GCAT: General Catalog of Artificial Space Objects

Jonathan C. McDowell


Analyst Objects

In the derived catalog 'currentcat' I have added about 700 objects with 'C' prefixes. These are debris objects tracked by the US Space Force which they have not identified with a specific launch.

Analyst Objects in the Space Force Catalog

The main, public US Space Force catalog has a running catalog number starting with 1 (Sputnik 1 rocket stage) and going to currently somewhat over 51000.

The criteria for a previously undetected debris object being added to the catalog are traditionally:

The Space Force also generates orbital solutions for objects which do not yet meet these criteria, but might later get added to the catalog. These are called `analyst objects' (the data will be studied by analysts for possible later identification). Historically these are assigned fake catalog numbers between 80000 and 90000 (and possibly between 70000 and 80000, although the orbital data for those has not generally been released). More recently, objects detected by the Space Fence have been given numbers starting at 270000.

A few datasets of the analyst object TLEs became public (possibly inadvertently) over the years, and then in 2020 a subset of analyst TLEs started being regularly released by 18SPCS on Space-Track.org.

To distinguish the analyst objects, I add them to my supplementary CSOCAT catalog (which also contains objects from other sources such as hobbyists). CSOCAT catalog numbers in the ranges 80000-89999 and 270000 upwards are reserved for US Space Force analyst object TLEs.

These objects fall in several categories:

Objects in the CurrentCat

Only the `persistent analyst objects' are really of interest, as real well-tracked objects which would be in the main catalog if they were associated with a known launch. As of Feb 2022 there are a little under 700 of these. This is just a few percent of the number of tracked debris objects in orbit, and a small number compared to the 17600 such objects reported to exist by 18SPCS.

All the analyst objects for which I have any data are included in the Complementary Catalog `csocat'. Use that data with care, since they include objects which are not necessarily real, and ones which have been reassigned with new numbers elsewhere.

The 700 robust `persistent analyst objects' are now included at the end of the derived product `currentcat' so that they can be used in statistical studies.

Tentative Identifications of Analyst Objects

I have attempted to identify these analyst objects.

In future I hope to take a more rigorous approach by creating new designations for specific debris clouds.