You will need
- Clean, empty plastic bottles (500ml)
- Paper drinking straws
- Sticky tape
- Big pieces of card
- Pens or pencils
- Clean items of recycling
- White vinegar
- Bicarbonate of soda
- Paper towels
Before you begin
- Find an outdoor spot suitable for launching bottle rockets. This activity may be best suited to a countryside or camp setting.
- Before the session, encourage everyone to bring along with them any used 500ml plastic bottles. These should be rinsed out.
- They should also bring materials that they would use to design and build a bottle rocket. This might include sweet wrappers, cereal boxes or used packaging.
Build your rocket
- Everyone should get into small groups. Give each group a bottle, tape and three straws.
- The straws should be taped to the top of the bottle, so they act like a stand for the upside-down bottle. Wrap tape around the bottle to secure them in place, without bending the straws.
- Everyone should get some cardboard and use a pencil to draw four rocket fins and cut them out with scissors. Stick these to the sides of the bottle with tape.
- Groups should then use the remaining cardboard to make a cone to go on the tip of their rocket (the bottom of the bottle). Secure this to the bottle with more tape.
- Give each group a cork to fit the neck of their bottle. The cork needs to fit securely, so pressure can build up inside the bottle, but not so tight that it won’t be forced out to launch the rocket. They can use some tape to wrap around the cork to make it fit more securely if they need.
- Head outside to the launch site. Each group needs to take bicarbonate of soda, paper towels and vinegar with them.
- Each group should measure a teaspoon of bicarbonate of soda into a paper towel. Roll up the towel into a sausage shape, making sure the powder doesn’t spill out. The sausage needs to be skinny enough to fit into the bottle through the neck.
- Each group needs to fill their bottle halfway with white vinegar. Then, quickly, stuff the parcel of bicarbonate of soda into the bottle, replace the cork securely and turn the bottle upside-down. Stand it on the straws and step back at least two metres. The cork should shoot out and the bottle should fly into the air.
- Everyone should come together to discuss their bottle rockets. See if anyone knows why they shot up into the air.
- Have each group retrieve their rocket and change one feature about the design. This might be the shape of the nose cone, the shape or position of the fins or the size of bottle they use. Then, they should launch the new rocket. See if anyone’s rocket flew further or was more stable in the air this time around.
- Once everyone has completed the experiment, dismantle the rockets, wash out the bottles and recycle the materials used.
Working as a team was important to design and build rockets that flew well. Space rockets need a huge team of experts to get them to work. How did your group work together, with everyone using their individual skills, to make the launch a success?
Someone had to be brave to stuff the paper towel in the bottle, cork it and step back. The paper towel acts as a time release, allowing enough time to step away from the bottle before it takes off. Still, pretty brave! Did everyone take turns to do this bit, or did one person take responsibility?
Supervise young people, and only do science activities that are advised and age appropriate for your section. Test activities first, to make sure you’re confident you can lead them safely. Use protective clothing where necessary.
Supervise young people appropriately when they’re using scissors. Store all sharp objects securely, out of the reach of young people.
- Rubbish and recycling
All items should be clean and suitable for this activity.
Before completing this activity make sure you have suitable personal protective equipment (PPE). This could include eye or ear protection, gloves, and anything else you need to protect yourself. You’ll know what you need as a result of completing the risk assessment for the activity.