Those little valves have a backstory
Partway through the build, Adam found two rubber valves shaped like a duck's bill and got genuinely excited about them.
Our first prototype dropped in water, baking soda, and citric acid all at once. The fizz started early and most of the carbon dioxide escaped before the rocket ever reached the launchpad. Rebecca, one of our product designers, wanted to capture all of that pressure and hold onto it. She found a way to do exactly that by first sealing the rocket, then using a syringe and two duck bill one-way valves to draw water from a reservoir bottle and drive it into the rocket. One bottle of water covers several launches, and since the powders stay dry until the water arrives, nothing happens until you're ready to start the countdown.
Pushing the syringe by hand turned out to be a workout, so she built it into a dynamite-style detonator.
The fizz does the work
The chemical reaction works a lot like a shaken soda can. Citric acid and baking soda meet water and give off carbon dioxide in a hurry, which is why you push the water in fast; the pressure builds as you go and starts pushing back. The Science Behind Bottle Rockets is a great place to learn more about the physics of the flight.
Why Adam loves this stuff
He's launched plenty of rockets on MythBusters, and he credits the toys he played with as a kid for part of that.
The Bottle Rocket Blaster is a Tinker Crate project for ages 9 to 12, and everything you need is in the box.
In Adam's video, he wondered whether the amount of powder changes the flight and left the answer to you. Give it a try and report back. Share your launch photos and videos on Instagram and tag @kiwico_inc.
