Due Regard

Article IX of the OST establishes the obligation for States to conduct space operations with “due regard to the corresponding interests of all other States Parties”. This due regard obligation is an explicit limitation on the freedom to use and explore outer space guaranteed by article I of the OST. The concept of ‘due regard’ is not defined in the OST, and as such there is no uniform consensus regarding its meaning. However, under other sources of international law, such as the law of the sea —which States have expressed can be adapted and applied to outer space — ‘due regard‘ means that States are bound to refrain from any acts that might adversely affect the use of a domain by other stakeholders prior to and while conducting activities in that domain. Under the due regard principle, States are obligated to take the rights of other States into account when exercising their own rights. Related to the concept of ‘due regard’ is the duty of States to undertake international consultations before proceeding with any activity that might cause harmful interference with activities of other State parties. Under article IX of the OST, other States may also request consultations if they have reason “to believe that an activity or experiment planned by another State Party in outer space [...] would cause potentially harmful interference with activities in the peaceful exploration and use of outer space” either prior to or during the performance of the space activity