Everyone loves explosions. Whether you’re the sort of person who enjoys setting off explosions, or you’re simply in awe of the kind of power that can be released from a chemical reaction, explosions are captivating for everyone, whether we admit it or not. What better way to give your model rocket some flare than by cooking your own sugar rocket fuel? Not only do you save money this way, it’s also significantly more fun and DIY, giving you a greater sense of achievement when you finally get the reaction going.
Rocket chemistry is no easy feat and requires some research and basic chemistry knowledge before I recommend dabbling in it. Keep reading to find out what I learned cooking my own sugar rocket fuel for my rocket Horizon I. Whether you’re just interested in how I was able to achieve this, or you’re looking to cook your own rocket fuel, this article is for you.
What exactly is rocket fuel?
There are many kinds of rocket fuel, some used in industry and some not. For my rocket, I developed the simplest kind of fuel – sugar rocket fuel. This fuel gets its name from the amount of sugar used in it to allow the reaction to occur, as well as the smell produced when this fuel is burned. However, all kinds of solid rocket fuel require:
- Some sort of fuel element (in this case, sugar). You can think of this part of the fuel like the “wood” that feeds the fire.
- An oxidizer. This can be one of many chemicals. You can think of this like the air around the fire that keeps it going. In the case of solid rocket fuel, we want a very strong and intense burn, which requires extra oxygen. That’s what oxidizer is for.
What ingredients did I use for my sugar rocket?
I selected an artificial sugar named sorbitol for my rocket. Sorbitol doesn’t burn like table sugar would, so its a good choice to melt together with my oxidizer and get the consistency I want. In this case, I’m going for a consistency like cake batter when heated. Buy sorbitol on Amazon here.
For my oxidizer, I chose potassium nitrate (KNO3). This is fairly easy to get your hands on, which is why I chose it. I was able to order this online on Amazon, but if you can’t manage to order it, you can also find it in products such as tree stump remover. You would need to decant the stump remover to extract the potassium nitrate.
What ratio did I use for each ingredient in my rocket fuel?
In my experience, a good mixture for cooking sugar rocket fuel is 65/35 oxidizer to fuel. This means if you want to make 100 grams of fuel, you would use 65 grams of potassium nitrate and 35 grams of sorbitol. These ingredients need to be mixed together and heated, which I will cover in the next section.
How did I cook the sugar rocket fuel?
In order to cook the fuel and mix it up as thoroughly as possible, I took a coffee grinder and ground up both the sorbitol and the potassium nitrate into smaller particles. This helped the two of them mix up more evenly into the fuel, and gave me a more consistent, steady burn.
I poured the two ingredients onto a hot plate once grinded down, and mixed until I noticed them beginning to melt. At this point, I turned down the temperature a little on the hot plate to allow the particles to blend and melt together. But I learned through trial and error that too much heat and the fuel will turn brown, burning the sorbitol in the mixture. In order to avoid this,I slowly feathered the heat once I noticed melting began. I continued to stir until the whole mixture was melted and had a consistency similar to cake batter.
And now for the fireworks!
Once I successfully cooked my fuel, I waited for it to cool down and harden into a solid. But before it fully cooled, in order to shape it in the form I wanted it in, I kept it at its melting temperature without burning it This can be a difficult task with a cheap hot plate, but if you can fine-tune temperature this will be easier.
Once the fuel was fully cooled and solid, it’s ready to use. I tested this several times to ensure I had the right ratios and consistency. In the below video you can see that I tested it on the ground in a safe place where nothing could set on fire (do not do this in a drought or anywhere that could set fire such as a forest – be smart!) I needed a fairly hot flame to get this fuel going, so I had to use a blowtorch instead of a lighter or match.
And that’s how you cook rocket fuel! Please use this knowledge responsibly, and have fun with your model rocket endeavors! Remember, failure is just a step along the way to success.
