Can anyone interpret this data?
2013-05-13 18:31:16 GMT
Hi All, So this was the maiden test flight - a modified Madcow Piranha (dual deploy with an extra 8" of length) on a G79W (which I thought should hit 800' according to Open Rocket but barely made 550 -- weirdly Madcow's simple little iphone app predicted this!). I had installed the motor ejection charge as a precaution as I had no way to ground test it. I believe the motor ejection charge fired first - just pre-apogee (the big blue acceleration spike). Looking at the 2 ejection centrifuge canisters (with 0.5g 4F) it looks like they both fired. But the voltage drops were different - the aft drogue appeared to have a tiny drop, but the main showed a huge drop. The main was set to fire at 400' (I thought it would have been about half way down from 800', but it was only down from 550). From ground observation it looked liked the 4F charge was too small to cleanly blow the chute packages (drogue was a reefed 30") out - and they seemed to wriggle out slowly and only fully inflate a 100' or so off the ground. I think this can be seen by the relatively constant descent velocity, that only slows down just before reaching ground level. Anyway, I'd love to have your experienced read on this! It was so cool having the live GPS talking during the brief flight, had a bunch of interested folk around us at NASA Ames/Moffet Field. Cheers, Winton(Continue reading)