Progress 59 decay estimate

From: Ted Molczan via Seesat-l <>
Date: Wed, 6 May 2015 08:37:29 -0400
Using the numerical integrator in GMAT 2014a, I found that Cd=2.2 and A/m=0.0030 m^2/kg are sufficient to account for
the decay over the span of USSTRATCOM's TLEs of epoch 15124.87998146 and 15125.98285285. 

Allowing the propagation to continue until decay, results in impact (10 km altitude) on 2015 May 08 near 08:26 UTC. The
uncertainty is 11 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. Taking into account the USAF's space weather forecast for this period, moves
the time of impact to 07:11 UTC, on the same day. 

I converted the epoch 15124.87998146 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

Ted Molczan

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Received on Wed May 06 2015 - 07:38:11 UTC

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