Hello,
I am currently building a hybrid HPR and I am a little bit worried about the apogee velocity. Due to some safety issues there could be a small possibility of launching at 75° above horizon. That is pretty flat and I calculated a "worst case" scenario depending on angle and wind ... 273fps in apogee. I am a rookie if it goes to such high apogee speeds and I would like to ask you guys if you have any experience with such challenges. (its not a problem - for engineers there are no problems, just challenges!)
Short info:
I considered the usage of a two stage-system with a smaller drogue-chute (3-4ft) and a larger main paracute (deployment at 1500ft - no problem with that one). For the given "worst-case" scenario the apogee shock-load based on "Parachute Recovery Systems" (T.W. Knacke) will be around 1000lb during deployment. So I was thinking of a Mach-II chute (3ft) from rocketman as a drogue, but it is pretty heavy (approx. 2lb.) and I need so save some more weight (maybe its also overrated ... I am not supersonic during deployment). So how about an ProXP from rocketman or something else? Fruitychutes? Angle? Nobody provides max. deployment velocities.
Thanks for you help!!
s3th
I am currently building a hybrid HPR and I am a little bit worried about the apogee velocity. Due to some safety issues there could be a small possibility of launching at 75° above horizon. That is pretty flat and I calculated a "worst case" scenario depending on angle and wind ... 273fps in apogee. I am a rookie if it goes to such high apogee speeds and I would like to ask you guys if you have any experience with such challenges. (its not a problem - for engineers there are no problems, just challenges!)
Short info:
OD | 6 inches |
Length | 12ft |
Thrust | 2000lb for 10s (N2O + HDPE) |
Apogee | 16500ft |
Weight | 40lb (during descent) |
I considered the usage of a two stage-system with a smaller drogue-chute (3-4ft) and a larger main paracute (deployment at 1500ft - no problem with that one). For the given "worst-case" scenario the apogee shock-load based on "Parachute Recovery Systems" (T.W. Knacke) will be around 1000lb during deployment. So I was thinking of a Mach-II chute (3ft) from rocketman as a drogue, but it is pretty heavy (approx. 2lb.) and I need so save some more weight (maybe its also overrated ... I am not supersonic during deployment). So how about an ProXP from rocketman or something else? Fruitychutes? Angle? Nobody provides max. deployment velocities.
Thanks for you help!!
s3th