h a l f b a k e r yYou gonna finish that?
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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.
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]
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Annotation:
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//birds// Strictly ballistic projectiles. No aerodynamic
lift mechanisms. |
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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. |
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Weight to altitude ratio would be one category. |
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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. |
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//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. |
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I was (not very clearly) referring to the Lofstrom
Loop wotsit (link). |
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NB No cakes or doughnuts on the loop please,
apparently "The launch loop may be damaged by
wind, lightning, and icing". |
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PS And that big whip idea to zoom stuff way high
into the sky. |
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Ah. I was thinking more of a project for the Boy Scouts. |
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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. |
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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? |
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Maybe it should be height of the rocket compared to height
of the
apogee. |
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Foot tall rocket gets to 100 feet beats two foot tall rocket
that gets to the same height. |
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Then you could get rid of those 100 foot tall rockets that
only get a foot off the ground and reach 101 feet. |
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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) |
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I think this is baked as Punkin Chunkin (link) though for ease
of measurement they go horizontally instead of vertical. Same
basic means though. |
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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? |
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//I think this is baked as Punkin Chunkin// |
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//doesn't ANY balloon win this competition?// |
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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. |
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You lost me at "Non Pyrotechnic " |
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// 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.// |
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As soon as they quit giving my lotto winnings to other people, you got it. |
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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. |
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If I thought it up, then that means that somebody else smarter than me already thought it up a long time ago. |
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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. |
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It just can't be on fire. |
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This lends itself to school projects and the like. |
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// Maybe it should be height of the rocket compared to
height of the apogee. // |
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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? |
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// It just can't be on fire. // |
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So boiling cryogenic liquids are fine? |
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This is clearly an application demanding a supergiant trebuchet ... |
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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. |
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not sure how scammy this is, but if you check latest link --
thought it funny they talk about "rocketless launches' and
thus linked it |
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// maybe you need to specify […] that all chemical
components and outputs must be non-harmful. // |
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All chemical components and outputs are harmful, including
water. The dose makes the poison. |
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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). |
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I did find some HyperSciences patents [link], though fewer
than they claim in their pitch deck, which might be
interesting to look through. |
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// It just can't be on fire// So, your ordinary nuclear
rocket would be OK? |
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//So boiling cryogenic liquids are fine?// |
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Mmmm, getting a little dangerous for the kiddies. |
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OK, no fire, or potentially harmful agents. |
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As the next post suggested. Base/acid reaction stuff
is ok as long as they're not harmful. |
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//So, your ordinary nuclear rocket would be OK?// |
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As long as it's the kind that's safe for kids to play
with. |
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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. |
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Oh wait, eye injuries.OK, mandatory eye protection. |
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//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. |
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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. |
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Yea, that just occurred to me. These are basically
eye gougers. |
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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. |
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That being said, it was more thrilling than any roller
coaster I've been on. |
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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. |
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// OK, no fire, or potentially harmful agents. // |
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Everything is a "potentially harmful agent". The use makes
the weapon? |
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// As the next post suggested. Base/acid reaction stuff is ok
as long as they're not harmful. // |
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The reaction of vinegar and baking soda releases carbon
dioxide, which is not only a greenhouse gas but also an
asphyxiant. |
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Well, no wearing plastic bags over the head and
filling it with rocket exhaust gas then. |
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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". |
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As long as they're making money the environment
will be
fine. |
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So it's okay if I enter a rocket propelled by boiling carbon
dioxide or tetrafluoroethane (canned air), then? |
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As long as you pay your indulgen... I mean... carbon
credits, yes. |
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Okay, so if no balloons, then I'll go with a rail gun. |
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Gotta be self contained, no external launch mechanisms. |
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I'll change the title to Non Pyrotechnic Rocket Challenge".
Current title's confusing. |
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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. |
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I think the slingshot idea's been proposed before though.
Rings a bell. |
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//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.// |
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Not if you use a nuclear pile to heat the air |
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//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.// |
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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). |
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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. |
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//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.// |
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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. |
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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? |
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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) |
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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. |
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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. |
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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. |
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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. |
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//It's sort of a jet/ramjet/scramjet/rocket all in one and
it's very neat.// |
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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. |
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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. |
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//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. |
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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. |
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As far as the eye damage problem, soft foam rockets and
eye protection. |
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And tell them not to be stupid. |
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OK, here's my entry. (link) |
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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. |
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Then all you've got is cardboard, springs and ribbon. Easy. |
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