Feasibility of pen-sized missiles?

  • Thread starter Thread starter petergreat
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the feasibility of creating a pen-sized missile capable of hitting a target, such as a street lamp, from a distance of 200 meters. Participants explore various engineering aspects including aerodynamics, control systems, and propulsion methods, while emphasizing the academic nature of the inquiry.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant proposes the idea of using advanced control surfaces to achieve flight stability, suggesting that thrust vectoring could be effective at small scales.
  • Another participant expresses skepticism about the practicality of a pen-sized missile, arguing that the size would limit control and propulsion efficiency.
  • There are suggestions to replace the infrared imaging camera with a simpler infrared receiver that could work with an IR laser for targeting, although this approach raises concerns about accuracy at 200 meters.
  • A participant mentions that while insects can reach targets effectively, the technology to replicate such efficiency in a missile form does not currently exist.
  • Concerns are raised about the limitations of using bottle rockets as propulsion, with one participant noting their typical range and weight limitations.
  • Humorous remarks are made about the nature of insects as homing missiles, highlighting the contrast between biological and mechanical systems.

Areas of Agreement / Disagreement

Participants express a range of opinions, with some believing the concept is possible under certain conditions, while others firmly state it is impractical or impossible. There is no consensus on the feasibility of the project.

Contextual Notes

Participants note limitations related to size, control mechanisms, and propulsion methods, which remain unresolved and may impact the overall feasibility of the proposed missile.

petergreat
Messages
266
Reaction score
4
I'm fancying whether it's possible to build a pen-sized toy missile which could, for example, hit a street lamp at night from within 200m, just as a proof-of-concept. I would like the missile to have an infrared imaging camera, and a low-cost programmable micro-processor which analyzes the image and issues signals to the fins to adjust the flight path. Gun powders as rocket propellant would be quite adequate for my desired range. I'm not interested in doing any damage (and certainly want to re-use the missile), so the mini missile doesn't need to carry any "warhead".

Based on your knowledge about engineering (aerodynamics, infrared imaging, microelectronics etc), do you think it's possible to build such a small device within reasonable cost for amateurs? Thanks for contributing your opinion.

Clarification: Please do not delete the thread as "dangerous activity". The motivation is entirely academic.
 
Last edited:
Physics news on Phys.org
petergreat said:
I'm fancying whether it's possible to build a pen-sized toy missile which could, for example, hit a street lamp at night from within 200m, just as a proof-of-concept. I would like the missile to have an infrared imaging camera, and a low-cost programmable micro-processor which analyzes the image and issues signals to the fins to adjust the flight path. Gun powders as rocket propellant would be quite adequate for my desired range. I'm not interested in doing any damage (and certainly want to re-use the missile), so the mini missile doesn't need to carry any "warhead".

Based on your knowledge about engineering (aerodynamics, infrared imaging, microelectronics etc), do you think it's possible to build such a small device within reasonable cost for amateurs? Thanks for contributing your opinion.

Sure. But why?
 
Initially my thought was a resounding no, but then I got to thinking. From an aero side, I think if you used advanced control surfaces, you have a chance. Firstly, at that size and distance, we're talking rockets. For controling, you could use 3 tabs evenly located around the circumference of the nozzle. Depending on their depth into the flow, this has been shown to be able to vector thrust quite well.

You won't be able to maneuver well, but as long as you aimed resonably well, you'd be alright. My thought to this approach is that having moving control surfaces, e.g. wings, fins, canards would be too bulky to have implemented. Somethings got to move em.

Aside from that, I'd be interested to know the size limitations enforced by the electronics. That's quite out of my area.
 
possible: maybe
reasonable cost: no

The pen size is going to be the problem. Maybe if it was a fat magic marker or something, but your typical Bic is just too small to be able to control economically. instead of using an infrared imaging camera, you could possibly reduce size by using a simple ir receiver and use your launching system to "paint" the target with an ir laser. The ir receiver could then potentially pick up this signal and control from there, but at 200m, that could be tricky.

200m is also pretty far for a pen size amount of gun powder to propel unless it was launched like a bullet from a barrel.

I'm going to go for a total NO answer at the moment.
 
Many insects will get to the target without problem... so while we don't have technology as of now, task seems to be in the range of some biomechanical system.
 
Bottle rockets are reasonably efficient motors and are about the size of a motor one could fit into a pen-sized body. How far can a bottle rocket go? Not much more than a hundred feet or so, in my experience; and that's ONLY propelling its own weight. Impractical, if not a practical impossibility, I say.
 
Borek said:
Many insects will get to the target without problem...

Unless they can do it by farting flaming gas, I'm going to have to say that's not a missile.
 
Have you been ever attacked by a bee that thinks you got too close to beehive? It is not just a missile, it is a homing missile :wink:
 

Similar threads

Kerbal Space Program - Rocket Design Basics
  • · Replies 2 ·
Replies
2
Views
10K
Do Movies Teach Us Realistic Life Skills?
  • · Replies 1 ·
Replies
1
Views
10K
Graduate Hydrogen-Boron Plasma Toroid Fusion
  • · Replies 4 ·
Replies
4
Views
7K
Graduate Hydrogen-boron High Density Plasma Toroid Fusion
  • · Replies 3 ·
Replies
3
Views
4K