Progress 59 decay estimate

From: Ted Molczan via Seesat-l <>
Date: Sat, 2 May 2015 21:52:43 -0400
Using the numerical integrator in GMAT 2014a, I found that Cd=2.2 and A/m=0.00248 m^2/kg are sufficient to account for
the decay over the span of USSTRATCOM's TLEs of epoch 15118.86793256 and 15122.85272294. 

Allowing the propagation to continue until decay, results in impact (10 km altitude) on 2015 May 09 near 07:40 UTC. The
uncertainty is 30 h, based on the rule of thumb of 20 percent of the estimated time remaining to decay, measured from
the epoch of the latter of the two TLEs.

I converted the epoch 15118.86793256 TLE for propagation by GMAT using TLE Analyzer 2.12. I configured GMAT to use the
Dormand-Prince 78 numerical integrator, with the EGM-96 gravity model (degree 90, order 90), and the MSISE90 atmosphere
model. For the solar flux and geomagnetic index inputs required by MSISE, I used the daily mean values from Apr 29
through May 02 UTC. 

Ted Molczan

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Received on Sat May 02 2015 - 20:53:13 UTC

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