Using the numerical integrator in GMAT 2014a, I found that Cd=2.2 and A/m=0.0037 m^2/kg are sufficient to account for the decay over the span of USSTRATCOM's TLEs of epoch 15126.77762021 and 15127.44781874. Allowing the propagation to continue until decay, results in impact (10 km altitude) on 2015 May 07 near 23:33 UTC. The uncertainty is 3 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. For both the calibration of A/m and propagation to impact, I used a rough average of observed and forecast space weather. I converted the epoch 15126.77762021 TLE for propagation by GMAT using TLE Analyzer 2.12. I configured GMAT to use its Dormand-Prince 78 numerical integrator, with the EGM-96 gravity model (degree 90, order 90), and the MSISE90 atmosphere model. Ted Molczan _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-lReceived on Thu May 07 2015 - 07:45:05 UTC
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