Materials you need;
1. a 2 litre bottle.
2.a rubber cork from chemistry lab.
3. a pin used to fill air in footballs etc.
4. air filling hand pump.
5. a hammer.
6. a nail .
8. two persons one with good strength.
take a 2 litre plastic coldrink bottle (coke,fanta, etc. ). take a cork which is used in chemistry as lids of flasks. make sure it should be of rubber and should fit to bottle's mouth. take the nail and pierce it through cork with hammer. make sure that the whole you are making should not be broad than air filling pin. put the pin inside the cork through the hole. fill the bottle to 1/3, put the cork tightly in mouth of bottle. connect the pin with pump's wire. one would hold the rocket bottle from its mouth along with cork. the person with good strength will pump air into bottle as fast as he can. hold the bottle strongly , so that enough pressure in bottle can be made. after you feel that enough pressure is there leave the bottle but keep holding the cork, and boom rocket will fly. you can also make it decorative. as it was only proto model. you can also make its base. take a rectangular cardboard piece of length about 20 to 25 cms. make it a cylinder. now make its fins. attach them to cylinder. there is no need to attach the base to rocket just make it in the way that rocket should stand on it. now when you will make this base it will also look good and there will not much weight on rocket.