Staged deployment analysis of a three-panel solar array

Replacing a constant 0.55 N·m damper with a 12.5 N·m·s/rad rate law cuts peak member bending from 203.5 to 10.9 N·m and latch arrival from 147 to 30.1 deg/s. The modelling choice that looks conservative in the margin budget oversizes the structure by a factor of twenty, and reverses which sequence is worst.

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NASA-STD-5017 torque margintwo solvers · 60 analysesjoints moment-continuous — the dominant simplification

Result

The two damper representations are not interchangeable. The constant 0.55 N·m stand-in is the right input to the NASA-STD-5017 torque-margin budget, but carried into the dynamics it overstates the loads: the rate-proportional law cuts peak deployment member loads by 95 percent. Fitting that damper also reverses which deployment sequence is worst, through a second and independent mechanism — damping is lost when a line latches, so the sequence that finishes a line early dissipates least and arrives with the most energy.

Two checks bound the method. Rigid-body deployment analysis of the flexible array is good to about 1 percent of span in tip deflection and degrades sharply past 2 percent. The NASA-STD-5017 margin calculation reproduces the published Suomi-NPP / NOAA-20 outcome to within 0.006 and 0.02, untuned. All 20 configurations across the three sequences were run through both solvers, 60 analyses in all.