Re: Mir debris

Rainer Kracht (0412188960-0001@t-online.de)
Sat, 28 Oct 95 19:27 +0100 

>Date: Fri, 27 Oct 1995 19:52:29 +0100 (BST)
>From: Russell Eberst <R.Eberst@roe.ac.uk>
>Subject: Mir debris

>Has anyone considered the difficulties that might arise to the next
>Atlantis-Mir link-up mission due in November, caused by at least seven
>fair sized pieces of debris emanating from Mir? These will be scattered
>almost all round the orbit and must pose some sort of impact threat to 
>Atlantis as it chases after Mir. The closing velocity will be small, so
>it won't be as bad as a head-on approach, but dodging these chunks must
>pose a fairly hazardous task for the pilot of Atlantis.
>Any comments?
>best wishes  Russell

There are 13 catalogued Mir fragments in orbit:

1986-17JD  23557  1995 Oct 27.1  359 x 367 km
     17JE  23558           27.1  381 x 391      (GFZ-1)
     17JF  23559           27.1  358 x 365
     17JH  23566           27.2  373 x 377
     17JK  23662           27.2  366 x 373
     17JL  23689           27.1  392 x 397
     17JM  23690           27.1  393 x 398
     17JN  23691           27.2  391 x 401
     17JP  23692           27.2  392 x 400
     17JQ  23693           27.2  393 x 400
     17JR  23694           27.2  393 x 402
     17JS  23695           27.2  393 x 403
     17JT  23698           26.0  389 x 392

Identifications of fragments:

Pierre Neirinck 1995 Oct 24 (Mir approx. 18:38 UTC)
     mm:ss
Mir +01:05  (JL)  mag 7.8 to invis. fp=2.5s
    +02:05  (JM)  mag 7.5 to invis. fp=4s?
    +02:32  (JN)  mag 7
    +02:40  (??)  mag 7?
    +02:57  (JP)  mag 7?
    +03:20  (JQ)  mag 6.5 to 8

Rainer Kracht with 10x50 on 1995 Oct 25
Mir & Fragments crossing a line from 51 Peg to SAO 108240:

17:44:22.16 UTC  Mir
17:45:32.42      +01:10.26 Frag 1 (JL) bright max mag 5.5
17:46:56.05      +02:33.89 Frag 2 (JM)
17:47:27.81      +03:05.65 Frag 3 (JN)
17:47:35.21      +03:13.05 Frag 4 (??) rapid flasher (fp=1s?)
17:47:54.46      +03:32.30 Frag 5 (JP) mag 6 steady
17:48:24.13      +04:01.97 Frag 6 (JQ) rapid flasher (fp=1s?)
17:50:34.91      +06:12.75 Frag 7 (JR) mag 6 steady

The object 7 to 8 seconds behind 86-17JN is not (yet?) catalogued!
It was seen by Pierre Neirinck on Oct 25 7.5 seconds behind 86-17JN.

I think, the impact threat is very small for known fragments, but it is 
rather incalculable for unknown fragments.

Rainer Kracht
0412188960-0001@t-online.de