requirements imposed on the environment in the conditions of the space environment factors (weightlessness, radiation, lighting, etc.); secondly, according to stages of space missions on preparing to, execution of and rehabilitation after manned space mission. Common and distinctive features of such requirements pursuant to environment legislation of Russian Federation, Republic of Kazakhstan, USA and ESA were identified.

     Thereby, the following directions of Ukrainian legislation development in the analyzed sphere were outlined: 1) medical, physical, psychological etc. selection criteria for the acquisition of the status of astronauts; 2) requirements for living conditions and readiness to complete the tasks of space missions; 3) system of rehabilitation procedures after manned space mission execution.