The precautionary approach and challenges posed by mega-constellations

Abstract

The advent and continuing deployment of mega-constellations has brought new challenges, particularly increased risk of collision, proliferation of space debris, reduced numbers of launch windows and obstruction to astronomical observation. The precautionary approach, which is becoming part of customary international law, is instrumental in addressing these challenges. Although precautionary measures are incorporated in international treaties and soft law instruments regarding outer space, a full application of the precautionary approach is necessary to balance the need of innovation and the sustainable use of outer space. To this end, operators of mega-constellations must keep the approach in mind and comply with its substantive obligations once it is triggered, including suspension of activities, risk assessment, mitigation and prevention, and notification and information. The possibility of new deployment of mega-constellation being frozen at some point makes the equitable distribution of satellite orbits and radio frequencies a pressing issue.