Works with either a specialized water rocket or soda bottles. Launches are unpredictable, which adds excitement. Can be modified with an air compressor for maximum height.
Requires a smaller Presta air pump or adapter, not a standard bike pump. Fins are not durable. Some consumers report not receiving the pump.
Bottle rockets with optional fins can reach incredible heights. Accurate air pressure valve provides scientific data. Designed for common two-liter bottles.
Does not work well with all sizes and brands of soda bottles. Launch mechanism can jam, requiring manual release. Safety valve can leak under low PSI conditions.
Significant launch heights achieved. Can be modified for multiple launches with air compressor. Accepts virtually all sizes of plastic bottles for launch.
Instructions are difficult to interpret. Fins are more decorative than functional. Launching mechanism requires frequent adjustment.
Kit includes everything needed to assemble the rocket. Affordable. Cool retro style. Reusable rocket. Launches up to 100 feet. Easy to assemble. Sturdy. STEM toy.
Younger kids will need adult help for assembly.
Comprehensive kit includes everything needed to build rocket. Reusable rocket. Easy to assemble. Bright colors make it easy to find after launch. Sturdy. Launches up to 100 feet.
Finding the best water pressure for a successful launch is a trial and error process.
We recommend these products based on an intensive research process that's designed to cut through the noise and find the top products in this space. Guided by experts, we spend hours looking into the factors that matter, to bring you these selections.
Bottle launchers have been around for a very long time, but they got their biggest boost in popularity in the mid-1970s with the introduction of the 2-liter soda bottle. This allowed the construction of bottle launchers that could fire a clear plastic “rocket” 100 feet or more into the sky.
Bottle launchers aren’t just fun, they’re educational, too, encompassing all aspects of the widely taught STEM concept (science, technology, engineering, and math). In fact, they’re so highly regarded that the University of Nebraska says they may be the “greatest physical science teaching tool ever created!”
Not surprisingly, when you’re buying a bottle launcher you have lots of choices, everything from lightweight kids’ toys to devices that can put two or three soda bottles in the air at the same time. To help you decide which is best, we’ve been looking at what’s currently available and made a number of recommendations that highlight price and performance options. In the following buying guide, we look in more detail at what you get for your money.
It’s easy to picture pumping a bottle full of air and then hitting a button to make it shoot into the sky. Compressed air launchers do exist, so why do we add water to these bottle launchers? There are two reasons: stability and propulsion.
Stability: The first reason is stability at takeoff. Two-liter soda bottles are very light. Even with the addition of fins and a nose cone, the slightest breeze can either topple them over or blow them off course as soon as they’re launched.
Propulsion: The second, and more important, reason is to act as a propellant, the “rocket fuel,” if you like (this is where some of the science comes in). Water is a lot heavier than air, so when it’s pressurized and suddenly expelled through a narrow aperture at the tail of the rocket, it generates much more thrust than air could alone. As a result, your bottle rocket goes higher — claims of 90 feet and more are common. Some have been known to exceed 250 feet, though there’s limited choice when it comes to rockets of this power available commercially.
Let’s first look at the things you don’t get and will need to provide yourself: most bottle launchers don’t provide the soda bottle or pump. The first is simple. Just finish that soda in the fridge and give it a quick rinse. The second is usually something you probably already own: a bicycle tire pump. Alternatives include a small electric tire compressor or tool compressor.
For what does come in the kit, cheap DIY bottle launchers provide you with a set of fins to stick on your bottle, an air valve that screws on the top, and a hose to attach to your pump. There’s no kind of launchpad; the fins rest directly on the ground (so you need to find somewhere level). There’s also no launch control. The bottle rocket takes off when you’ve pumped enough air in to reach a preset pressure.
Pay a little more and you’ll get a bottle launcher that incorporates a few more features. These look better, they’re more durable, and they offer more control in general. These additional components include the following:
Pay more for a high-end model and it will be more durable and potentially offer greater control over performance. The maximum height we’ve seen claimed for one of these systems is 350 feet. What’s more, the robust construction makes performance very repeatable. This is important for science projects in which you want to be able to monitor the effect of small changes in water volume and air pressure. These more expensive kits have the following features:
There are also models that launch more than one bottle, with valves that allow for pressurization at the same time and trigger mechanisms that offer a choice of separate or combined launch. These require some assembly, but all the parts are included. They’re usually made of PVC pipe which is strong enough to handle the pressures involved and tough enough to take the kind of beating dealt by enthusiastic kids.
Most bottle launchers are designed to launch the rocket vertically, but that’s not always the case. Rail systems exist that launch at a fixed angle, and some can be adjusted. From a teaching point of view, this incorporates ballistics, projectile engineering, Newton’s laws of motion, and more. However, great care is needed with this type of bottle launcher. You need a clear flight path and plenty of margin for error in your safety calculations. It’s generally recommended that an adult be present when launching bottle rockets, and it’s even more important with this type.
Inexpensive: The cheapest bottle launchers that cost less than $25 are DIY kits. They are quick and simple to build, but they don’t have any kind of launchpad and offer limited control over pressure. They’re fine for a bit of low-cost fun, but offer little in the way of educational merit.
Mid-range: The majority of bottle launchers cost between $25 and $50, and most low-power models designed for smaller children are within this bracket. Also included are those that can launch multiple bottles simultaneously (minimal assembly is required).
Expensive: There are a few bottle launchers made with high-quality chromed steel and brass components. These offer tremendous durability, and they cost between $60 and $100.
Q. Is there any risk of a bottle exploding?
A. It’s unlikely. Most modern soda bottles are designed to withstand at least 90 psi (though it’s likely they can exceed that). We’ve seen some bottle launchers that run to 120 psi, but they’re less common. Most max out at less than 60 psi.
It’s also worth noting that when deliberately tested to destruction, almost all bottle failures result in a loud bang, but no flying debris. If you establish a safe perimeter before launch, there should be no danger.
Q. Could a falling bottle cause damage or injury?
A. It’s possible but unlikely if you follow the recommended safety precautions. Your neighbor might not be happy with a bottle falling on their car or prize rose bushes, but an empty soda bottle weighs a couple ounces, so the impact should be negligible. Unexpelled water will add weight (though the farther it flies, the less water will be left), which is why it’s important to establish a safe area around the launch site, follow the instructions carefully, and only test variations when you’ve gained some experience with your launcher’s standard performance.
Q. Can I make a bottle launcher myself?
A. Of course! There are lots of instructions online — from basic to complex — and plenty of informative videos. It can be a lot of fun. Putting it all together takes time, and you need to be patient if you want to build one you can use again and again. The advantages of buying a premade bottle launcher or bottle launcher kit are that you know all the parts have been designed and tested for you, and it can very quickly be ready for flight.