The longest glide duration for an RC model was a staggering 36 hours and 3 minutes. I discovered this when looking for common glide ratios. It puzzled me for a while, and I decided to look into it.
Usually gliders can hitch a ride on columns of rising air called thermals. As the sun warms the ground, the warm air begins to rise, causing an updraft. Birds and gliders, and unfortunately sometimes rockets, can tap into this rising air and stay aloft for hours. But I had to think about it... 36 hours goes through the night, needless to say, and so obviously there would be no sun out to cause the thermals.
So I did a little bit of research, and found that there is another technique used by gliders to stay aloft: ridge-soaring. As the wind hits a slope, it is deflected upwards, so there is a stream of rising air right over a slope. This world record glide was simply hand-tossed from a slope and kept in the rising air for 36 hours.
There's some big news going around in the rocket community (I've heard this from about five different sources now). The rocketry associations NAR and TRA have been waging a legal battle against the BATFE (Bureau of Alcohol, Tobacco, Firearms and Explosives) for several years, which was recently won. Until now, ammonium perchlorate composite propellants (APCP) couldn't be obtained without a Low Explosives User Permit (LEUP, everything has an abbreviation), except for mid power rockets. Now, the rocket people of NAR/TRA has convinced the court that APCP is NOT that dangerous, and thankfully us saferocketeers have one less hassle to deal with.
There are also a few other new regulations that give rocketeers a break. For mid-power rockets weighing between 1 and 3.3 lbs, you no longer have to request a NOTAM. That's nice, because I never did it anyway! (Don't tell anyone!)
However, there are a few regulations at the upper end of the spectrum that make it more difficult for rocketeers. It has to do with experimental rocketry over O power, and I don't know the details. However, (and government always does things backwards it seems) I do know that increasing regulations in the experimental category isn't as effective, because people in that field ought to know what they're doing at that stage! But oh well, it doesn't effect me yet.
"Untitled" Length: 48 in Diameter: 3 in Payload: camera, altimeter Max. altitude: ~3,000 ft Max velocity: mach 0.5 Max acceleration: 350 ft/s/s No. stages: 2 MMT: 29mm-29mm Intended motors: G64 to F40 or G64
I'm VERY excited about this one. It's my first composite motor staging attempt, and (once again) I'm being pretty ambitious. This will also be the first rocket to use the altimeter to deploy the chute, and I haven't the faintest idea how that works.
I'm trying to do a SUPER job on this one, spending extra time shaping airfoils, glassing airframes, polishing, and fitting together every piece. I love engineering!
By the way, as usual, I can't think of a name. So if you have any ideas, I'd appreciate it!
I've recently purchased a 2.4 GHz video camera from BoosterVision.com. I haven't flown it yet, I'm working on a rocket that will carry it. I think there are a few drawbacks to wireless transmission, and there are a few drawbacks to internal memory. The drawbacks to wireless transmission are that the video quality isn't always that good, and the rocket can only go so high before the signal to the ground is lost. The drawbacks to internal memory include reasons like if the video camera falls out of the rocket or the rocket is lost, you don't have the video of the flight. Also (this may just be my experience), some digital video recording devices can't take the stresses of liftoff. My Flip Video F260B kept coming back with its memory blank, but after a bit of troubleshooting I discovered the batteries were coming loose under the high g-forces. This could probably be fixed with a little soldering, but the camera is now in the grave.
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I tested the video camera out in my RC helicopter, and it worked fairly smoothly. The video is on VHS, and I'm scratching my head wondering how to get it onto the computer. The receiver can also be plugged into a camcorder, but I haven't tried that yet.
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Here's a video from YouTube of a hybrid rocket. I can't tell if this was taken from a transmitting camera or an internal memory digital camera, but it does look rather clear. Hybrid rocket motors are pretty unique. They combine a liquid oxidizer with a solid fuel. The fuel is usually a simple substance like rubber or even paper, and the oxidizer is typically nitrous oxide, commonly known as "laughing gas." Before launch, the oxidizer tank has to be filled from the LCO desk about a minute before launch. When ignited, the two substances mix together in the cumbustion chamber to create a bright, smokeless flame and a loud roar. Hybrid motors tend to be even louder than standard solid fuel motors using ammonium perchlorate composite propellant, and have a unique quality of roar, as you should be able to hear in the video:
