Beginning in 1962, in accordance with paragraph 1 of Resolution 1721B (XVI) of the United Nations, States launching objects into orbit or beyond began to register those objects with the United Nations. This registration takes the form of two series of documents, A/AC.105/INF and ST/SG/SER.E. Each individual document contains information supplied by a single member state on one or more space objects; the information supplied varies from document to document, but usually includes a designation for the satellite, the date of launching, and some orbital information.
In 1994 I attempted, for the first time, to organize the information present in the Registry in a coherent and uniform way for the use of scholars studying the history of space exploration. This product consists of a critically edited edition of the Registry, with references back to the original documents. This edition was prepared privately and is not connected with or sanctioned by the United Nations in any way.
The creation of the OOSA web site in the late 1990s and its improvement in the early years of the new millenium superseded some of the original goals of this version of the registry, but as far as I am aware the editorial comments in this list remain the only source of independent analysis of mistakes in the supplied data. I have therefore continued to update this version of the Registry. The original version of this description is archived in the file `old.html'.
Table 1, the list of space objects ordered by international designation, is not intended as an accurate and complete listing of all satellites, but rather as an accurate reflection of the contents of the UN documents. UN member states do not always provide the correct information. Readers looking for such comprehensive lists, some of which may include information from independent (non-governmental) analysts, should consult the Royal Aircraft Establishment Table of Earth Satellites (and its successor, Phillip Clark's Worldwide Satellite Launches), the TRW Space Log, the NASA Satellite Situation Report, or electronic listings.
In general, the only external information used in the compilation of this edition of the Registry has been the additions (in square parentheses ) of names of satellites not given in the registry, and the inclusion of objects not registered with the United Nations. For the period prior to 1994, the information has been taken from the COSPAR Bulletin, produced by the international organization COSPAR (Committee on Space Research), thus ensuring that the information provided comes from official international bodies (for more recent missing satellite names, I have used the name used in public statements by the launching state). It is hoped that the extra information will make the Registry easier to use. (It should be noted that prior to 2002 the United States, unlike the other member states contributing to the registry, never provided satellite names in its UN registration documents). A small amount of external information has been used to correct obvious errors or misstatements in the registration documents; this information is included by means of a series of editorial notes.
The United States, unlike most other states, provides information on non-functional objects (rocket stages, debris objects, etc.) in its registrations. I do not maintain this data in the registry For pre-2002 data, a separate list of United States (and some other) non-functional objects was compiled and can be found in Sections B and C described in the old introduction. The contents of the tables for each section are described in the Key, and the numbered notes to the table are in the Notes document.
One interesting aspect of the UN Registry is that it provides an independent source of orbital information for satellites. Most public orbital information comes from the United States Strategic Command, which releases Two Line Element (TLE) orbital data from its Satellite Catalog (SATCAT) for all satellites except classified US military ones. The Satellite Situation Report, the RAE Tables (for the most part), and the TLEs distributed by NASA-GSFC and by T.S. Kelso are all derived from the unclassified subset of the Space Command TLEs. A parallel catalog to SATCAT is maintained by the VKS (Russian Space Forces) but this is not yet available to outside users. A third source of data is provided by experts such as Mike McCants and Ted Molczan who collates observations by amateur satellite observers; this supplements the TLEs with orbits for some classified satellites not otherwise available. The UN registry, as required by UN Resolution, includes orbital information for even the US classified satellites. This orbital information is supplied by the US government and is presumably derived from the classified TLEs. However, it should be noted that in recent years the information supplied for such satellites has frequently been incorrect or misleading. The orbital data provided by the USSR, and more recently the Russian Federation, seems to be based on the VKS data and is therefore independent of the US TLEs. While the UN orbital information includes only 3 of the 6 classical orbital elements for each satellite, it is still the largest source of orbital data independent of the public TLEs, and for this reason it seemed worthwhile to make it more generally available.
Jonathan McDowell; Somerville, MA; Oct, 1994. and May, 2009.