I would begin my reading the story ‘Zoom to the Moon’ as a stimulus for the activity. I would encourage a class discussion about rockets. I would allow the children to explore with balloons investigating what happens when we blow air into the balloon?, then what happens when we let the balloon go?. I would provide the children with the materials (sellotape, balloons, straws, and string) and I would pose the question to the children ‘how can we make our balloon rocket?’ and allow the children to discuss and experiment with the materials.