China’s first space station, Tiangong-1, returned to earth on 1 April 2018 after more than six years in outer space. This was not isolated and some of the previous return of space objects are Cosmos 854 in 1978, Skylab in 1979, Delta II second stage in 1997, MIR Space Station in 2001, Italian BeppoSax in 2003, US-193 in 2008 and ESA’s GOCE in 2013. In light of these events and its inevitably increasing frequencies, it is necessary to reflect on the international law governing the re-entry of space objects.
In the current international legal framework, the state obligations cover the whole process of re-entry without obvious loopholes, preventative ex ante and responsible ex post. But the state practice is largely uneven and there are controversies and ambiguities over obligations to forewarn hazardous events and disclose information for facilitating damage control and cleanup operation; under what conditions can reentry objects be actively removed; and how to return the objects and compensate the damages. This requires adjustment and fine-tuning of some critical notions in the space treaties and other legal documents, particularly, how to apply victim-oriented and environment-friendly principles in space sector, the balance between launching states’ jurisdiction and control of space objects and the interest of other states, the definition and determination of damages and state responsibility for hazardous activities.