Half a croissant, on a plate, with a sign in front of it saying '50c'
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Non Pyrotechnic Rocket "Space Launch" Challenge

Not getting to space with this obviously, but winner is the one who gets the closest.
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No fire allowed. You can use rubber bands, compressed air, springs etc. The idea is to have the biggest, most powerful first stage possible and the smallest, lightest final stage. Highest altitude reached wins.

So my entry might be a 100 pound spring that launches a first stage then a 50 pound spring that in turn launches a 25 pound spring loaded second stage and then a series of subsequent stages into the air.

The last stage might be a toothpick blown out of a compressed air gun, perhaps trailing a radar reflective ribbon so it could be tracked.

To keep things real, the entire entry might have a weight limit of say... 1,000 pounds? You could also have weight categories as well.

My guess is you'd start with springs and end with compressed air but there in lies the challenge. Highest design wins.

Fun school project to get kids interested in something other than selfies perhaps.

doctorremulac3, Feb 25 2019

This one's clever. https://www.scienti...age-balloon-rocket/
Not really a rocket, more of a monorail, but still, very simple which is cool. [doctorremulac3, Feb 25 2019]

Here's your off-the-shelf stuff. https://waterockets...eme-3-stage-rocket/
Compressed air water rocket with 3 stages. (I want one) [doctorremulac3, Feb 25 2019]

Here we go. http://www.aircomma...s.com/polaronG2.htm
[doctorremulac3, Feb 25 2019]

Lofstrom Loop https://space.nss.o...Nowicki/SPBI116.HTM
[not_morrison_rm, Feb 25 2019]

Wikipedia article on the above https://en.wikipedia.org/wiki/Launch_loop
[notexactly, Feb 25 2019]

Wikipedia article on // that big whip idea to zoom stuff way high into the sky // https://en.wikipedi...Skyhook_(structure)
[notexactly, Feb 25 2019]

Punkin Chunkin https://www.punkinchunkin.com/
Horizontal version of idea [MisterQED, Feb 26 2019]

if you want to invest in it https://www.seedinv....inc/series.a/about
rocketless launches [theircompetitor, Feb 27 2019]

HyperSciences patents https://patents.goo...om/?q=hypersciences
Mentioned in my anno. Patents belonging to the company seeking investment in the previous link [notexactly, Feb 27 2019]

Sprint loaded rocket launcher project. (but not a spring loaded rocket) https://www.youtube...watch?v=v0MZRZT8BKI
Laugh now at these nurdy little kids, you might be working at a company one of them started some day. [doctorremulac3, Mar 02 2019]

Some spring stuff https://www.youtube...watch?v=4V08J3joavk
[doctorremulac3, Mar 02 2019]

Three stage sprocket. (spring powered rocket) https://www.dropbox...D%20ROCKET.png?dl=0
Has this ever been done before? Where's my Nobel prize? [doctorremulac3, Mar 02 2019]

[link]






       birds
pocmloc, Feb 25 2019
  

       //birds// Strictly ballistic projectiles. No aerodynamic lift mechanisms.   

       Addendum: One thing you could rank is weight to altitude, points being given for lightness. So a 2 pound rocket going to 1,000 feet would loose over a 1 pound rocket going 900 feet.   

       Weight to altitude ratio would be one category.   

       But you'd also want to have the straight altitude competition. If somebody brought in a 3 story tall rubber band powered affair I'd pay to see that. From an underground bunker that is.
doctorremulac3, Feb 25 2019
  

       One of them loop things.
not_morrison_rm, Feb 25 2019
  

       ?
doctorremulac3, Feb 25 2019
  

       //No aerodynamic lift mechanisms.//
You only said "no fire". Using wings to get altitude doesn't need fire, and is a viable method to get part-way to space. Rockets aren't "strictly ballistic" either.
The other obvious method is electromagnetism. Linear EM launcher, railgun, that sort of thing.
neutrinos_shadow, Feb 25 2019
  

       //?   

       I was (not very clearly) referring to the Lofstrom Loop wotsit (link).   

       NB No cakes or doughnuts on the loop please, apparently "The launch loop may be damaged by wind, lightning, and icing".   

       PS And that big whip idea to zoom stuff way high into the sky.
not_morrison_rm, Feb 25 2019
  

       Ah. I was thinking more of a project for the Boy Scouts.   

       Or the Y Indian Guides that I was a member of. (Kids from the wrong side of the tracks too poor to join the Boy Scouts.) We'd dress like Indians and learn Indian stuff. I can make an arrowhead for instance.
doctorremulac3, Feb 25 2019
  

       Winning by having the lightest projectile seems to run counter to competitiveness: lighter projectiles are easier to launch. Don't you want to give more points for doing something more difficult?
notexactly, Feb 25 2019
  

       Maybe it should be height of the rocket compared to height of the apogee.   

       Foot tall rocket gets to 100 feet beats two foot tall rocket that gets to the same height.   

       Then you could get rid of those 100 foot tall rockets that only get a foot off the ground and reach 101 feet.
doctorremulac3, Feb 26 2019
  

       Assuming an arid launch area, supporting array of microwave ovens tracking the missile a little more umph. Or possibly substitute dry cleaning fluid for water? (typed on tiny smart phone)
not_morrison_rm, Feb 26 2019
  

       I think this is baked as Punkin Chunkin (link) though for ease of measurement they go horizontally instead of vertical. Same basic means though.
MisterQED, Feb 26 2019
  

       Wait, instead of previous entry, doesn't ANY balloon win this competition? Weight = small or negative depending on how you measure and then maybe as a second stage you use the pressure of the balloon to shoot a spit ball up another couple feet?
MisterQED, Feb 26 2019
  

       //I think this is baked as Punkin Chunkin//   

       //doesn't ANY balloon win this competition?//   

       No external force can be used to launch. All lift mechanisms have to be non aerodynamic, reaction based and contained within the rocket which must be heavier than air.
doctorremulac3, Feb 26 2019
  

       You lost me at "Non Pyrotechnic "
Voice, Feb 27 2019
  

       // No external force can be used to launch. All lift mechanisms have to be non aerodynamic, reaction based and contained within the rocket which must be heavier than air.//   

       So... you want UFO.   

       Sure.
doctorremulac3, Feb 27 2019
  

       As soon as they quit giving my lotto winnings to other people, you got it.   

       It's kind of the opposite of anti-gravity, it's more... pro-inertia with select points of least resistance but, the effect will be the same.   

       If I thought it up, then that means that somebody else smarter than me already thought it up a long time ago.   

       No, not that complicated, you can have lots of reaction mass based flying things by just shooting stuff out of it so it moves in the other direction.   

       It just can't be on fire.   

       This lends itself to school projects and the like.
doctorremulac3, Feb 27 2019
  

       // Maybe it should be height of the rocket compared to height of the apogee. //   

       I like that. However, if my rocket starts out 0.5 m tall and extends to 1.5 m as it launches, what measurement is used? What if it collapses back to 0.5 m before landing?   

       // It just can't be on fire. //   

       So boiling cryogenic liquids are fine?
notexactly, Feb 27 2019
  

       This is clearly an application demanding a supergiant trebuchet ...
8th of 7, Feb 27 2019
  

       Are non-flaming chemical reactions allowed? The obvious example to get a positive response would be baking soda and vinegar, though I'm sure some of the chemists here could find a more potent option. I'm guessing H2O2 isn't what you had it mind, so maybe you need to specify the maximum exhaust gas temperature (49 C maybe), and that all chemical components and outputs must be non-harmful. You might also want to specify a maximum internal pressure for tanks and reaction chambers.
scad mientist, Feb 27 2019
  

       not sure how scammy this is, but if you check latest link -- thought it funny they talk about "rocketless launches' and thus linked it
theircompetitor, Feb 27 2019
  

       // maybe you need to specify […] that all chemical components and outputs must be non-harmful. //   

       All chemical components and outputs are harmful, including water. The dose makes the poison.
notexactly, Feb 27 2019
  

       Re the HyperSciences link: The risks section says one of the guys involved is also involved in a couple of other companies, EnergeticX (which has no Google results) and its subsidiary Pipeline 2 Space (whose website seems to have been replaced by a "better than Tinder - are you looking for sex tonight in your area?" ad).   

       I did find some HyperSciences patents [link], though fewer than they claim in their pitch deck, which might be interesting to look through.
notexactly, Feb 27 2019
  

       // It just can't be on fire// So, your ordinary nuclear rocket would be OK?
MaxwellBuchanan, Feb 27 2019
  

       //So boiling cryogenic liquids are fine?//   

       Mmmm, getting a little dangerous for the kiddies.   

       OK, no fire, or potentially harmful agents.   

       As the next post suggested. Base/acid reaction stuff is ok as long as they're not harmful.   

       //So, your ordinary nuclear rocket would be OK?//   

       As long as it's the kind that's safe for kids to play with.   

       I'd like to suggest this to a elementary school. Kids get to learn a little bit about something other than cultural indoctrination and then get out in the fresh air.   

       Oh wait, eye injuries.OK, mandatory eye protection.
doctorremulac3, Feb 28 2019
  

       //OK, no fire, or potentially harmful agents.// A big pointy thing designed to be flung skywards by a 12ft rubber band is basically a speargun.   

       Kids should be exposed to more danger, not less. We have created a generation that has no idea whatsoever how to interact with the real world.
MaxwellBuchanan, Feb 28 2019
  

       Yea, that just occurred to me. These are basically eye gougers.   

       Enthusiastic agreement with your point. That being said, there's a happy medium. I was driving (illegally) at 13 (in my defense I was a very safe driver) and doing other incredibly stupid stuff in my teens. One night during a raging storm, me and a buddy threw two pool rafts off a drainage culvert into a raging, storm swollen creek, ran to the other side and tried to jump on them. We missed of course and after swimming to catch them, took a wild ride down to the bay. I learned two valuable lessons: 1- I was lucky, and 2- I was a dumbass.   

       That being said, it was more thrilling than any roller coaster I've been on.   

       Then there was the explody stuff. Nothing really illegal, just incredibly stupid and dangerous. Lots of blowing things up with M80s, making neat "fire sculptures" with my friend's dad's smokeless powder and shotgun shell primers, including one instance where I was temporarily blinded after trying to re- create the Wile E Coyote trick of making a big line of gunpowder leading to a big pile of gunpowder or filling a jar with primers, gunpowder and flammable glue on top as a fuse. Good times.
doctorremulac3, Feb 28 2019
  

       // OK, no fire, or potentially harmful agents. //   

       Everything is a "potentially harmful agent". The use makes the weapon?   

       // As the next post suggested. Base/acid reaction stuff is ok as long as they're not harmful. //   

       The reaction of vinegar and baking soda releases carbon dioxide, which is not only a greenhouse gas but also an asphyxiant.
notexactly, Feb 28 2019
  

       Well, no wearing plastic bags over the head and filling it with rocket exhaust gas then.   

       As far as the global warming greenhouse gas, we'll send a dollar to the DNC for each CO2 producing rocket built to purchase those indulgences they sell, excuse me, "carbon credits".   

       As long as they're making money the environment will be fine.
doctorremulac3, Feb 28 2019
  

       So it's okay if I enter a rocket propelled by boiling carbon dioxide or tetrafluoroethane (canned air), then?
notexactly, Feb 28 2019
  

       As long as you pay your indulgen... I mean... carbon credits, yes.
doctorremulac3, Feb 28 2019
  

       Okay, so if no balloons, then I'll go with a rail gun.
MisterQED, Mar 01 2019
  

       Gotta be self contained, no external launch mechanisms.   

       I'll change the title to Non Pyrotechnic Rocket Challenge". Current title's confusing.
doctorremulac3, Mar 01 2019
  

       One of my favorite thought experiments is a really heavy propeller-craft spun up in a vacuum. Once the vacuum silo is opened it shoots upwards and enters orbit under momentum alone, the remaining rotational inertia is dumped by splitting the propeller craft in two to create two counter-orbiting satellites.
bigsleep, Mar 02 2019
  

       Dhunno, grabbing air by any method and throwing it backwards isn't going to give you the push you need to go 7 thousand miles an hour plus depending on your orbit. Jets don't even do that much less propellers. By the time you take in the oxygen to burn the fuel you've had to absorb so much friction to get it in there it's just much easier to carry a tank of the liquefied stuff in a nice, fully self contained streamlined container.   

       I think the slingshot idea's been proposed before though. Rings a bell.
doctorremulac3, Mar 02 2019
  

       //By the time you take in the oxygen to burn the fuel you've had to absorb so much friction to get it in there it's just much easier to carry a tank of the liquefied stuff in a nice, fully self contained streamlined container.//   

       Not if you use a nuclear pile to heat the air
Voice, Mar 02 2019
  

       //100 pound spring that launches a first stage then a 50 pound spring that in turn launches a 25 pound spring loaded second stage and then a series of subsequent stages into the air.//   

       Staging is only really worthwhile if you have a decent specific impulse (= oomph) in each stage. If you're using things like springs or elastic bands, which have very very very low oomphs, you'll be better off with a single stage - in effect a giant catapult where all the mass stays on the ground, and the projectile itself is passive and fairly lightweight (not too lightweight, as it has to be have a good amount of kinetic energy when launched).   

       You might want to consider something like a hugely huge crossbow, pointing upwards. With some cunning design, there's no reason you couldn't get your projectile up to a mach or two as it leaves the launcher.
MaxwellBuchanan, Mar 02 2019
  

       //By the time you take in the oxygen to burn the fuel you've had to absorb so much friction to get it in there it's just much easier to carry a tank of the liquefied stuff in a nice, fully self contained streamlined container.//   

       You should look at Reaction Engines. The have an engine which will air-breathe efficiently up to some stupidly high mach number; it cools the incoming air by several hundred degrees in a few milliseconds. Then, when air runs out, it can switch over to using onboard oxygen. It's sort of a jet/ramjet/scramjet/rocket all in one and it's very neat.
MaxwellBuchanan, Mar 02 2019
  

       Well, with the multi stage spring thing, you're going to need a lot of mass in each lower stage to get anything to push against for the next stage so not sure how well that would work. 500 pound spring equipped first stage might get to say... 100 feet? Then a 250 pound spring equipped to another 100, 125 another, 75 etc. Maybe 700, 800 feet?   

       Actually let's work backwards using a bow and arrow as the final stage. Mr Internet says an arrow shot up into the air can reach 150 feet so pretty safe to say you could expect that with every stage multiplying the weight as necessary for every lower part of the "sprocket" (spring rocket... new word)   

       Somebody who knew math could just analyze that bow and find out how big the spring loaded version would have to be at that first stage to get reach space. Several hundred stories high I expect.   

       My guess is you'd need a 1,760 stage sprocket to reach the 50 mile up edge of the Earth's atmosphere and officially achieve space. If the top stage was that bow and arrow affair, call it... 5 feet tall and flew to 30 times its height, 150 feet and the stage below it had to be twice that height and weight so 10 feet tall to go 300 feet, 20 feet tall for 600 feet, but that mass is wrong, I don't think you'd get a straight line between size of the launcher and height it would achieve.   

       So I'll just guess that to have a sprocket that would reach the 50 mile apogee necessary to call it a space vehicle, it would have to be... I'm going with... one mile tall, assuming each stage was nestled within the previous stage.   

       Now the numbers might be off, but I know you can reach space with a sprocket if you've got the resources because a 25 mile tall rocket could easily reach double its height and leave the atmosphere. Now you work backwards from there and try to make a more practical version with multiple stages.
doctorremulac3, Mar 02 2019
  

       //It's sort of a jet/ramjet/scramjet/rocket all in one and it's very neat.//   

       Oh yea, to get up out of most of the atmosphere I think these scramjets or other air breathing engines are a great way to go for the initial stage, but if you're talking about doing all the work you need to do most of your acceleration outside that atmosphere that turns into a brick wall above mach 6 or so.   

       I also had an idea for a pure turbojet first stage. I'll tack that up on the target board and see if it gets any hits.
doctorremulac3, Mar 02 2019
  

       //a 25 mile tall rocket could easily reach double its height and leave the atmosphere// Given enough initial velocity, anything can leave the atmosphere. But my point is that if you want a launch Mass X with the lowest possible Mass P of propellant (which equates to springs in your case), the optimal balance between stages depends heavily on specific impulse (oomph). For very very low SIs, the most efficient number of stages is less than two.
MaxwellBuchanan, Mar 02 2019
  

       Wonder if this should just be simplified to a sprocket, spring loaded rocket competition. It's the easiest rocket to make. It also frames the real simplified fundamentals like you referred to. I think using springs you could basically teach little kids rocket science in a way that was fun.   

       As far as the eye damage problem, soft foam rockets and eye protection.   

       And tell them not to be stupid.
doctorremulac3, Mar 02 2019
  

       OK, here's my entry. (link)
doctorremulac3, Mar 02 2019
  

       Annotation to the linked design: Rather than having a complicated motor pulling strings that pull pins to release the springs mechanism, you have ribbons holding in spring mounted pins that hold the next stage springs in place. When a spring ejects from one stage, it exposes a ribbon that was tightly wound around the base of the next stage such that it was holding spring loaded pins in place. When the ribbon unwinds, it releases pressure on the pins allowing them to pop out and release the spring for the next stage. Don't feel like drawing it, take my word for it.   

       Then all you've got is cardboard, springs and ribbon. Easy.
doctorremulac3, Mar 02 2019
  
      
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