Even if the present population of space debris poses only acceptable risks, it is necessary to follow its future development. The number of debris is steadily increasing and most probably it will continue to increase even if the generation of new debris is restricted. It may happen that the risks will become unacceptable in the future and that active removal of debris will become a necessity. Only few debris possess devices for de-orbiting. The majority of objects is inactive not only in the sense that they terminated their intended activities but also in the sense of having no capability for initiating or speeding up their own decay. Several methods have been proposed for removing inactive debris from orbit. All of them, however, require new technical developments. Also the cost of implementation is very high. The UN Committee realized the importance of theoretical research into methods for removal of inactive objects from Earth orbit on the Peaceful Uses of Outer Space. The Committee has recently encouraged such studies.