From db42f0a65580f031d42069dcb0406e3a08c66fd8 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Tue, 14 Oct 2008 00:01:00 -0600 Subject: [PATCH] post --- bdale/blog/posts/YikStik.mdwn | 80 +++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 bdale/blog/posts/YikStik.mdwn diff --git a/bdale/blog/posts/YikStik.mdwn b/bdale/blog/posts/YikStik.mdwn new file mode 100644 index 0000000..1d4cffe --- /dev/null +++ b/bdale/blog/posts/YikStik.mdwn @@ -0,0 +1,80 @@ +[[!tag tags/rockets]] +As some of you know, the first weekend in October was a big deal for me, +because it was [NCR's](http://ncrocketry.org) Oktoberfest launch event. +My son and I spent the weekend camped out on the prairie +with Keith Packard and many of our other friends. Keith successfully went +from nothing to a "level 2" high power certification, which was pretty cool. +I wasn't quite so lucky. + +On Saturday morning, I flew my custom-designed rocket YikStik for a "level 3" +certification attempt. The name comes from the word my wife uses to describe +lipstick. The rocket was built from a mixture of custom and +[Giant Leap](http://giantleaprocketry.com) +parts, including 98mm Dyna Wind airframe, a 98-75mm tail cone retainer, and +a Pinnacle nose cone. All the centering rings were cut on my 3-axis CNC +milling machine, and the fins were custom 7-layer composite layups using +plywood, carbon fiber, fiberglass, and epoxy... all vacuum bagged using a +kitchen food saver appliance. Painted red, gold, and black, with a custom +8 foot main parachute sewn by my wife Karen from the +[Team Vatsaas](http://www.vatsaas.org/rtv/systems/Parachutes/Chute.aspx) +design in red and black rip-stop nylon. + +The motor selected was an +[Aerotech](http://www.aerotech-rocketry.com) +M1297W reload. This is a 75mm diameter motor 66.5cm in length with 2722 grams +of propellant yielding 5417 Newton-seconds of total impulse. It was also on +sale earlier this year for cert attempts. +My simulations +said YikStik should have flown to about 14,800 feet above ground level at the +NCR north site on this motor. + +The launch went perfectly, and the rocket was stunningly beautiful under boost. +It disappeared into some high clouds, but we continued to have strong signals +from the two tracking transmitters installed in the payload bay behind the +nose cone. About the anticipated time after launch, we saw a rocket descending +under chute in the distance, and headed in that direction. A few minutes +later, we abruptly lost both tracking signals, and that's when things took a +turn for the weird. + +In hindsight, I think we suffered an apogee deployment of the main chute, and +the rocket we saw descending was someone else's. YikStik +was designed to deploy a streamer at apogee, then descend fairly quickly +to about 1500 feet above ground where a second set of ejection charges would +fire to separate the nose cone on a 3 foot drogue parachute that would pull a +deployment bag containing the main chute out of the airframe and then pull +the bag off the chute. The nose cone, payload bay with the tracking +transmitters, and deployment bag would then descend under the drogue chute and +the remainder of the rocket would descend under the big chute. In the world +of deployment bags, this is called a 'free bag' configuration. With deployment +at 1500 feet, the two bits should have landed within sight of each other. But +that didn't happen. + +It wasn't until late Sunday afternoon, after we had to leave to get Keith to +the airport, that some friends finally located the nose cone assembly about +3.5 miles down range from the launch site, over a couple rises and past an +area of rough terrain. By then it was cold, windy, and rainy, and so I really +appreciated the effort they put in locating the nose, and wasn't too surprised +that they didn't immediately see the rest. Since the bulk of the rocket under +the main should have had a slightly higher descent rate than the nose cone, +I expected to find the rest of the rocket somewhere near a line between the +launch rail and where the nose cone was discovered. So last Wednesday I +spent about 5.5 hours walking around the area searching... but no luck. +Since then, several other people have been out looking for my rocket, +including two friends who flew over the area today in a light plane looking +down into all the washes. Still nothing. + +I posted some signs in the area with a photo of the rocket and my contact info, +I hope someone calls eventually. In the meantime, the bulk of YikStik remains +missing, and of course I did not achieve a successful level 3 certification. + +Lessons learned for next time are that tethering the deployment bag to the +main chute instead of flying in a "free bag" configuration might have been a +better choice, and it's kind of silly having two tracking transmitters in one +of the two pieces of your rocket and none in the other... + +Ray LaPanse took some stunning photos of the launch. He will likely post +better versions with color correction and so forth at some point, but in the +meantime, I've put a few up on my +[Garbee Rockets](http://www.gag.com/rockets/projects/yikstik/launch-photos) +web site. She sure was a beauty! + -- 2.30.2