Harmful Interference

Harmful interference is generally understood to mean the external blocking or lessening of services provided by space systems, which can be accidental or intentional, and includes interference with any space services ranging from commercial services to critical safety-of-life applications. Article IX of the OST establishes that if a State believes that its activity or an activity of its nationals would cause “potentially harmful interference” with the activities of other States Parties, then it shall undertake “appropriate international consultations” before proceeding with the activity. Moreover, the OST gives a potentially affected State the opportunity to request consultations if it has reason to believe that another State’s activity could cause potentially harmful interference with its peaceful exploration and use of outer space. This consultations process is recognized as a prerequisite for the effective environmental protection of outer space. However, it has never been used and there is no guidance on what constitutes a consultation.

While the OST does not define the concept of harmful interference, the concept is defined in both No. 1.169 of the Radio Regulations and in No. 1003 of the ITU Constitution, as “interference which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs, or repeatedly interrupts a radiocommunication service operating in accordance with Radio Regulations”.