The reason that we can not leave the international matter of space debris unsettled is because we have launched a multipurpose satellite,Ari-rang No. 1, which is currently undetectable and lost.
  Considering the legal analysis of space debris problem based on space law and public international law, it is practically difficult to solve out just by defining the responsibility either of the actor or of the launching state. If the space debris problem is not only a matter of an individual state, it should be managed by the participation and cooperation of the global community. Therefore, we should discuss whether there is a legal basis to lead the states to participate in the space activity.
  Secondly, if the precautionary elimination of space debris is pertinent to overcome the limits of an ex post facto responsibility, we should focus on discussing whether there is a legal basis to charge with responsibility on the developed countries where they have technical capacities to remove the debris.
  Because the space orbit is entitled to all human beings, the resolution of space debris problem demands a common responsibility as a whole. Thus, in order to resolve the problem, we may expect not only on treaties but also on applicable legal principles. In addition, these principles must be recognized by the states to form as international law. Therefore, it is evident that "common heritage of mankind" and "sustainable development" provide an essential key to solve the problem.
  However, it is still obscure that whether there is a possibility to impose differential and burdensome responsibilities between developed countries, the dominant actors, and developing countries, the peripheral actors.
  Under the principle of sovereignty and equality, international law conceded with sacrifice by modifying the classical definition of "sovereignty" into a modern terminology in order to settle current international disputes. Particularly, the typical examples are not only international economic law, human rights law, environmental law, and the law of sea after the World War Ⅱ, but also space law.
  Although, it is difficult to enforce obligations and responsibilities on all states in a short term, the principle of "common but differentiated responsibility" is expected to provide an important clue to lead a participation and mutual agreement from both developed and developing countries.