The Starlight is another old design that was probably marginal at the time. With no nose weight, Rocksim gave a margin of .54 using a C6-5 and a margin of 1.27 with the added .2 oz. weight. I never saw a Starlight back then that was unstable, but we still added the weight for margin in our release.

I have been trying OpenRocket on our designs and the results are always more conservative. I do not know where the differences are. We always select Rocksim stability equations instead of Barrowman equations for stability calculations. Perhaps OpenRocket uses the older, less accurate equations. Probably half of our kits would be marginal or unstable if we used Barrowman, yet they clearly are not. (Well the Mars Lander is clearly marginal and should never have been released. )

__________________
Carl McLawhorn
NAR#4717 L2
semroc.com