Hybrid Rockets

When I was in graduate school, I studied rockets quite a bit, specifically the nozzle section. We had an experiment set up we called the “glass rocket” because the burning section was made of acrylic, and it was really only used to amaze people when they come in to tour our lab. Although that I wasn’t able to get a video made of that particular rocket, I found one even better that not only shows the same principle and experiment, but also shows you how to built one yourself… if you really know what you are doing.

I can imagine most folks not being able to build one of these themselves… it is a bit intimidating! The video below shows you how to build a much easier version using yeast, hydrogen peroxide, and pasta. The pasta contains hydrocarbons and serves the same purpose as the acrylic in the previous video (above).

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Materials:

• uncooked pasta tubes with flat ends
• yeast
• hydrogen peroxide
• clean mason jar with lid (NO ring) – cut an 1/8″ hole in the center of the lid
• lighter with adult help

The oxygen flow is generated from the hydrogen peroxide. The hydrogen peroxide molecule looks a lot like the water molecule, only it has an extra oxygen atom. When you add the yeast to the peroxide, it acts as a catalyst and breaks off that extra oxygen, which bubbles up and out of the hole in the lid. It’s important that you don’t screw the lid onto the jar – just rest the lid (without the screw-on ring) on top of the jar.

Since there’s no nozzle on the end of the pasta (although I can imagine how you might wet the pasta and shape it a bit before allowing it to dry), the fluid is going to be pretty slow out the exit tube. We’re also not adjusting the flow at all – it’s flowing at the rate it’s being generated inside the jar.

This particular rocket is a hybrid rocket, which means it uses a solid fuel source (the hydrocarbons in the pasta) and a liquid or gas oxidizer (which is the oxygen from the peroxide reaction). The nice thing about this particular kind of rocket is that you can shut it off if things goes wrong (which you can’t do with solid state rockets, like Estes model rockets or most fireworks). Since the fuel is in a solid state, there’s no big explosion hazard like there is with liquid fuel rockets (imagine having a tank of liquid hydrogen… that’s a big explosion just waiting to happen).

The same type of rocket engine (hybrid) was used in Space Ship One!

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