How to Build a Rocket Engine in Your Kitchen (Experiment Episode)
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How to Build a Rocket Engine in Your Kitchen (Experiment Episode)

January 17, 2020

[♪INTRO] If you’ve ever taken a science class, you’ve
probably done some kind of at-home biology, chemistry, or physics experiment. And for good reason — a baking soda volcano
is an easy way to get a hands-on look at how the world works. Plus you get to make a mess—tons of foam,
red food coloring… your mom is like, “Why?” But when it comes to understanding space,
at-home experiments are a lot harder. After all, space is a giant vacuum, which
you can’t exactly recreate in your basement. And even if you could, you shouldn’t. One thing you can build at home, though, is
a rocket. Specifically, a hybrid rocket engine, which
many engineers want to use to explore the solar system. All it takes are some basic household supplies
and a little caution. All rockets work by throwing something out
the back to propel the rocket forward, and hybrid rockets are no exception. Like what we use in current rockets, they’re
a type of chemical engine, and the big ones generate force with a giant, controlled explosion. We’ll do our best to make sure this experiment
doesn’t get all explode-y, but we will create a smaller flame. And like with a full-sized rocket, we’ll
make that fire using two basic components: fuel and an oxidizer. The fuel is whatever you’re burning to propel
your spacecraft forward, and the oxidizer helps your fuel catch on fire. Like the name suggests, this is often an oxygen-containing
compound. Current rocket engines will sometimes combine
these elements in one solid, pre-mixed block — that’s a solid engine. Or, they might use liquid engines, which have
separate liquid components that get mixed as they go. Hybrid engines are special because they use
a combination of both solid fuel and liquid or gas oxidizer. Right now, these engines tend to have less
thrust than the other models, so they haven’t been used on many missions. A lot of those limitations have to do with
how the fuel burns … which is what you’re about to see for yourself. So, we don’t have a lab or a kitchen in
this room, but we do on SciShow Kids, so I’m going to go over to the SciShow Kids studio
next door for a little bit of rocket science. For our hybrid rocket, we’re going to use
some cylindrical fuel — this is a pasta noodle, it’s rigatoni, it’s got calories
in it. You burn it to make yourself. We’re going to burn it to make a rocket. And for our oxidizer, we’re going to be
using pure oxygen gas, which will be created through a reaction between hydrogen peroxide
and active yeast. The yeast contains a protein called catalase,
which will break down the hydrogen peroxide into water and pure O2 gas. Besides the pasta, hydrogen peroxide, and
yeast, you’ll also need a few other basic staples: some safety goggles, a fire extinguisher
just in case, and a lighter or a few matches, and a small mason jar with a hole knocked
in the lid. Our jar is about 230 milliliters, or 8 fluid
ounces, and the hole in the top is around a third of a centimeter across. The important part is that the noodle should
fit over the hole without covering any of the hole up, and without any of the hole escaping
from around the noodle. First, lay out all of your supplies ahead
of time so you’re ready to go once the reaction starts. Then, you fill your mason jar about three-quarters
of the way with hydrogen peroxide — or about 175 milliliters. Now, here comes the fun part. Add a quarter of a teaspoon of yeast to your
jar, and stir. You should see some bubbles start to form
— that’s the pure oxygen. Quickly place the lid on the jar, and place
the noodle upright over the hole. Then — get ready for it — light the top
of the noodle on fire! You should see a small column of flame rise
up over the noodle as it burns. There is your engine! That’s a pretty good engine! Oooh! There, it’s going! Oh my gosh. Now it isn’t producing much force, and any
force it is making is directed into the table. So the engine won’t go anywhere, which is
probably a good thing in this case given that—ah, large sizable chunk of it is on fire. The reaction’s either going to continue
until the noodle is all burned up, or until the chemical reaction with the yeast stops. We’re going to have to wait until that gets
a little less hot. The main limitation with hybrid rocket engines
is that they just aren’t very powerful compared to other rocket types. And a lot of that is because of how the fuel
burns. In our demo, the oxidizer flowed through the
rigatoni-fuel, and it’s basically the same process in the real thing. How fast the fuel burns — and how much thrust
the engine produces — has to do with how much oxidizer is moving through it. If the oxidizer has just one hole to flow
through, like with our noodle, it will only burn a little fuel at a time, so it won’t
be very powerful. The big challenge for engineers is figuring
out how to shape the fuel so there’s an optimal flow — enough so that it can propel
a rocket efficiently, but not so much that it burns through all the fuel all at once,
which would just be an explosion. Teams are working on it, though! There’s been more interest in developing
hybrid rockets over the last few years. And another cool thing about this demo, besides
the column of fire, is that it kind of illustrates why. One advantage to this type of engine is that
it’s hard to accidentally blow up. Not that I’m encouraging you to try. But since the fuel and oxidizer are stored
separately, there’s a much lower risk of accidental explosion compared to a solid engine,
where everything is already blended together. In these solid mixtures, the block can sometimes
become damaged, which can lead to uneven firing. And hybrid engines are less complicated than
many liquid engines, since hybrids only have one fluid component instead of two. For our rocket, we didn’t have to worry
about continuously mixing fluids and hitting the right ratios and flow rates. There were fewer moving parts. In the real world, these benefits translate
to engines that could help us launch rockets more safely and more cheaply than we are right
now. We just have to figure out how to give them
some extra thrust. Unfortunately, that probably isn’t a problem
we can solve with pasta and mason jars, so we’ll have to leave it to the experts. Thanks for watching this episode of SciShow! If you’d like to keep learning more about
space, we have a channel where we unpack all kinds of mysteries about our universe — and
the rockets that help us explore it. You can learn more at [♪OUTRO]

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  1. I have a question for everyone in the comments who knows a lot about biology, I’m going into my señor year and want to have a bio project that involves generational breeding of aphids. Do you think 1 year is enough time to make the project results worth while. It’s about diet change and behavioral response

  2. The problem with using a kitchen scale to measure the thrust in this experiment as some have suggested is that the thrust force on the scale would be canceled out by the mass loss from the burning of the fuel and the release of the O2 from the peroxide.

  3. Funny how this displays still ads while almost all similar videos from other channels can't as they are "not advertiser friendly". Oh I forgot, you have 5mio subscribers.

  4. Man all that money I spent on Estes and other brand engines and I could have been using Pasta instead.

  5. For anyine wondering whats the deal with Hank and Elon Musk, it went something like this:
    Hank: You can agree with Elon that he is a job creator and also agree that he shouldn't have clapped back to a stranger in anger when he is a billionaire with millions of very passionate followers.
    Elon: I think the person who attacked me on Twitter will survive somehow
    Hank: Oof sad emoji face
    Thats all, people in this comment section are blowing it up out of proportions.

  6. Next you add the beryllium and thorium then mix with an anhydrous alcohol such as pentene and hover it through the vacuum cleaner make // make shift turbo pump mix a little LiO through another vacuum and Bush bash bosh you have a make shift jetpack

  7. Do this on a force plate! (weight scale) to see how much thrust it actually does generate! I'm curious now….

  8. My mom does not say why, she brings the mop to my face, beats me with it and then forces me to clean the mess I made.

  9. Not to be a pedant, but that's not how hybrid rockets work. Hybrids work by melting/entraining/subliming the fuel as the oxidizer is moving past, and combusting the two. The combustion moves from the center of the fuel grain out. This experiment basically just set a noodle on fire in an oxygen-rich environment.

  10. This is one of those channels that I straight like even before I’ve seen the video, because it’s a guarantee that it’ll be good.

  11. Okay this just gave me a terrible idea. Put the hydrogen-peroxide and yeast in a potato cannon close it off, let pressure build up for a bit. Put powdered sugar or flour in the barrel and fire at a flame.

    Don't do this, this is a very bad idea.

  12. explanation is good but your rocket example is bad very unrelated you should used sugar and stump remover

  13. I'm sure happy I learned volcanoes are full of baking soda and vinegar.

    and that's in no way a rocket engine, you're just burning a noodle.

  14. I feel like maybe a drop or two of liquid dish soap would have been beneficial, to prevent the liquid from potentially shooting through the hole. Too much of the peroxide or yeast might end up with the noodle or the floor wet.

  15. Before doing this, try the noodle on the jar with the hole, but without the hydrogen peroxide and yeast. Then you can see if there's a difference between a burning noodle and this.

  16. The shape of the solid component's molecule should be the big influence on the structure. Making the attachment point for the oxidizer readily available would be key.

  17. You can also make a pulse jet with a mason jar by putting a small amount of pretty volatile fuel in it (I used methanol), poking a hole in the top, and lighting it. Very noisy and more exciting but not nearly as safe, especially since it tends to break, which, you know, spills hot jet fuel near a flame. It helps to put it in a pool of water though. Advice to anyone who wants to try this, it's important to get the hole in the top as round as possible. You can probably find pictures where people suspend a metal tube inside the jar but I've never tried it.

  18. I feel that the most appropriate way to do this is with a Ball mason jar, since they also make real rockets.

  19. When theuy say: pure oxigen is highly reacting, what does it react with? for example would pure oxigen explode or burn if in contact with a flame? What the chemical reaction happening in the explosion?

  20. When I saw this exact same experiment on another, more obscure, youtube channel I did think it was cool and I later saw an eposide of myth busters (first one on netflix) where they made a bigger one out of candle wax but it wasn't until watching this video with all the extra explanation that I had the idea to see if I can combine the two and drill out a candle on top of a jar with perhaps some battery acid as the catalyst (would love to get my hands on a medical oxygen condenser)
    anyway, wish me luck as I really hope not to kill myself or burn the house down. ;-P

  21. I might not understand something, but you simply burned a noodle on a jar and nothing happened

  22. i dont have yeast so i used some calcium carbide and water to make acetylene gas (CaC2+H2O=C2H2) and everything caught on fire

  23. I was actually waiting for the burning noodle in connection with the pure oxigen to set the steel lid of the jar on fire…

    Steel + pure O2 + ignition source = trouble

  24. This dude has the most BLAND jokes I’ve ever heard in my life…it’s like the writers don’t even try…or they’re stoned

  25. "Without [the noodle] covering any of the hole up and without any of the hole escaping of the noodle."
    — Hank Green, 2018

  26. yall got some boring rockets, I build more fun stuff in my kitchen. it aint all about flow its about fuel/oxidizer ratio and compression and jet/nozzle size and for space faring rockets one must observe tsiolkovsky

  27. put this rocket on a kitchen scale that reads out grams. light it and see how much thrust you've created, if there's a measurable amount

  28. You've also made a very weak thermic lance. That's a super hot flame used to cut up big chunks of metal. Carbon rods in a tube, connected to a pure high pressure O2 stream.

  29. worked a bit too well. my building and consequently its residents are currently on the moon…


  30. Thanks for the vid! This will be a good activity to kickstart our study of chemical changes in my Chemistry and Physical Science classes this Fall.

  31. This sort of skipped why rockets move. We cause a pressure to be present inside the rocket. This pressure pushes in all directions against the inside of the rocket and this pressure would push the rocket causing it to move, but in each direction it pushes, it also pushes in the opposite direction, so in gets balanced out & there would be no movement, except that there is one opening –So there is a single direction the pressure is pushing in, (the direction opposite the opening) which is not balanced out.

  32. Toffee, peanut butter and aluminium powder as solid fuel, nitrous oxide as oxidizer.
    Mind you, a glass jar wouldn't be up to the task but it is far safer than storing bottles of hydrogen peroxide.


  33. The coolest application of a hybrid rocket engine must be the Bloodhound SSC, that's the second generation supersonic car.
    Check out the rocket engine at:

  34. what about using solid rocket fuel, like the composite in boosters, as the fuel grain in a hybrid engine? maybe modify it a bit so that it burns much, much slower. Would that increase the power/efficiency?

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