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Blast Off!
Eighty years ago, American scientist Robert Goddard launched the first rocket that used liquid, not solid, fuel. The flight only lasted a few seconds, but Goddard predicted that one day, rockets would make it into space. Some people laughed at his idea, but Goddard was right! Liquid fuel gives rockets the thrust they need to blast off.
Make your own mini-rocket in this activity. Its wet, so do it outside!
What You Need
Aluminum foil (optional)
Stickers, glitter, or other craft supplies (optional)
Alka-Seltzer tablet
Fuji brand film canister and lid (photo labs often give these away)
Water
Safety goggles (swim or ski goggles work, too)
What to Do
1. If you want, decorate your film canister with the foil, stickers, and other craft materials. This is your rocket.
2. Break the Alka-Seltzer tablet in half.
3. Half-fill the film canister with water.
4. Put on your safety goggles.
5. Place the Alka-Seltzer tablet in the film canister. Quickly put on the lid and place it on the ground lid side down.
6. Stand back and countdown to lift off!
7. Try your rocket again, using different amounts of water. Or, use warm water. Does this change how quickly the reaction happens?
How it Works
Although your rocket contained a liquid (water) and a solid (the Alka-Seltzer tablet), it was a gas that provided the fuel for blast off. As the Alka-Seltzer dissolved in the water, the gas carbon dioxide formed. The gas filled the container and created enough pressure to blow the canister free from its lid.
In real rockets, liquid fuels are burned. As they burn, hot gases push down and out through a narrow nozzle. This moves the rocket in the opposite direction and up, up, up and away into space.
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