Re: expert on reentries

Björn Gimle (b_gimle@algonet.se)
Mon, 9 Nov 1998 22:12:08 +0100

In a private mail, Manuel Borraz wrote:


>Dear Bjorn Gimle,
>
>I am searching for information about any possible reentry that could be
>linked to the following event.
>
>On 17 Dec. 1977, 7:45 pm (local) (that is, 18 Dec.1977, 1:45 GMT), an =
object
>crashed to the ground near Council Bluffs (Iowa, USA) (roughly 41=BA N =
/ 96=BA
>W). The presumed trajectory was SW to NE. A mass of molten metal =
(chiefly
>iron) was found on the site. A meteoritic origin was later discarded.
>

The NASA OIG SATellite SITuation report lists three decays on Dec.17-18,
and has the final(?) elsets, from which SkyMap gives:
 #  Center Date/Time  Duration  Status   Azm El NORAD Satellite Name
 1 77/12/18  2:32:16  0:06:57  Autotrack  53 17 10511 SL-4 R/B      =
Decayed: 1977/12/18
 2 77/12/18  1:44:06  0:07:18  Autopoint  64 12 10498 COSMOS 964    =
Decayed: 1977/12/17
 3 77/12/18  7:40:27  0:11:53  Autotrack 180 11 09866 DELTA 1 =
R/B(1)Decayed: 1977/12/17

The Delta rocket was in a 28 deg. orbit, so it was nowhere near Iowa.
The Cosmos was probably a photo-reconnaissance mission, de-orbited over
the Soviet Union, but it is possible a piece of debris landed elsewhere.
The SL-4 rocket elset was four days old at the time, and a small change
for an 11 % increase in drag is sufficient to make SatEvo predict
decay around 2 AM UT, bringing the predicted pass time back to 02:13 UT.

However, none of the two (?) candidates moved SW-NE, but NW-SE.

Bj=F6rn Gimle