Rockets illustrate Newton's third law of motion: "For every action force, there will always be a reaction force that is equal in magnitude but opposite in direction." The first rocket may have been a steam-fueled wood pigeon, invented by Archytas of Tarentum, in the fourth century B. C. The steam then paved the way for the gunpowder tubes of the Chinese, then liquid-fueled rockets designed by Konstanin Tsiolkovsky and implemented by Robert Goddard. This article describes five ways to build your own rocket, from simple to more complex; with an additional section at the end of the article, which explains some of the principles that work when building rockets.
Step
Method 1 of 5: Balloon Rocket
Step 1. Tie one end of the string or fishing line to the support
You can use a chair back or doorknob as a support.
Step 2. Trace the line through the straw
The thread and straw will serve as a guiding system for controlling the balloon rocket's path.
Model rocket devices usually use straws of similar length that are attached to the body of the rocket. These straws are threaded through metal poles on the launch pad to support the rocket before launch
Step 3. Tie the other end to another support
Make sure the thread/string is tight before tying it.
Step 4. Blow up the balloon
Pinch the end of the balloon to keep the air from escaping. You can use your fingers, paper clips, or clothes pins.
Step 5. Stick the balloon to the straw with tape
Step 6. Remove the air from the balloon
Your rocket will fly along the line, from one end to the other.
- You can try making balloon rockets with round balloons instead of long ones, as well as various straws of varying lengths to find out how effective these straws are at guiding the path of the balloon rocket. You can also increase the flight angle of the balloon rocket to see how it affects the rocket's range.
- A related tool you can also make is a jet boat: cut a milk carton in half. Make a hole in the bottom and thread a balloon through the hole. Inflate the balloon, then place the boat into a bathtub filled with a little water, and blow the air out of the balloon.
Method 2 of 5: Rocket Launched by Straw
Step 1. Cut a square of paper
This piece should be about three times the width: the recommended size is 11.43 cm x 3.81 cm.
Step 2. Wrap this piece tightly around a pencil or nail
Wrap it near the ends instead of in the middle. The cut part should hang over the tip of the pencil or nail.
Make sure you use a pencil or nail that is slightly thicker than the straw, but not too thick
Step 3. Glue the paper cut edges to prevent them from coming off
Use tape along the length, along the strip of paper.
Step 4. Fold the hanging ends outwards to form a point or cone
Use tape on this part of the cone to hold the shape.
Step 5. Take out the pencil or nail
Step 6. Check for air leaks
Blow gently from the exposed part of the paper rocket. Listen for the sound of air escaping from the sides or ends of the cone and feel the seams at the sides and ends for airflow. Use tape to seal any leaks and try again until you can't detect any leaks.
Step 7. Add a tail fin on the exposed part of the paper rocket
Since paper rockets are narrow, you may be able to attach the fins you made separately to the ends of the rocket. This will be easier to do than making three or four different fins directly on the exposed part of the rocket.
Step 8. Insert the straw into the open part of the rocket
Make sure the straw is stretched out of the rocket long enough for you to grip it with your fingers.
Step 9. Exhale hard through a straw
The rocket will fly into the air as it is spurred on by the force of your breath.
- Always point the straw and rocket up, not at someone when you launch it.
- Vary the way you build the rocket to see how the modifications affect its flight. Also, vary how hard you breathe through the straw to see how this affects the distance your rocket can fly.
- This paper rocket-like toy consists of a stick with a plastic cone attached to one end, and a plastic parachute attached to the other. The parachute is folded over a stick, which is then inserted into a cardboard blower tube. When blown, the plastic cone will catch the air and launch the wand. When it reaches the maximum height, the stick will drop and activate the parachute.
Method 3 of 5: Rocket Film Roll
Step 1. Decide how long/tall the rocket you want to build
A good length/height of the rocket is 15 cm, but you can make it longer or shorter if you wish.
A good diameter is 3.75 cm, but the actual diameter will be determined by the diameter of the rocket's combustion chamber
Step 2. Prepare the roll/roll of film
This roller will be the combustion chamber for your rocket. You can get rolls of film from photo studios that still use film.
- Look for a roll of film with a cover that looks like a stopper that goes into the mouth of the roller, instead of being stuck on the outside.
- If you can't find a roll of film, you can use an empty prescription medicine bottle, with a snap-on lid. If you can't find it, you can use a cork stopper which will fit nicely into the mouth of the bottle.
Step 3. Assemble the rocket
The easiest way to make a rocket body is to wrap a strip of paper around a roll of film, the same way you would wrap a pencil or nail when making a rocket launched by a straw. Since the rollers will launch the rockets, you may want to attach the paper to the rollers using tape or glue - before wrapping them around the container.
- Make sure that the mouth of the roller or pill bottle is facing outward when you attach the rocket housing. The mouth will serve as the rocket nozzle.
- Instead of folding the ends of the rocket body away from the rollers into the cones, you can create separate cones by cutting a circle of paper, from the edge to the center, and folding the paper into a cone. You can attach the cones with tape or glue.
- Add fins. Since the diameter of this rocket is thicker than the paper rocket you launch with a straw, cut each fin one at a time to attach them. Also make sure you use three fins instead of four.
Step 4. Determine the launch location of the rocket
The open outdoor location is the one we recommend, as the rocket can reach a fairly good height when launched at this location.
Step 5. Fill the roller with water up to 1/3 full
If the water source is not near your launch pad, you may have to carry the rocket upside down or carry the water separately and fill the rollers on the launch pad.
Step 6. Cut the effervescent tablet in half and put the other half in the water
Step 7. Close the rollers and turn the rocket so that it is perpendicular to the launch pad
Step 8. Move away at a safe distance
As the tablet begins to dissolve, it releases carbon dioxide. The pressure will accumulate until it breaks and releases the roller cover allowing the rocket to launch.
In addition to water, you can fill the roller with vinegar halfway up. Instead of effervescent tablets, you can use 1 teaspoon (5 g) of baking soda. Vinegar, which is an acid (acetic acid), will react with baking soda (which is the base ingredient), to produce water and carbon dioxide. However, vinegar and baking soda are more volatile than water and effervescent tablets, so you'll need to get away from the rocket faster – and using too much of both chemicals can destroy the rollers
Method 4 of 5: Rocket Matches
Step 1. Cut small triangles out of aluminum foil
This triangle should be isosceles, with a length of approximately 2.5 cm at the base and 5 cm from the center of the base to the apex of the triangle.
Step 2. Take matches from the group
Step 3. Align the matches with the straight pins
Place the match and pin so that the point of the head of the pin touches the head of the match, at a position no higher than the thickest part of the head.
Step 4. Wrap the foil triangle, starting at the top point, around the head of the match
Wrap it as tightly as possible without disturbing the pin position. When finished, the wrap should extend about 6.25 mm below the match head.
Step 5. Fold the foil wrap around the pin head with your thumb nails
This will press the wrapper closer to the match head and create better pin channel under the wrapper.
Step 6. Carefully remove the pin from its wrapping
Take care not to tear the foil as you do this.
Step 7. Bend the paper clip into a launch pad
- Bend the outside at a 60 degree angle. This will form the base of the launch pad.
- Bend the inner groove upwards, then twist it so that it forms an open triangle. This will be where you put your foil-wrapped matches.
Step 8. Place your launch pad on the launch location
Again, an open outdoor location is highly recommended, as match rockets can travel considerable distances. Avoid locations that are very dry, as match rockets can cause fires.
Make sure the area around you is safe before launching the rocket
Step 9. Place the match rocket on the launch pad, with its head facing up
The rocket must be positioned at least at a 60 degree angle. If it's lower, you may have to bend the paper clip until it reaches this position.
Step 10. Launch the rocket
Light a match just below his wrapped head. When the phosphorus in the wrapped match head ignites, the match rocket will fly.
- Prepare a bucket of water that is useful for soaking used matches, to make sure these matches are completely extinguished.
- If the match rocket lands on you, stop moving, drop to the ground, and roll until all the flames are out.
Method 5 of 5: Water Rocket
Step 1. Prepare an empty 2 liter soda bottle
This bottle will serve as a pressure chamber on the rocket. Because bottles are used to make these rockets, they are sometimes called bottle rockets. Don't mistake it for fireworks, also called bottle rockets, which are so named because they are often fired from inside a bottle. Bottle rockets like this are illegal to launch in many areas; while water rockets are legal in most areas.
- Remove the bottle label by cutting it where it is not glued to the bottle. Be careful not to cut or puncture the surface of the bottle while doing this, as scratches or cuts will weaken the bottle.
- Reinforce the bottle by wrapping it with a duct tape. The new bottles can withstand pressures of up to 100 pounds per square inch (689.48 kilopascals), but repeated launches will reduce the pressure tolerance the bottles can handle without cracking. You can wrap several layers of masking tape around the center of the bottle, or wrap the center and continue halfway down the bottle toward each end. Each pack must go around the bottle twice.
- Mark the places where you will attach the fins to the body of the rocket, with a marker pen. If you plan to use four fins, draw the lines at 90-degree angles apart. If you plan to make three fins, draw the stripes 120 degrees apart. You may want to circle a piece of paper around the bottle and mark it first before transferring these markings to the bottle.
Step 2. Make the fins
Since the plastic rocket body is quite strong, even if you have to strengthen it again, your fins should also be durable. You can use hard cardboard, but a better material is plastic used in a pocket folder or binder with three rings.
- First you need to design your fins and make a paper sample as a cutting guide. However you design your fins, you have to make them so that the real fins are folded again (doubled) to get extra strength and reach the point of bottle constriction.
- Cut the sample and use it as a guide for cutting the fin material.
- Fold the fins into shape and attach them to the body of the rocket with tape.
- Depending on the design of your launcher, you may not have to build a fin that goes through the nozzle of the rocket.
Step 3. Make the nose cone and the cargo part
You will need a second 2 liter bottle for this.
- Cut the bottom of the bottle.
- Place the load on the top of the cut bottle. This piece can be model clay or a bunch of rubber bands. Place the cut bottom of the bottle inside the top, with the bottom pointing toward the top of the bottle. Stick it with tape, then attach the modified bottle to the bottom of the bottle which acts as a pressure chamber.
- Your nose cone can be made of anything from a 2 liter bottle cap to a PVC pipe of any length, to a real plastic cone. Once you've defined and created it, this cone should be permanently attached to the top of the cut bottle.
Step 4. Test the balance of your homemade rocket
Balance the rocket on the index finger. The rocket should be balanced at a point above the pressure chamber (bottom of the first bottle). If not, remove the load portion and adjust the weight.
Once you've found its center of mass, weigh the rocket. The weight should be in the range of 200 to 240 grams
Step 5. Create the launcher/stopper
There are several pieces of equipment that you can use to launch your water rocket. The simplest is a valve and a stop that can be inserted into the mouth of the bottle which functions as a pressure chamber.
- Look for a cork that fits right into the mouth of the bottle. You may have to scrape the edges a bit.
- Get a valve system commonly used in automobile tires or bicycle inner tubes. Measure the diameter.
- Drill a hole in the center of the valve, with the same diameter as the valve.
- Clean the valve stem and apply tape over the threaded portion and opening.
- Insert the valve through the hole in the cork, then hold it in place with a silicone or urethane seal. Allow this substance to dry thoroughly before removing the tape.
- Test the valve to make sure air can pass through it freely.
- Test the stop by placing a small amount of water in the pressure chamber of the rocket, then placing the stopper in position, and erecting the rocket vertically. If there is a leak, re-seal the valve and test again. Once there are no leaks, test again to find the pressure forcing the air to expel the stopper from the bottle.
- For instructions on creating a more advanced launch system, see
Step 6. Select your rocket launch site
As with film roll rockets and lighters, an open outdoor location is highly recommended. Since water rockets are larger than other rockets, you'll need a larger, flatter open area than other rockets.
Raised surfaces, such as picnic tables, are a good idea when small children are present
Step 7. Launch your rocket
- Fill the pressure chamber 1/3-1/2 full with water (you may be able to add food coloring to the water to give it a more colorful "fuel" when the rocket launches). You can also launch a rocket without using any water in the pressure chamber, although the target pressure may be different than when the chamber had water in it.
- Insert the launcher/stop into the mouth of the pressure chamber.
- Connect the bicycle pump hose to the release valve.
- Stand the rocket upright.
- Pump air until you reach a pressure that will force the valve out. There may be a bit of waiting time before this happens and the rocket launches.
Rocket Parts and How They Work
1. Using fuel to lift the rocket and fly it through the air. Rockets fly by directing fuel vapor down through one or more exhausts which will push it up (lift it) and move it forward (through) the air. Rocket engines work by mixing real fuel with an oxygen source (oxidizer), which enables the rocket to work in outer space other than Earth's atmosphere.
- The first rockets were solid-fuel rockets. These rockets include fireworks, Chinese war rockets, and the two thin boosters used by spacecraft. Most rockets like this have a hole in the middle, which is used as a place for the fuel and oxidizer to meet and burn. The rocket motors used in model rockets use solid fuel, as well as a group of currents to launch the rocket's parachute when the fuel runs out.
- Liquid-fueled rockets include separate pressurized tanks containing a liquid fuel such as gasoline or hydrazine and liquid oxygen. These fluids are pumped into the combustion chamber at the bottom of the rocket; Exhaust gases are expelled through a conical snout. The main thrusters of the spacecraft are liquid-fuel rockets supported by external fuel tanks, which are carried under the craft at launch. The Saturn V rockets on the Apollo missions were also liquid-fueled rockets.
- Many rocket-powered aircraft also use small rockets on the sides to help steer the plane while it is in the sky. These rockets are called maneuver thrusters. The service module on the Apollo command module has these thrusters, the Manned Maneuvering Unit backpacks used by spacecraft astronauts also use these thrusters.
2. Cut air rejection with its conical nose. Air has mass, and the denser it is (especially the closer it is to the earth's surface), the more it will fight against objects trying to pass through it. Rockets must be designed to be streamlined (with long elliptical shapes) to minimize impact as they pass through the air, and, for this reason, rockets have a conical nose tip.
- Rockets that carry payloads (astronauts, satellites, or nuclear explosives) usually carry these payloads in or close to the nose of the rocket. The Apollo command module, for example, is conical in shape.
- This conical nose also carries all of the rocket's control systems to help direct it to its destination without being hampered. Control systems may include in-cab computers, sensors, radar, and radios to provide information and control the rocket's flight path (Goddard rockets use a gyroscope control system).
3. Balancing the circle around its center of mass. The overall weight of the rocket must be balanced around a certain point on the rocket, to ensure the rocket can fly unhindered. This point can be called the equilibrium point, the center of mass, or the center of gravity.
- The center of mass for each rocket varies. In general, the balance point will be above the fuel or pressure chamber.
- While the payload helps raise the rocket's center of mass beyond the pressure chamber, excess payload will make the rocket heavy on top, making it difficult to hold up during launch and control during flight. For this reason, integrated circuits were combined with spacecraft computers to reduce weight (this led to the use of similar integrated circuits, or chips, in calculators, digital clocks, personal computers, and, more recently, these, tablet computers and smartphones).
4. Balancing the flight of the rocket with its tail fins. These fins help ensure that the rocket's flight is straight, by providing air resistance to changes in direction. Some of the fins are designed to pass through the bottom of the rocket's nozzle, as well as to keep the rocket upright before launch.
In the 19th century, the Englishman William Hale discovered another way to use rocket fins to stabilize rocket flight. He made a drain right next to the fins that resembled a propeller. This causes the wasted gases to compress the fins and rotate the rocket to keep it out of line. This process is called rotating stabilization
Tips
- If you enjoy making the above rockets but want to take on a tougher challenge, you can work on a hobby model of a rocket. Model rockets have been on sale commercially since the late 1950s, in the form of interlocking equipment that could be launched with black gunpowder engines, to heights of 100-500 m.
- If it's too difficult to launch the rocket vertically, you can make some of it glide horizontally (in fact, balloon rockets are a form of this horizontal glide). You can attach a film roll rocket to a toy car or a water rocket to a skateboard. You should still find an open area with a large enough launch space.
Warning
- Parental supervision is strongly advised when working with any rocket launched using anything stronger than the breath of the person launching it.
- Always wear eye protection when launching any of the three types of flying rockets (rockets other than balloon rockets). For larger free-flying rockets, such as water rockets, a protective helmet is also recommended to protect the head if the rocket hits it.
- Do not fire free-flying rockets of any type at anyone.
