RE: USA 186 recovered by Greg Roberts

From: Ted Molczan via Seesat-l <>
Date: Sat, 28 Nov 2015 15:23:21 -0500
Brad Young asked,

> What is the criteria for when something is recovered? I've always wondered about that –
> there doesn't seem to be any specific number of days since it was seen last, type of object
> (Other than it's classified of course), or method of recovery that defines a recovery.

We don't have formal criteria. Lately, I have used the terms re-discovery and recovery. The former is the result of an observer spotting an object as an UNID, that is subsequently identified by correlating against a catalogue of known orbits. The latter is the result of an active search for an object for which the last known orbit is believed to no longer be reliable.

Duration since last observation is not a useful criterion. Elements of an object subject to small perturbations may be valid for months. At the other extreme, an object with a high A/m, that is near decay may be sufficiently lost after one day to require a planar search. Likewise, after an manoeuvre.

Ted Molczan

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Received on Sat Nov 28 2015 - 14:24:03 UTC

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