# Vertical landing model rocket

### Help Support The Rocketry Forum:

#### TRFfan

##### Well-Known Member
Is it possible to make a model rocket land vertically like the spacex rockets?

#### Steve Shannon

##### Well-Known Member
TRF Supporter
Is it possible to make a model rocket land vertically like the spacex rockets?
Not easily, because there's no aerodynamic stability at very low velocity, plus going downward your Cp is now leading Cg, unless you do something to change configuration.
You'd probably need a gimballed motor with a controller to keep the rocket upright. Ideally your main engine for landing would be a cold thruster so you would not start a fire. If you had a reservoir of gas, compressed greatly, you might be able to use it for attitude control also, which might not require a gimbal on anything.

#### Incongruent

##### Well-Known Member
Yeah but that's with a parachute. I meant with actual rocket boosters.
That's a fire hazard. And a passively stabilized model rocket that resembles a SpaceX booster even marginally is not stable going toward the ground, pointy end up, under thrust. Solid rocket motors aren't too good for this either, since gradual deceleration is better than sharp deceleration, and solid rocket motors are typically short burn. Long burn comes with additional fire hazard. Liquid... no.

It also violates the (NAR, at least) safety code, since that's not the recommended use of a rocket motor.

Vertical landing is exceedingly difficult with short legs- look at earlier attempts by SpaceX. Wider legs look less sleek and destabilize further.

#### dhbarr

##### Amateur Professional
In theory, yes. Practically, no.

Three related ideas from the forum:
- upscale lander that fires a retro just before touchdown
- that crazy upright hovering pyramid
- a rocket with a second motor in the nose with a rearward chute

That last one could actually be pretty useful if you were going for a partially ballistic recovery, e.g. fast up fast down.

#### TRFfan

##### Well-Known Member
Not easily, because there's no aerodynamic stability at very low velocity, plus going downward your Cp is now leading Cg, unless you do something to change configuration.
You'd probably need a gimballed motor with a controller to keep the rocket upright. Ideally your main engine for landing would be a cold thruster so you would not start a fire. If you had a reservoir of gas, compressed greatly, you might be able to use it for attitude control also, which might not require a gimbal on anything.
That's what i thought but assuming you had a lot of money and experince could it be done?

#### Incongruent

##### Well-Known Member
That's what i thought but assuming you had a lot of money and experince could it be done?
Define "A lot of money"

#### TRFfan

##### Well-Known Member
Define "A lot of money"
around 2000. I'm assuming that it would be done with MPR motors (but you would need alot of stabilizing equipment).

#### rharshberger

##### Well-Known Member
around 2000. I'm assuming that it would be done with MPR motors (but you would need alot of stabilizing equipment).
$2000 is a lot of money to you, thats pretty insignificant to the cost of developing a vertical landing hobby rocket. As Steve said above the aerodynamics have their say, and a long burning, throttle-able, gimbaling motor is a must, a hybrid might work, but a liquid motor (which is outside our realm of rocketry) is the best for this application. A cold gas thruster as was mentioned might work as well, but the weight for this type of vehicle would probably make a cold gas thruster expensive (small vehicle, lots of specially made parts). Get with Jim Jarvis and George Gassaway and ask them how much they have spent on their various vertical flight (upward only) experiments, they had to develop the vehicle, the electronic controls, pretty much the only parts they used that are commercial are the motors, and commercial hobby rocket motors don't have many of the characteristics for vertical landings. #### TRFfan ##### Well-Known Member$2000 is a lot of money to you, thats pretty insignificant to the cost of developing a vertical landing hobby rocket. As Steve said above the aerodynamics have their say, and a long burning, throttle-able, gimbaling motor is a must, a hybrid might work, but a liquid motor (which is outside our realm of rocketry) is the best for this application. A cold gas thruster as was mentioned might work as well, but the weight for this type of vehicle would probably make a cold gas thruster expensive (small vehicle, lots of specially made parts). Get with Jim Jarvis and George Gassaway and ask them how much they have spent on their various vertical flight (upward only) experiments, they had to develop the vehicle, the electronic controls, pretty much the only parts they used that are commercial are the motors, and commercial hobby rocket motors don't have many of the characteristics for vertical landings.
I'm not saying that I'm going to do it, i was just asking if it could be done by someone with the nessicary funds and experience.

#### rharshberger

##### Well-Known Member
I'm not saying that I'm going to do it, i was just asking if it could be done by someone with the nessicary funds and experience.
Anything is possible with enough money sooner or later.....

As for if it could be done by any of us here, I don't know but several people are working on technologies that might be useful such as finless rockets with gimballed motors, stabilization, etc. We have some very experienced and intellegent individuals that together could do some mind blowing things.

#### TRFfan

##### Well-Known Member
Anything is possible with enough money sooner or later.....

As for if it could be done by any of us here, I don't know but several people are working on technologies that might be useful such as finless rockets with gimballed motors, stabilization, etc.
Oh ok.

We have some very experienced and intellegent individuals that together could do some mind blowing things.
I agree!

#### Steve Shannon

##### Well-Known Member
TRF Supporter
Something that might work, be less expensive, and be interesting, would be to convert the rocket to an electric drone for landing.

#### Peartree

##### Cyborg Rocketeer
Staff member
Global Mod
Dave Hein was working on his Quad Pod a few years ago and did much of what you're describing, although maybe not exactly the way that you were thinking after SpaceX did it.

[video]https://youtu.be/wUJx7LbRZn0[/video]

#### Winston

##### Lorenzo von Matterhorn
Here are some prior threads on this selected from the results found via the Google search "vertical landing ultrasonic site:rocketryforum.com" since, in my experience, the search engine here absolutely sucks. I included "ultrasonic" in that search since I've suggested in a thread the use of one of the very cheap Arduino ultrasonic ranging modules as an altitude sensor to set off a triad of, for instance, A10 BP motors as retros mounted between the rocket and its chute over an entirely non-flammable landing zone. I stole that idea from Soviet cargo drops (not what you're referring to though):

Propulsive landing with a model rocket

Powered soft landing?

The Ruskies:

#### georgegassaway

Yes, so many of you missed this. It is a link to Joe Barnard's test flying of a model to do just that. A model similar to a Falcon-9.

He has worked out a gimbaled engine for vertical flight of a finless rocket (not the first person to do so, but you have to make it work to go upwards, if you also want it to work to land under thrust too).

He is trying to fire a second motor or pair of motors for landing. Keeps having some issues, but if he sticks with it it seems he's learning enough and knows enough to probably get it to work.

His webpage:

His youtube channel trailer video:

(update note - I was mid-way writing this when I had to go shopping. By the time I posted it, Peartree posted about Dave Hein's QuadPod. Didn't realize that till after posting this message)

Now, a vertical landing under thrust is not new, and can be done simpler than what Joe is trying to do. Dave Hein has.... as far as I'm concerned, DONE IT! He used unique "barstool" type of 4-legged design with the gimbaled engine at top. It was powered by an F10 motor. The rocket weighed more than the sustainer thrust of the F10, but the F10 thrust spike was good enough to power it into the sky a few dozen feet, then slow down and begin to descend vertically under gimbaled thrust. It usually landed nose-up, legs down, but unfortunately fell over due to either bouncing, or drifting sideways due to the wind (One of the windy ones likely would have stayed upright if flown in calm and therefore not moving sideways at touchdown). So, technically it may not have stayed upright after landing, but as I said as far as I'm concerned he had soft-enough vertical landings that were under control.

Unfortunately his old web page is gone. But it *IS* mostly on the internet Archive:

The photos are not archived. Links to some photos do not work. But some others, the sites still exist. But you have to edit the links to remove the "web archive" prefix stuff, to get to the original web page's http or https.

A couple of pics from LDRS-27. Unfortunately only small previews were available, I've enlaged them:

And most if not all of the old video links work, after removing the "webarchive" prefix stuff to get to the oriignal page link

Here is video of test flight #6. You can see the thrust vectoring working.

He removed some weight from it for flight #7, to fly higher and not be thrusting for so long after landing, but it flew too high and the engine burned out long before it could land. That shows a fine line for getting the thrust to weight just right for that kind of thing, so it needed to weigh somewhere in between.

In this video of an earlier flight, the weight was about ideal. It landed just before burnout. But the wind blew it a lot to the left before landing and tumbled....ending up standing upright. Jump to 2:45 of the video.

So, it's possible. Not requiring thousands of dollars, but a lot of learning and testing and adjusting. Though the kind of testing program Joe Barnard is doing, he probably passed the $1000 mark a long time ago. But more for the equipment than the rocket hardware. And he has a, well, somewhat overkill launch pad arrangement that cost more than one would need to spend. than a model rocket. And i'm sure it cost him way more in time to design and build it than hardware/component costs. But it looks really impressive, adds realism that this is more like a "space program in miniature". And, it is FUN! So I am NOT knocking it, I REALLY LIKE it. Just indicating someone else who was trying the same thing could do the pad part for a lot less, probably using an existing pad or rail or tower. Rod is worst, Rail is 2nd best. Ideal is a tower. So a tower is the one piece of specialized ground equipment that a gimbaled rocket project could justify buying or making. OK, another update. FWIW - some pics below from my 1989 R&D project using a gimbaled engine (for the "flying *** part, nothing to do with landing). The gimbaled engine system worked nicely. But I was using "sunguidance" for the steering guidance. And that often caused problems with trying to launch vertically when the sun was always at an angle, so the engine mount was already gimbaled to one side at liftoff. Best flight it ever had was on an overcast day. So, a technical success, the gimbaling design. But as the project report's conclusion pointed out, a better type of guidance system was needed. Now, we have a lot of other great options for onboard guidance flying upwards. Off-the-shelf Model Plane autopilots like the Eagle Tree Guardian, or multicopter type controllers adapted for use. Or homemade types and custom programming such as Dave Hein did years ago an others like Joe Barnard are doing now (often with Arduinos). Last edited: #### drxcrime ##### Member Just brainstorming and seeing what anyone on here thought about this (I haven't explored the logistics of it beyond it just occurring to me): What if you had a high power rocket with an altimeter that, at apogee, deployed control surfaces (grid fins or something) at the front of the rocket and shifted the CP forward. The rocket then descends trail first at somewhat high speed and as it does so, a "return home" type control feature, combined with a "return to vertical" control feature (both exist on entry level drones and helicopters) guided it back to the launch site. then, at 700 feet, the altimeter would power on an electric ducted fan in the front of the rocket with thrust vaining connected to the same servos running the grid fins (or whatever) to slow the rocket enough to land. Good idea? Bad idea? #### solid_fuel ##### Lifetime Supporter TRF Lifetime Supporter A rocket that on ejection pushes out a quadcopter type propeller would be kind of a neat approach to this. #### solid_fuel ##### Lifetime Supporter TRF Lifetime Supporter Something that might work, be less expensive, and be interesting, would be to convert the rocket to an electric drone for landing. Damn! I stole your idea. Unknowningly at the time #### rstaff3 ##### Oddroc-eteer #### afadeev ##### Well-Known Member TRF Supporter [...]Now, a vertical landing under thrust is not new, and can be done simpler than what Joe is trying to do. Dave Hein has.... as far as I'm concerned, DONE IT! He used unique "barstool" type of 4-legged design with the gimbaled engine at top. It was powered by an F10 motor. The rocket weighed more than the sustainer thrust of the F10, but the F10 thrust spike was good enough to power it into the sky a few dozen feet, then slow down and begin to descend vertically under gimbaled thrust. [...] He removed some weight from it for flight #7, to fly higher and not be thrusting for so long after landing, but it flew too high and the engine burned out long before it could land. That shows a fine line for getting the thrust to weight just right for that kind of thing, so it needed to weigh somewhere in between. Active thrust vectoring (aka gimbaled engine) is, unfortunately, only part of the puzzle. You also need ability to throttle down the engine thrust for controlled descent, and throttle it to zero upon landing. On demand. For that you need liquid powered rocket motors, to which you can choke the flow of the propellant. That is not impossible, but gets complicated and expensive very fast. There were a few rocket hobby oriented liquid rocket motor suppliers in the past (RattWorks, AeroconCystems), but all seam to have either gone out of business, or fallen out of favor, or both. Simple solid propellant motors, that we all use, could be partially throttled by way of variable nozzle geometry, or vent ports, or pulsed rocket motor arrangement. Again, not impossible, but neither readily commercially available, nor as precise of a control as liquid powered motors. The other alternative is to sequence a bunch of solid rocket motors for a given weight of the airframe, and hope that exogenous variables (wind, propellant's thrust variance, etc), don't ruin the experiment. Which is what Dave Hein seams to have tried, as documented in the post above. a #### James Duffy ##### Well-Known Member It is worth mentioning that Joe Barnard will be presenting the Friday evening technical keynote at NARCON in a couple of weeks. It's not too late to register! www.narcon2018.org In addition to Joe's session Friday evening, four-time astronaut Scott Parazynski will be delivering the Saturday keynote. James #### Tramper Al ##### Well-Known Member Apogee offers a kit with legs that extend for an upright landing. https://www.apogeerockets.com/Rocket_Kits/Skill_Level_5_Kits/Star_Lift_Mega_Lander Nice, I was planning to look at the Mars Lander mechanism, as well as those couple of Estes models that land as a tripod - I think one has an alien head? Ideally, or course, one would want to be able to build with three of these vertical landing boosters, but I think with the Apogee kits I'd be looking at$400 for parts (a little pricey) and three composite F's (a little powerful even for my winter field, and potentially over my Level 0 certification limit).

I wonder if the parts of the Apogee model design could be scaled down a bit and built with wood for 24mm motors? (Edited because I think the Apogee legs may be wood already). Or two 18's and a 24. That would be nice.

I am guessing it's not feasible to develop and sell a Space-X model like the Falcon Heavy (though there is a version out there) without cooperation and licensing from Space-X? They are the only makers of a flying Falcon-9 model that I am aware of.

#### Steve Shannon

TRF Supporter
Nice,
I was planning to look at the Mars Lander mechanism, as well as those couple of Estes models that land as a tripod - I think one has an alien head? Ideally, or course, one would want to be able to build with three of these vertical landing boosters, but I think with the Apogee kits I'd be looking at $400 for parts (a little pricey) and three composite F's (a little powerful even for my winter field, and potentially over my Level 0 certification limit). I wonder if the plastic parts of the Apogee model design could be scaled down a bit and built with wood for 24mm motors? Or two 18's and a 24. That would be nice. I am guessing it's not feasible to develop and sell a Space-X model like the Falcon Heavy (though there is a version out there) without cooperation and licensing from Space-X? They are the only makers of a flying Falcon-9 model that I am aware of. Although it might be nice to get cooperation from SpaceX, I doubt that creating a model of one of their rockets requires any kind of licensing. Thats not the market theyre concentrating on. Steve Shannon #### rstaff3 ##### Oddroc-eteer Although it might be nice to get cooperation from SpaceX, I doubt that creating a model of one of their rockets requires any kind of licensing. That&#8217;s not the market they&#8217;re concentrating on. Steve Shannon The plastic model industry has had licensing issues with military planes. So, if you didn't get official permission from SpaceX, you'd risk legal repercussions. Would SpaceX care? I kind of doubt it as all their images are public domain. #### afadeev ##### Well-Known Member TRF Supporter The plastic model industry has had licensing issues with military planes. So, if you didn't get official permission from SpaceX, you'd risk legal repercussions. Would SpaceX care? I kind of doubt it as all their images are public domain. There is nothing unique about SpaceX's one core + two boosters configurations. They are neither the first, nor the last, to use that arrangement. You no more need to license it from them than they did from Ariane 5, or the others. You can grab any 3 tubes + nose cones + motor mounts, attach them together (permanently, or with an option to separate), paint it white and let it fly. Call in FalconHeavy, or rstaff3Heavy, or TramperHeavy, Big Mamma, it will still fly the same. Your challenge will be not in the naming rights, but in moving the CP below CG, to keep the rocket flying straight and up off the launch rod. Model rockets accomplish that by hanging big fins on the tail end of the tubes. Commercial rockets, like FH, accomplish the same by vectoring the motor thrust. Do you have the budget for that? If not, forget about licensing issues, as your final product will, at best, bear a spiritual homage to FH. I was planning to look at the Mars Lander mechanism, as well as those couple of Estes models that land as a tripod - I think one has an alien head? Ideally, or course, one would want to be able to build with three of these vertical landing boosters, but I think with the Apogee kits I'd be looking at$400 for parts (a little pricey) and three composite F's (a little powerful even for my winter field, and potentially over my Level 0 certification limit).
I would guess that \$400 is just the cover charge for opening the thrust vectoring can of warms.
If the prospect of a four figure investment gives you a pause, this project may not be right for you...

a

#### Stan

##### Well-Known Member
I have a super alpha 3 that has landed upright 3 out of the last 5 launches. * foot ong elastic shock cord stabilizes it well.