Is it legal for me to use an active control system on my high powered rocket?

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ParallelLogic

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I am building a rocket with a high powered motor in the US/Texas through my university. We will be using passive control on our design, but the question has come up - what are the laws surrounding active stabilization control systems?

I've seen articles discussing control with compressed gas thrusters and with fin rotation. There has been talk about "Autorotating" (I do not know what this means or what it entails). I have seen references to a certification required to launch a rocket with a control system.

I've seen references to NRA and Tripoli, but not to any specific laws that state in plain English that guided/stabilized rockets are not allowed to be built/launched or what regulations surround their design/launch. I have been unsuccessful in digging up any such links - please help me find links directly from the organizations that make it clear what the regulations are on stabilization control of rockets with high powered motors.

Thank you for your time
 
As a part of a university, you're free of some of the regulations the rest of us have to follow such as requiring certification to fly a high power rocket. But, it's a very good idea follow our rules (we have an excellent safety record!) and to get certified if you can. By following the certification process, you'll receive help and guidance from experienced rocketry hobbyists, your university will probably be able to use the resources (launch equipment and site) of your local rocketry club, and you'll be able to fly high power rockets on your own at the club's high-power launches.

This subject has been brought up for discussion many times and no one has been able to cite any specific regulations against active stability (and, I'm not sure why anyone would expect there to be rules against it). It is against the safety code (and probably some laws) to aim a rocket at a physical target, but it is clear that you are not considering anything like that.

-- Roger
 
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Is it technically legal? Likely so.

Will doing anything other than making the system keep the rocket going straight up generate more attention than you likely want? You bet.

There have been a few hobby articles published about active stabilization, to keep the rocket on a straight course. That likely won't generate much governmental scrutiny, though I don't know for sure, as I'm not a lawyer.

Another factor to consider is if you're doing this as part of a university project, and you work on any sort of guidance, you may run afoul of ITAR.

-Kevin
 
Kevin, I don't understand the paranoia that's often expressed when this topic is brought up. Government agencies, such as DARPA, often sponsor events where they encourage univerisity students to develop projects such as the one described. They encourage innovation and learning. One of the USLI teams that flies with one of my clubs is designing an active system. Florida Space Grant sponsored another local university team that's been working on an advanced project with active stabilaztion for several years. I'm sure there are many more examples.

-- Roger
 
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By following the certification process
I'll refer the certification process to my team lead. I'm working on the electronics payload - I'll probably make a post about it in the Plans forum later, I need to draw up the "schematic" of the components I plan to use

I'm not sure why anyone would expect there to be rules against it
The way my team lead presented it, since we couldn't quickly prove at launch that our rocket wasn't a guided missile, then the regulatory agencies outright banned any control systems. That didn't fly with me, so that's why I'm asking here.

Will doing anything other than making the system keep the rocket going straight up generate more attention than you likely want? You bet.
Heh, we're only looking at going straight up. We're using a GPS and transmitter to find it as it's coming down

Another factor to consider is if you're doing this as part of a university project, and you work on any sort of guidance, you may run afoul of ITAR
It's for a club on campus
 
The way my team lead presented it, since we couldn't quickly prove at launch that our rocket wasn't a guided missile, then the regulatory agencies outright banned any control systems.

It's simple. A guided missile is a weapon. You're not designing a weapon. Therefore, you are not designing a guided missile.

A longer answer can be posed as a question ... if a team of univeristy students can build a guided missile for $xxx in x amount of time, why does the government use hundreds of people and spend millions over decades to do the same thing?

-- Roger
 
ParallelLogic, feel free to PM me. I won't speak on behalf of or for NAR, TRA, or the govt, but may give you some insight about similar projects that I've seen fly in the past. Would prefer not to discuss in a public forum.
 
Look up Zunofark Sunseeker.
The paper that comes up with that search is a pretty good introduction to the subject. It's pretty out-of-date, though. I had to chuckle at this:

The Japanese company muRata (that's the way they spell it on their
literature) makes a very compact, piezoelectric solid state rate gyro
that measures only 25 x 25 x 58mm and weighs only 45g. It is extremely
resistant to temperature, shock and noise. The down side is that it runs
$200 and that's for only one axis! If you're still interested, contact:

These days you can get a 3-axis gyro that's 4mm x 4mm x 1mm, weighs less than a gram, and costs under $10. I don't have the specs for the mid-90's muRata one, but I bet it's worse than what's in everybody's iPhone 4 and WiiPlus remote right now.
 
The Electronic Code of Federal Regulations (e-CFR) is a currently updated version of the Code of Federal Regulations (CFR). It is not an official legal edition of the CFR. The e-CFR is an editorial compilation of CFR material and Federal Register amendments produced by the National Archives and Records Administration's Office of the Federal Register (OFR) and the Government Printing Office. The OFR updates the material in the e-CFR on a daily basis. The current update status appears at the top of all e-CFR web pages More. You can most everything there.

You will find:
  1. There are many laws and regulations that prohibit individuals and organizations rom making or operating weapons including guided or unguided rockets with the intend to do harm.
  2. The launching of all rockets other than a Class 1 rocket by any individual or organization are tyrpically prohibited without an FAA waiver, but a waiver making it legal is not difficult to obtain.
  3. There are no laws that prohibit an individual or orgaization from putting a guidance system, either active or passive, in a legal rocket that is not a weapon for trajectory control or safety.
  4. NARr and TRA are nonprofit hobby organizations with no legal authority to enforce any civil regulations.
  5. NAR and TRA are private membership organizations that can develop and enforce their codes of conduct upion their membership and their guests at their sponsored launches provded that their codes of conduct are not in violation of federal, state or local law.
Bob
 
It's simple. A guided missile is a weapon. You're not designing a weapon. Therefore, you are not designing a guided missile.

A longer answer can be posed as a question ... if a team of univeristy students can build a guided missile for $xxx in x amount of time, why does the government use hundreds of people and spend millions over decades to do the same thing?

-- Roger

Just my opinion, don't really know about this, but after 24+ years in the military, I'm guessing this is exactly why guided hobby rockets may generate scrutiny by the Feds. We know it's not meant to be a weapon, but from the Fed's point of view, a guided hobby rocket is only one step away from a guided weapon.

From military experience a rocket guided to just fly straight is a whole bunch cheaper than a rocket guided to a stationary or moving target.


But, i think this is a cool project, hope you can make it work. Keep us posted.
 
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It's simple. A guided missile is a weapon. You're not designing a weapon. Therefore, you are not designing a guided missile.

A longer answer can be posed as a question ... if a team of univeristy students can build a guided missile for $xxx in x amount of time, why does the government use hundreds of people and spend millions over decades to do the same thing?

-- Roger
Not exactly. The reason why a team of university students today can built guidance systems cheaply is because the government spent billions of dollars over the past 6 decades to figure out how to do it.

Just my opinion, don't really know about this, but after 24+ years in the military, I'm guessing this is exactly why guided hobby rockets may generate scrutiny by the Feds. We know it's not meant to be a weapon, but from the Fed's point of view, a guided hobby rocket is only one step away from a guided weapon.

From military experience a rocket guided to just fly straight is a whole bunch cheaper than a rocket guided to a stationary or moving target.

But, i think this is a cool project, hope you can make it work. Keep us posted.
You are absolutely correct. Building a guidance system to help a rocket fly straight is a lot simpler and cheaper than to build a tracking/targeting system to weaponize a hobby rocket. I really doubt the government is very worried about hobby rocketry from a security standpoint.

The current real world terror threat is the rogue hobby drone builder. Hobby UAV drone technology is cheap, accurate and available world-wide right now. For about $5K you can built an electric powered UAV drone with a gps corrected INS that can deliver a multi-kilogram payload to a target with meter level accuracy over several hundred kilometers. For $50K a determined, well educated terrorist coud acquire a private plane and use a hobby drone INS to deliver a several hundred kilogram package to within a few meters of a target at 1000 km. It's particularly easy when you make it single use.
 
As others have said, as long as you aren't building a system that tries to guide the rocket towards a target you should be OK. I'm not sure who you would need to ask about something like. Agencies that don't know won't be able to help you and the ones that do know probably will be reluctant to give you a straight answer. You have a sort of Catch 22 situation on your hands.

I have seen a video of someone who gimbaled a model rocket motor. It was discussed on several threads on this forum. The problem with this method is that most model rocket motors only burn for 1 to 3 seconds. This doesn't give you much time to correct flight anamolies. And once the motor burns out you no longer have an active control system.

As you mentioned, controlling the fins or using some sort of secondary thrust system would seem like a better method.

There is a possibility that you might run into ITAR issues, especially if you have foreigners involved on the project.
 
to clarify for some, i think Bob's first posting was excellent.

a weapon, is an item that is intended to inflict harm... therefore a "hobby rocket" is never a weopon.

this would require proof, of use with intent to do harm. or the act of using it as a weapon itself.

a lamp, is a "dangerous weapon"... you cant be arrested for walking down the road with one, but you can be "after you do or intend to do harm."

that means guidance system, and rockets alone are not an issue. but, if there are emails, associate participation, and other elements that can paint a picture of harm. you will be hit with "constructive possesion" of dangerous weapon.

IF you move onto Bob's second post, I wish he hadnt gone full on drone... there was a guy arrested not but a few months ago, trying to obtain H.E. for his drone.(GPS guided F4 phantom) they didnt care about his "aircrafts" capability, until then. there were multiple documents where it was stated they guy was under survailance and not a threat untill the attempted procurement of H.E. (not a threat, until he tried to get explosive)

theres another guy that makes pulse jet drones, he is from newzealand, his site about making a 5k cruise missile is down right creepy.


IMO, in the laws of the universe, an automated guidance system can be proven no more a weapon, than a manual guidance system"R/c" (which is fairly prevailant.) Both show the user can inflict intent, if it was present.
 
I oo wanted to biuild a finle rocket using a gimbaled motor mount, however the response I got when asking about this from my local club. "Not on our field!" Seems the bigger issue will be finding a place to fly the rocket. For me not being university tied, I have to use inplace flying arrangments, and it would seem that most are unwilling to allow it. It would seem that this walks a grey line that nobody seems to understand. I thought it would fall under TRA research rules, but apparently that is for building your own rocket motors not building guidance systems.

I will say that I have an uncle who does electornics engineering for a living and according to him 4 seconds is a long time for anything electronic. The issue for me is the coasting phase, and because I don't want to create a finned rocket, I was trying to correct with a pendulum. But that might not work eighter.

Best of luck to you. Another thing when did we as americas decide that the government was out to get us?
 
Seems the bigger issue will be finding a place to fly the rocket.
If I were RSOing a rocket that could be unstable without active guidance, I would be asking some detailed questions about what bench and flight testing had been done to provide some assurance that the active guidance would work; that only seems reasonable. If a club didn't have anyone qualified to review such a design, it would be prudent IMHO to not let it fly.

Of course, I would be less worried about a smaller motor than a larger one.
 
I think we may be confusing the term guided with homing. A guided rocket would be one that uses a system to control the direction of flight and alter that path according to a pre determined set of criteria. A homing rocket would be one that uses a system to guide the rocket to a defined point in space, which of course requires a guidance system and a method of determining the point to which the rocket will home (gps, laser, internal map or coordinants). Either could be construed as having the potential of being weaponized. An unguided rocket could as well, although the argument is somewhat suspect due to the inherent inaccuracy of unguided rockets.

As to Clay D's comment about intent, I wouldn't care to tempt the powers that be and be forced to prove my intent is different from theirs.
 
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Wow. I think some tin-foil hats need to be loosened a bit. :)

There's nothing wrong with working on a active stabilization system for a hobby rocket. There are no laws against it. There are no black helicopters circling waiting to pounce on anyone trying it. And, it doesn't make a rocket into a weapon.

Hobbyists and students have experimented with it and there's no evidence of it raising any government scrutiny other than some groups receiving grants or other awards to help them continue their work.

-- Roger
 
I was talking with a friend about this topic the other day, and learned from him that there are some books available on active guidance systems from Amazon. They're not cheap -- the ones he showed me were in the $350 price range.

Unfortunately, I didn't save the links. :rolleyes: Otherwise, I'd post them here.

Stabilization systems that help keep a rocket on a vertical flight path could be handy!

-Kevin
 
I was talking with a friend about this topic the other day, and learned from him that there are some books available on active guidance systems from Amazon. They're not cheap -- the ones he showed me were in the $350 price range.

Unfortunately, I didn't save the links. :rolleyes: Otherwise, I'd post them here.

Stabilization systems that help keep a rocket on a vertical flight path could be handy!

-Kevin

save some headache,,, https://www.sparkfun.com/products/10736
plus another 100.00 and your good to go.
 
Best of luck to you. Another thing when did we as americas decide that the government was out to get us?

Anyone who does not believe our government is out to get us, please check out this video, the good part starts about 1/4 of the way in. I don't know this guy, and certainly am NOT campaigning for him, but he has some very interesting things to say.

https://www.youtube.com/watch_popup?v=7n2m-X7OIuY





Wow. I think some tin-foil hats need to be loosened a bit. :)


-- Roger
I threw mine away years ago, heard the focused brain waves cause insanity. :)
 
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The primary problem with active guidance is of a practical nature. It is hard to do right. If you want to fly it on a public launch you really don't want to steer it into the wrong direction by accident. It is relatively easy for an RSO to check if a rocket as passively stable. It is, for practical purposes, impossible for the RSO to do the same with an actively guided or stabilized rocket. Therefore "Not on my range!" comments aren't surprising.

Last year I've been to an experimental launch in France, hosted by CNES on a missile test range (DGAEM Biscarosse), and they were quite explicit about this. The only thing that they would allow, is simple roll control, with the condition that the steerable fins are mechanically coupled in a way that only torque on the roll axis could be exerted. Two or four individually controllable fins were not allowed - no matter how the software behind them looked like. Apparently the only acceptable way to do active guidance was in conjunction with a range abort system, which was way beyond the scope of the event.

If you want to fly an actively guided rocket, I'd suggest to keep it rather low profile for different reasons. Avoid to fly the rocket in front of big crowds. If the guidance system works not as intended, you don't want unnecessary people around that might be harmed.
Plan your flight profile around safety. For example you can design your rocket in a way that it stays passively stable and you delay activation of your control system until the rocket is high up in the air. If something goes wrong late in the flight, it will likely have less severe consequences.
Probably not an issue for you, but I mention it anyway: Keep it "small". Unless you really know what you're doing and you can present this in a convincing way, don't even consider approaching FAA with the intent to fly an active controlled class 3 rocket.

Reinhard
 
Ok folks, time to play semantics; And YES we need to because the Feds do.
First are we talking "Active Stability" or "Active Guidance"? Active stability is simply keeping the thing going straight. I recall old articles in HPR Mag about a "Sun Seeker" and another on "Rollerons". These are Active forms of stability and ok to employ. Active Guidance is the ability to stear a projectile or vehicle from a balistic flight path and/or to a specific point. By definition this is the difference between a "Rocket" and a "Missile". It dosn't matter how WE want to define it, that's how the GOVERNMENT defines it. Guidance does not make it a weapon but a warhead does. Guidance just makes it a Delivery System. This is why the Fed percs up when they hear of it and why WE, the hobby comunity, try to stear clear. Just as a reminder, the V2 was Stabelized with active systems but was not "Guided" in the sense we're talking here. It flew a calculated ballistic trajectory. The stabelization system simply compensated for exterior forces. FWIW
 
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I vote we press gang Adrian in to do it. After the Perch and the new Tilt sensor-it's only logical. Who gets to nag him about THAT? I've done my share of scolding (see his post) so who wants to volunteer for this one?

(Hmm- active stabilization for $50....hmmm...)
 
Ok folks, time to play semantics; And YES we need to because the Feds do. [...] It dosn't matter how WE want to define it, that's how the GOVERNMENT defines it.

Can you please cite a reference?

-- Roger
 
I vote we press gang Adrian in to do it. After the Perch and the new Tilt sensor-it's only logical. Who gets to nag him about THAT? I've done my share of scolding (see his post) so who wants to volunteer for this one?

(Hmm- active stabilization for $50....hmmm...)

Last year I took up RC gliders too, so yeah, I've been thinking about it. Once I get the tilt sensor working, I'll have most of the technology under my belt. But who said $50!!??:no:

I like the idea of keeping it mechanically simple and just hooking 2 canards directly to 2 beefy servos. That will cover pitch and roll. To yaw, the system would have to roll first to align the desired rotation to the pitch axis.

My long-term goal is an N5800-N5800 to space. Really tiny off-vertical angles cause 10s of miles of downrange distance for a flight like that, so it's possible that active stabilization will be more feasible than trying to keep it going that straight passively.
 
Last year I took up RC gliders too, so yeah, I've been thinking about it. Once I get the tilt sensor working, I'll have most of the technology under my belt. But who said $50!!??:no:

I like the idea of keeping it mechanically simple and just hooking 2 canards directly to 2 beefy servos. That will cover pitch and roll. To yaw, the system would have to roll first to align the desired rotation to the pitch axis.

My long-term goal is an N5800-N5800 to space. Really tiny off-vertical angles cause 10s of miles of downrange distance for a flight like that, so it's possible that active stabilization will be more feasible than trying to keep it going that straight passively.
The easiest way to actively control and correct for vertical flight deviations is to make a forward payload compartment with 2 axled sets of balanced canards and utilize the x- and y- axis tilt sensors to drive the x- and y- tilt controlling servos connected to the canards. The rocket stability will be largely controlled by the rear fins while the foward canards simply pitch the nose over to keep the trajectory vertical. The best part of this is that a single "dumb" control system will control verticallity regardless of number of stages and whether the motor is thrusting or burned out. There is no reason to worry about roll with this control system, so the overall system is much, much simpler mechanically and electronically than other methods.

For ground testing, you simply neaf to tilt the canard section around centerline and all the fins should remain vertical for reasonablr airframe angles. Your control algorithm does need to limit angle versus velocity to prevent g-load failures at high velocity, but this should also be straight forward.

Bob
 
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