While the world was celebrating 50 years of space activity, the United Nations' Committee on the Peaceful Uses of Outer Space (COPUOS) approved, during the 6-15 June 2007 session, a set of space debris mitigation guidelines, formally endorsed by the General Assembly on 14 November 2007 (A/RES/62/217, issued on 10 January 2008). Derived from the Space Debris Mitigation Guidelines, issued in 2002 by the Inter-Agency Space Debris Coordination Committee (IADC), the COPUOS guidelines consist of a set of seven high level mitigation principles covering space system design, launch, operation and disposal. This testifies to the growing relevance of space debris outside the relatively small number of engineers and scientists directly involved in research. The circumterrestrial space is, in fact, a very precious environment of great scientific, economic and strategic importance. All reasonable efforts must be made to preserve it for future generations and appropriate strategies should be devised, developed and implemented to minimize the impact of space debris on future space missions. Several significant results have been obtained in recent years, but a lot remains to be done in terms of enhanced observations, in situ measurements, environment and impact modeling, protection and implementation of affordable mitigation practices.