Re: Discrepancy

From: Bob Christy via Seesat-l <>
Date: Wed, 7 Jul 2021 10:25:52 +0000
The 'problem' with the catalogue continues but the latest hiccup may hold a clue as to how the mis-numbered Designations occurred.

The Space-Track Catalogue page was revised July 6 at around 19:00 UTC to eliminate the 'phantom' that caused recent launch numbers to be incremented by one.

In the early hours of July 7, Space-Track issued its first element sets for five Cubesats released from Cygnus NG-15 on June 29 & June 30. They have Designations in the 1998-067 sequence belonging to the ISS, rather than Cygnus's 2021-013 range.

It raises the possibility that, on discovery, they were provisionally given their own launch number, accounting for either 2021-059 or 2021-060. The second of these was reserved for SpaceX Transporter 2. After a decision that the Cubesats were to be allocated to the ISS, subsequent launch numbers were revised downwards in the sequence. The first unclassified element sets for the Cubesats were then published.

1998-067xx Designations for the Cygnus Cubesats represent a break from precedent. Until now, Cubesat releases from Cygnus, and from Progress vehicles, have been designated using the launch number of the Cygnus or Progress.

We may see these Designations getting revised too.

If the latter, it still leaves Russell and other observers with the headache that caused him to ask the original question in this thread - how to report observations of items where a Designation may be subject to significant revision.

Finally - why the ISS Designations? Cataloguing of these objects was taking place during the melée of 80+ objects being released from Transporter 2. Cygnus re-entered on July 2. It could be that the only object in a similar orbit plane to the Cubesats when their turn came up for a firm allocation was ISS - hence the result that we see.

It should be pointed out that these are all administrative issues that affect the appearance of information and data in the public domain, they don't detract from the essential background job of tracking objects in orbit.

Robert Christy

> On 6 Jul 2021, at 21:07, Bob Christy <> wrote:
> The numbering published through Space-Track was incorrect (Option 1 in my original email).
> The Catalogue has been corrected. It now runs:
> 2021-057 - Soyuz MS-17
> 2021-058 - LauncherOne
> (2021-059 - Transporter 2) - yet to appear
> 2021-060 - OneWeb cluster
> 2021-061 - Jilin cluster
> 2021-062 - Fengyun 3E
> 2021-063 will be Tianlian 1-05 - launched today.
> Robert Christy

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Received on Wed Jul 07 2021 - 05:27:05 UTC

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