Proceedings of the Workshop - United Nations Office for Outer ...

MAINTAINING THE SPACE ENVIRONMENT 199considered, besides the IADC, also by the InternationalAcademy o f Astronautics, IAA, representing thescientific community. The Report will be furtherconsidered by the Committee on the Peaceful Uses ofOuter Space, COPUOS. That committee will decidewhat further steps should be taken in dealing with theproblem o f space debris.The Report concludes2: "Space objects withdiameters larger than 10 cm in LEO and larger than1 m in GEO can be observed and tracked. More than8,500 catalogued objects are in Earth orbit. Thenumber o f in-orbit catalogued objects has beenincreasing at a relatively linear rate fo r the pastseveral decades. ... The trends and tendenciespredicted fo r the future orbital debris environmentare qualitatively in agreement ... The limitation o fmission-related debris and the prevention o faccidental explosions have been found effective andhave already been introduced to some extent. Also,the transfer o f GEO spacecraft into disposal orbits atthe end o f their active life is already customarypractice. ... For some satellites on long lifetime LEOorbits, a transfer to shorter lifetime orbits is plannedat the end o f their active life. Such procedures, ingeneral, could be most effective. ... Since most o f themitigation measures introduce some burden tomissions, it would be beneficial i f the same mitigationprocedures are considered globally. ”“In most cases, man-made space debris todayposes little risk to the successful operations o fapproximately 600 active spacecraft now in Earthorbit. However, the known and assessed population o fdebris is growing, and the probabilities o f potentiallydamaging collisions will consequently increase.Because o f the difficulty o f improving the spaceenvironment with existing technologies, theimplementation o f some debris mitigation measurestoday is a prudent step towards preserving space fo rfuture generations .... ”Questions arising from the growing number ofsatellites in orbit have been also considered by theFifth International Space Cooperation Workshop“Solving Global Problems”, organized by theAmerican Institute of Aeronautics and Astronautics,AIAA, was held at Bermuda, 11-15 April 19993. Theworkshop adopted several recommendations whichhave been presented recently to the Technical Forum.This session can either express its support to some ofthe recommendations or it can formulate its ownrecommendations. For the convenience o f this session,selected recommendations o f the AIAA workshopfollow:1. On the work of the COPUOS done withassistance o f the IADC and the IAA:"The Workshop participants strongly supportwork being done by the UN, the IADC, the IAA, andothers to develop guidelines designed to minimize thecreation o f new debris objects. ”“The Workshop recommends that existing andfu ture debris minimization guidelines be applieduniformly and consistently by the entire internationalspace faring community. In addition, governmentlicensing agencies are encouraged to promote suchcompliance among the space community in theirrespective countries. ”“In addition to minimizing the creation o f newdebris, the problem o f on-orbit debris must beaddressed Mitigation o f debris on orbit can beaddressed in at least two ways. First, by moving largedebris, such as satellites at the end o f operationallifetime, out o f the way o f active satellite orbits andsecond, by the active removal o f visible, butuntracked smaller debris. Some aerospace companiesare not including de-orbit capabilities on theirspacecraft, and hence these spacecraft will contributeto the problems o f orbital congestion and debris wellpast their operational lifetimes. ”2. On de-orbiting of spacecraft:“Governments and the commercial sector areencouraged to promote the application o f technical2 For a verbatim version and for details, the reader is referredto the original document.3 For details and justification see the Report on the workshoppublished by the AIAA and presented in the Technical Forumon 20 July 1999.