We had such a “blast” shooting off rockets yesterday!  We first decorated our water bottles, then poured 1/2 cup of vinegar in with a funnel.  Then I added baking soda bombs (baking soda wrapped in a single layer of paper towel.)  I sealed up the bottle with a duct tape covered cork and gave it a good shake.  Then the countdown began.  I am happy to report that all 18 rockets successfully launched.  It was worth standing in the roasting heat, maybe! ; ) Be sure to scroll all the way down to see the videos of a few launches.