Bob Space

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I spent part of last night taking the equations for three-angle elevation-only tracking, working them into my TI-83 Plus, and then checking them against problems worked using the tables in the Handbook appendix. They seem to work fine, and I rather like the mathematics underneath (which I can actually understand in this case). (The Pink Book’s two methods don’t yet make sense to me. I’m sure they would, if I worked at it.)

And I placed my first mail order with Quest … the one, maybe two, stores that have anything like a selection in model rocketry being an inconvenient dozen miles across town. Spare igniters, spare wadding, 2 sets of their light-weight altitude trackers, and two or three kits.

My nap today was totally obsessed with designing a booster stage to turn an Estes Alpha or Quest Astra into a two-stager. My subconscious apparently insists I do this. And given the limited flight space, it looks like I need to do this as two A-powered stages.

(grin) I like a hobby with challenges.

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Spanish Springs High School is built in three terraced levels, each roughly 100 yards wide and several hundred yards long. The upper athletic field would be satisfactory, maybe, for B–engine flights but nothing more. And the slightest wind would take the vehicle down onto the parking/football stadium terrace, or (murphy says) all the way down to the roofs on the building-level terrace.

Alternate back-up: Shadow Mountain Sports Complex (City of Sparks). Good clear space, probably safe for C-, maybe up to D-, powered flights. Problem: … actually, not a problem. There are several access roads cut across the sports fields, so I can have a dry grass-free launch point. Problem is that it’s usually hideously busy. But it’s very convenient. We’ll have to give it a try.

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After research, I’ve learned that gas-powered RC models aren’t allowed in county parks, either. If the administration is THAT skittish of fires, it’s no surprise that I haven’t heard back on my request for permit information.

Well, that leaves me: City public parks (none of which are big enough, and most of which are infested with rocket-eating trees), state/federal public land, and finding a private property owner of cooperative spirit. There’s a nice chunk of BLM land over near the Evil Big Box Discount Store, but it’s awfully hilly and apparently used as a firearms range. Other public land of that sort will be a substantial drive, but probably doable. A quiet part of Sand Mountain would do the trick.

Private property is the usual solution, it seems. The trick is finding someone with 20-50 acres they’re willing to let us operate in. (No, not buying any land for this. Land is hella expensive.)

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Removed the invocation of TI calculators, replaced with Palm PDA and links to Steven Hortensius’s excellent Palm OS programs for rocketry. As much as I like reinventing the wheel, when someone’s already got a rounder wheel than I could invent, it’s only sane to use it.

Did shopping for the build and range boxes yesterday. More to be done… extra wadding, igniters, a fire blanket. (I really want to find a flammables-free launch site, but the reality is otherwise.)

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Here’s what people flying model rockets in Washoe County need to know about the laws in the area.
Local Codes

State of Nevada, Washoe County Code, Reno City Code, and Sparks Municipal Code ALL use the ICC International Fire Code of 2003 as their base. They have added amendments here and there to make the local codes more strict in certain ways, but none of those changes affect model rocketry or high-power rocketry.

IFC 2003 takes its definitions of “model rocket,” “high power rocket,” “fireworks” and “pyrotechnics” from standard codes published by the National Fire Protection Association (NFPA 1122 for model rockets, NFPA 1127 for high power rockets, NFPA 1123 for fireworks display.) Model rockets must use motors manufacturer and inspected and certified as per standards in NFPA 1125. (Standards for fireworks manufacture are NFPA 1124.)

BOTTOM LINE: Model rockets are not the same things as fireworks! (Contrary to what a Washoe County Sherriff’s deputy said to me earlier this week.) Model rocket motors have been defined separately from fireworks since 1963. Fireworks are single-use devices for entertainment. They go up, they make visual and/or sound display, the end. Model rockets are re-usable devices for scientific or educational purposes or for sporting competition. They go up and they come back down wholly intact and safely via one of several defined recovery methods.

If one is abiding by the widely published Model Rocket Safety Code to the letter, one can be sure he’s abiding by NFPA 1122 … and so also abiding IFC 2003 … and so also ANY local jurisdictional codes.

But: Washoe County Code 95.230 prohibits the use of “rockets” in a county park without “written permit of the director.” I’m probably going to have to get into politics to get that amended to allow safe model rocket flight that won’t have an adverse impact on the park.

Having dispensed with the local rules, here are a few State and Federal rules to keep you warm and cozy:

State of Nevada

Nevada Revised Statute 202.262 acknowledges model rocket motors as an explosive or incendiary device but explicitly allows their possession and use under the same exemption that includes mining, agriculture, construction, etc.

Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF)

The Bureau of Alcohol, Tobacco, Firearms and Explosives published a rule clarification in August 2006 stating that the rules covering commerce in explosives (licensing, safe out of home storage, registry, logging, etc.) do no apply to model rocket motors of less than 62.5 g propellant (ANY solid propellant — APCP, black powder, or similar low explosives) or less than 62.5 g reloadable propellant. So, gang, we’re sticking with A-G motors.

Federal Aviation Administration (FAA)

The FAA says that model rockets (defined as using less than 113 g slow-burning propellant, having launch weight less than 453 g, made of paper, wood or breakable plastic, and operated in a manner which does create a hazard — has no extra regulation under FAA rules. That’s the classic model rocket definittion right there.

FAA extended the rules slightly to create a new category called large model rockets: all the rules are the same, but the launch weight of a large model rocket falls between 453 and 1500 g. (Still inside NFPA 1122, notice.) Large model rockets are not allowed to fly into clouds, or when there’s more than 50% cloud coverage, or when visibility is less than 5 miles. Flyers must notify the nearest FAA facility with flight information 24-48 hours in advance, and if they’re within 5 miles of an airport, they need to notify that airport’s manager with the same information. Notice that word: “notify.” You do not require FAA permission to fly large model rockets. You just need to let them know when, where, and how you’re flying so they can tell pilots that “whoosh” they just saw climbing below them is not an missile heading for them.

Rockets bigger than 1500 g or more than 125g propellant or made from other-than-model materials (metals or composites) have to do all that, plus not fly at night, not fly near uninvolved private property, and (the kicker) not fly in controlled airspace. Since all airspace 1200 feet above ground level or higher is pretty much “controlled” under FAA definitions, any high-power or experimental rocket must request waivers to that rule to get to fly.

For what it’s worth, I feel there’s plenty of room in the “model rocket” zone to play happily for the rest of my abbreviated life. I might try some of the E, F or G motors just to see how they run (the pictures are awesome) once my skillz are up to building an airframe strong enough to take them!

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Back when, launch systems demanded 12 V, either in a double-size lantern battery or in a connection to a motor vehicle. Estes even marketed a launch pad where you put the power supply in the pad, under the blast deflector. This was how you reduced the amount of wiring snaking around.

Fast forward 30 years, and both of Estes’s launch controllers are compact and handheld and use 4 AA batteries to generate 6 V. Hurray for portability, but it just feels wrong. And never mind that apparently the only difference between the two is that the E launch controller has 10 m launch leads (required by The Safety Code).

(The Quest controller uses a 9 V battery, but I’m leery of 9 V snap connectors which tend to break in my presence. They have a new launch support line coming along which addresses “advanced” rocketry, but I can’t find any specs on the new controller.)

And the all-in-one units just aren’t flexible. Or even pretty.

I spent much of a day thrashing on a launch controller of my own design. It would run on 12 V and have a modular launch lead, so you could swap a longer lead for a shorter, or vice versa, or even hook the controller to a switch-box, and have multiple launch pads connected to a single controller. With a car or motorcycle battery behind it, this apparatus could easily push rockets off the pad from 20 or 30 m away, and maybe push 2 or 3 at once from 10 m. But at some point in the construction I’d have to solder switches or lamp sockets or igniter clips … and this would probably go poorly.

Finally I came across Pratt Hobbies’s Go Box controller. Which does all the things I want, none of the things I don’t, it’s extensible and flexible. It’s definitely on my list for the second wave purchases. And then I bumped into their Sixpack multiple launch controller. That’s a maybe, if I end up in a club situation.

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As the weather gets colder and worser, I’m re-entering the hobby in “indoor mode”: lots of classroom and construction projects to prepare for a nicer flying season. (That said, there’s something appealing about the idea of flying rockets on an icy-clear Nevada winter morning…)

1) Training Casey: This week — parts of the model rocket, parts of the model rocket motor, model rocket motor nomenclature. She gets her copy of the Estes Model Rocket Technical Manual this week, so she can read through that at her leisure.

2) Programming: I need to rework my TI-83 Plus programs; I’d like to be able to have them all in the calculator at once without them arguing over variable storage space.

3) Preparation: I’m probably going to whomp up some full-size checklists and laminate them for range use. Casey does really well at step-by-step (for that matter, so do I!).

3) Shopping: We need tools and supplies. And containers to keep them in. Casey and I are each tackling an NAR-operated achievement program, and to complete our respective first levels Casey needs two more rockets and I need at least two and as many as four. I’m trying to shop wisely, and maybe use the same rockets for multiple missions

4) The Launch System: I’m not happy with the entry-level launch system we have now. But for the moment I’m fighting very hard against my impulses to replace it. It’s going to work just fine for at least the next 10 launches. After that, I’ll have a better idea of where I’m/we’re going with the hobby and I can take appropriate action. Waiting is.

But I find I’m really straining hard to keep things in their proper place and not make this more complicated than it needs to be. I want it to be fun … fun for me, fun for Casey, fun for those who go with us. And I keep having to suppress goofy impulses that only complicate. For example: the achievement programs give patches at each level completed. I want to get Casey and I matching jackets to stick our patches to.

This isn’t the only case where my eyes are running bigger than my mouth. Weather stations, multiple launchers, handheld radios … well, it’s already too late for those, they’re on their way … altitude trackers, portable PA, books, videos … I’m out of my mind. I expect to invest in the hobby — that’s a given for any hobby. But I just wish I had a better sense of what my future will really be like, as opposed to what I might dream it will be like. (Those of you making your own realities, please move along. I like this one, unpredictable thought it is.)

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This is my journal category for model rocketry activities. More to come.