For the space geeks amongst us.

[RoadKingLarry]

Pretty cool next level model rocketry

https://www.youtube.com/watch?v=YixmPK26upk

[AZRedhawk44]

He's walking a fine line with TVC on that model.  Guidance systems are a no-no on amateur rockets, to my understanding.

[RoadKingLarry]

Would his setup be "guidance" or simply "attitude control".
While I fully understand the goobermint doesn't use (or share their version) the same dictionary as us mere mortals, to me "guidance" means directing something from point A to point B.

[dogmush]

I can find nothing in the various federal amateur rocketry regs or CFR's saying you can't control an amateur rocket.  There are limits on vehicle weight and total thrust but that's al I've found.

He also sells those flight computers ant TVC mounts on his website.  He's not being subtle if it is indeed a no-no.  https://bps.space/shop/signal-r2

Do you have more info I could read up on?  The subject is interesting.

It's a very cool project he's working on.

[MillCreek]

So those are sequential solid-fuel rocket motors on the descent?  I thought I saw the ascent motor being kicked out at apogee.

[dogmush]

So those are sequential solid-fuel rocket motors on the descent?  I thought I saw the ascent motor being kicked out at apogee.

Yeah, he identified them in later in the video.  Estess motors.  The launch motor is ejected and the landing motor slots into the TVC mount.

[RocketMan]

Guidance systems on model rockets are indeed a no-no according to NAR and Tripoli rules and guidelines.  You can get your certification yanked if you build rockets with guidance systems.
Years back some folks were building sun-seeker guidance systems into large, high power model rockets, the idea being to cause rockets to follow a consistent trajectory in an expected direction.  Because they were just a hop and a skip away from being true guidance systems the two national rocketry organizations strongly discouraged the practice.  This occurred soon after the whole BATFE "model rocket motors are explosive devices" and "model rocket flyers are incipient terrorists" debacle that took years to resolve in court, and no one wanted to rouse the ire of the Feds again.
I didn't watch the entire video, but I have a hunch this guy is not a member of either of the national rocketry organizations.  The motors he is using might be home made, and they seem to be mid-power, not high power, but that can be hard to determine just by watching a video.  You don't need to be certified to fly mid-power rocket motors (E-G class motors).

edited to add:  Estes does not build high power rocket motors that require certification to fly.  Their largest motors are G class motors.

[RoadKingLarry]

He states in the video that he is using Estes F motors.

[kgbsquirrel]

Neat stuff.

[AZRedhawk44]

Guidance systems on model rockets are indeed a no-no according to NAR and Tripoli rules and guidelines.  You can get your certification yanked if you build rockets with guidance systems.
Years back some folks were building sun-seeker guidance systems into large, high power model rockets, the idea being to cause rockets to follow a consistent trajectory in an expected direction.  Because they were just a hop and a skip away from being true guidance systems the two national rocketry organizations strongly discouraged the practice.  This occurred soon after the whole BATFE "model rocket motors are explosive devices" and "model rocket flyers are incipient terrorists" debacle that took years to resolve in court, and no one wanted to rouse the ire of the Feds again.
I didn't watch the entire video, but I have a hunch this guy is not a member of either of the national rocketry organizations.  The motors he is using might be home made, and they seem to be mid-power, not high power, but that can be hard to determine just by watching a video.  You don't need to be certified to fly mid-power rocket motors (E-G class motors).

edited to add:  Estes does not build high power rocket motors that require certification to fly.  Their largest motors are G class motors.

Something I've learned from my time as a Ham Technician, is that most organizations suck.  And I love hacksmiths and arduino and pi enthusiasts.  All Hams want to talk about is radios.  They don't want to use their radios to actually do anything in their lives, most of the rules to Hamming prohibit amateur radio from being actually useful for anything.

I assume that most rocketry clubs follow similar tendencies.  The guy in this video looks inspired by SpaceX and NewSpace, and wants to experiment with similar concepts... which is near impossible without TVC, altimeters, inertial sensors and other low grade arduino level toys.  You could even throw an arduino GPS on if you wanted to, as long as you didn't have your craft going so fast that the GPS hit its mandatory deactivation speed for commercial use.  All of these are things that a hobbyist hacksmith will immediately gravitate towards in order to solve his problem, but the rocket enthusiast club would hold debates and meetings and fear the ire of some government feeb or other, and counsel against or even make club bylaws against.

None of this is aimed at you, personally, RocketMan.  Just at the scope of fear and state terrorism projected against dreamers and tinkerers that stops them from doing awesome *expletive deleted*it.  And that includes weaponizing things.

How many John Brownings have gone by undiscovered with an amazing concept, because cottage industry is effectively dead for weapons and aerospace applications?

[dogmush]

Guidance systems on model rockets are indeed a no-no according to NAR and Tripoli rules and guidelines.  You can get your certification yanked if you build rockets with guidance systems.
Years back some folks were building sun-seeker guidance systems into large, high power model rockets, the idea being to cause rockets to follow a consistent trajectory in an expected direction.  Because they were just a hop and a skip away from being true guidance systems the two national rocketry organizations strongly discouraged the practice.  This occurred soon after the whole BATFE "model rocket motors are explosive devices" and "model rocket flyers are incipient terrorists" debacle that took years to resolve in court, and no one wanted to rouse the ire of the Feds again.
I didn't watch the entire video, but I have a hunch this guy is not a member of either of the national rocketry organizations.  The motors he is using might be home made, and they seem to be mid-power, not high power, but that can be hard to determine just by watching a video.  You don't need to be certified to fly mid-power rocket motors (E-G class motors).

edited to add:  Estes does not build high power rocket motors that require certification to fly.  Their largest motors are G class motors.

For my clarification, just because I'm suddenly interested:

* US Law requires "certification" to buy high powered rocket motors (Above G class)
*Only the National Association of Rocketry and Tripoli Rocketry Accusation currently issue those certifications in the US (info from here: https://www.nar.org/find-a-local-club/section-guidebook/laws-regulations/)

As long as you aren't using "High Power Motors" (any motor whose average thrust is above 80 Newtons, or above G class) you don't need their certs.

So the "no guidance" thing is more of a "keep the club happy to keep your cert" guideline rather than a hard "law"?

[MillCreek]

Are there such things now as consumer-level liquid fuel rocket motors, or is solid fuel still the only way to go?

[Ben]

You know what, screw the feds and their lame ass rules. People can riot and burn buildings down and that's cool self-expression, but they would go after someone like this?

What this guy is doing is super cool stuff that intelligent and inquisitive humans should be doing. If we had more young guys like him getting the same enjoyment from science as he does, the world would be a better place.

Really neat stuff. Thanks for posting the video.

[dogmush]

Are there such things now as consumer-level liquid fuel rocket motors, or is solid fuel still the only way to go?

Liquid fuel engines are a lot more complex to get working right.  Even if you stay away from the more.....frisky fuels and use something like meth/LOX I'm not sure how you'd scale the turbopumps down.

[MillCreek]

What this guy is doing is super cool stuff that intelligent and inquisitive humans should be doing. If we had more young guys like him getting the same enjoyment from science as he does, the world would be a better place.

Quoted for truth.

[kgbsquirrel]

Liquid fuel engines are a lot more complex to get working right.  Even if you stay away from the more.....frisky fuels and use something like meth/LOX I'm not sure how you'd scale the turbopumps down.

You end up with electric motors driving the pumps rather than preburners, ala the Electron Rocket.


Fun fact: you need a minimum of about 9,500kg of rocket booster stack to put 1kg into low orbit.  This is achieved using liquid fuels with a specific impulse in the mid 300's.  Solid fuel has a lower specific impulse so you will in turn need even more booster to get your payload halfway to anywhere.

I have no idea what motor class it would be but you're lookin at first sea level thrust of around 20-30 kiloNewtons.

[kgbsquirrel]

You know what, screw the feds and their lame ass rules. People can riot and burn buildings down and that's cool self-expression, but they would go after someone like this?

What this guy is doing is super cool stuff that intelligent and inquisitive humans should be doing. If we had more young guys like him getting the same enjoyment from science as he does, the world would be a better place.

Really neat stuff. Thanks for posting the video.

His path is one of personal ability and agency.  So it must be destroyed lest it destabilize the social order.

[dogmush]

You end up with electric motors driving the pumps rather than preburners, ala the Electron Rocket.

I'm familiar with the Electron, But I thought that was kinda as small as you could get one, and it's still a 60ft tall rocket.  Wiki says each pump on those engines is running at 50 HP.

I'm not an actual rocket engineer, but it would seem that unless you used a pressurized fuel tank (heavy, and hard to do on a model sized rocket) you'd need, at minimum,  a pump that could exceed combustion chamber pressure at enough volume to keep the motor running.  I'm not sure you could get an electric motor strong enough, small enough to fit on an engine that would fit in a 60 or 70 mm model sized rocket.  Maybe some of those crazy brushless DC drone motors would have enough torque to do it.

[kgbsquirrel]

I'm familiar with the Electron, But I thought that was kinda as small as you could get one, and it's still a 60ft tall rocket.  Wiki says each pump on those engines is running at 50 HP.

I'm not an actual rocket engineer, but it would seem that unless you used a pressurized fuel tank (heavy, and hard to do on a model sized rocket) you'd need, at minimum,  a pump that could exceed combustion chamber pressure at enough volume to keep the motor running.  I'm not sure you could get an electric motor strong enough, small enough to fit on an engine that would fit in a 60 or 70 mm model sized rocket.  Maybe some of those crazy brushless DC drone motors would have enough torque to do it.

Liquid engines can be very small.  That's what reaction control thrusters are.  They can also omit pumps entirely and use a pressurized propellant.

ETA: I think this says it best https://youtu.be/B9mNNA2gEF8

[dogmush]

Liquid engines can be very small.  That's what reaction control thrusters are.  They can also omit pumps entirely and use a pressurized propellant.

ETA: I think this says it best https://youtu.be/B9mNNA2gEF8

Oh yeah.  I guess I knew that.  I had forgotten that use case.  I was stuck thinking about scaling down something like a Merlin.  I remembered the presurized propellant, but figured pressure vessels would have too much mass for a hobby sized rocket.

I guess I'm off to Amazon for some red fuming nitric acid. 

[MillCreek]

I wonder about hypergolic fuels, but the sticky wicket is being able to handle it safely.

[dogmush]

I wonder about hypergolic fuels, but the sticky wicket is being able to handle it safely.

Have a steady supply of interns/helpers?

[RocketMan]

Something I've learned from my time as a Ham Technician, is that most organizations suck.  And I love hacksmiths and arduino and pi enthusiasts.  All Hams want to talk about is radios.  They don't want to use their radios to actually do anything in their lives, most of the rules to Hamming prohibit amateur radio from being actually useful for anything.

I assume that most rocketry clubs follow similar tendencies.  The guy in this video looks inspired by SpaceX and NewSpace, and wants to experiment with similar concepts... which is near impossible without TVC, altimeters, inertial sensors and other low grade arduino level toys.  You could even throw an arduino GPS on if you wanted to, as long as you didn't have your craft going so fast that the GPS hit its mandatory deactivation speed for commercial use.  All of these are things that a hobbyist hacksmith will immediately gravitate towards in order to solve his problem, but the rocket enthusiast club would hold debates and meetings and fear the ire of some government feeb or other, and counsel against or even make club bylaws against.

None of this is aimed at you, personally, RocketMan.  Just at the scope of fear and state terrorism projected against dreamers and tinkerers that stops them from doing awesome *expletive deleted*it.  And that includes weaponizing things.

How many John Brownings have gone by undiscovered with an amazing concept, because cottage industry is effectively dead for weapons and aerospace applications?

Actually, rocket folks use a ton of fancy electronic gadgets in their rockets, and have for a long time.  Altimeter systems for recovery deployment and altitude determination.  The altimeters are often barometric, accelerometer or GPS-based, or a combination of these.  Arduino and other battery powered computers are used extensively for instrumentation of various types.  This instrumentation is often used to transmit rocket performance parameters back to ground stations in real time.  Other folks are doing atmospheric research of various types with large high power rockets.  School groups do this a lot.
There are electronics used for staging multistage rockets.  Of course there are HD cameras used out the ying-yang.  Some store video on SD cards, others transmit video and audio real-time back to ground stations.
The high altitude folks have to use radio tracking to find their rockets.  Many get their ham licenses and use radio tracking gear that operates in the 70CM or higher bands.  GPS is often part of that tracking gear, so the rocket can transmit its exact location back to the folks on the recovery team.  That makes it much easier to find a rocket that went to over 100,000 in altitude and out of sight downrange many miles.

[RocketMan]

For my clarification, just because I'm suddenly interested:

* US Law requires "certification" to buy high powered rocket motors (Above G class)
* Only the National Association of Rocketry and Tripoli Rocketry Accusation currently issue those certifications in the US (info from here: https://www.nar.org/find-a-local-club/section-guidebook/laws-regulations/)

As long as you aren't using "High Power Motors" (any motor whose average thrust is above 80 Newtons, or above G class) you don't need their certs.

So the "no guidance" thing is more of a "keep the club happy to keep your cert" guideline rather than a hard "law"?

US law does not require operator certification.  High power rocketry is self-regulated by the two major national rocketry organizations, the National Association of Rocketry, and the Tripoli Rocketry Association.  They handle all high power certification in the USA.  Class 2 and Class 3 rockets flyers should be certified by one of the national associations, but their is no federal regulation or law that requires such.
FAA regulations do define what is considered a high power rocket and what requires a FAA waiver for launch.  The waiver is to ensure the area is safe for other users of the airspace.
The waivers also require flights to be sub-orbital, or ballistic in nature.  Different waivers are required for orbital flights, and no amateur has applied for one to my knowledge.

A Class 1 model rocket is defined under 14CFR 101.22 (a):
"Class 1—Model Rocket means an amateur rocket that:
...(1) Uses no more than 125 grams (4.4 ounces) of propellant;
...(2) Uses a slow-burning propellant;
...(3) Is made of paper, wood, or breakable plastic;
...(4) Contains no substantial metal parts; and
...(5) Weighs no more than 1,500 grams (53 ounces), including the propellant."

A Class 2 high power rocket is defined under 14CFR 101.22 (b) "Class 2—High-Power Rocket means an amateur rocket other than a model rocket that is propelled by a motor or motors having a combined total impulse of 40,960 Newton-seconds (9,208 pound-seconds) or less."

A Class 3 rocket is defined under 14CFR 101.22 (c) "Class 3—Advanced High-Power Rocket means an amateur rocket other than a model rocket or high-power rocket."

[RocketMan]

Are there such things now as consumer-level liquid fuel rocket motors, or is solid fuel still the only way to go?

One of the founding members of Oregon Rocketry had a vernier motor from an Atlas rocket that he intended to build a rocket around.  Don't know much about his project, but the motor was really cool.  He brought it out to a launch on a trailer one afternoon.