Photo courtesy of Scientific Explorer

Brief:
This kit is made by Scientific Explorer, Inc. It is a carbon dioxide gas powered rocket. The gas is generated from the chemical reaction of vinegar and baking soda. The fueling module provides a safe and easy separation/mixing chamber controlled by the rocketeer. The kit was purchased from an Edmund Scientific catalog, and is available from other educational/scientific retail outlets.

Construction:
All components were present including extra plastic sheet, silver foil, and balsa for repairs if necessary. These included:

• 1 liter plastic bottle
• plastic sheet for fuselage
• foam tape for nose cone cushioning
• plastic nose cone
• balsa sheet for three fins
• silver self adhesive foil
• high pressure fueling module parts

The instructions are easy to follow with plenty of diagrams. Templates are provided for cutting out the fin pattern and the fin placement on the body tube. Silver foil is applied on both sides of the balsa sheets prior to cutting them out. The instructions say to attach the fins using plastic cement, but I used 30 minute epoxy. One fin came off when the rocket landed heavy with some unreacted vinegar on board, but otherwise this is a good joint. The body is extended by taping a rolled piece of red plastic sheet to the bottom of the bottle. A piece of foam tape is attached inside this rolled plastic sheet to serve as a cushion for the nose cone. The light plastic nose cone is then attached to the fuselage. Except for gluing the fins on the body, all other attachment and assembly is done with silver foil tape. The construction of this rocket is meant to be intentionally fragile so that if it should hit someone, it will disassemble without harming them.

The high pressure fueling module consists of a 1 inch clear plastic tube, a bolt and a sleeve spacer, some washers, a wing nut, and two rubber stoppers. This fueling module stays on the ground upon take-off, and the weight of the module therefore is not included in the listed unfueled weight of 1.9 oz.

Finishing:
There is no finishing involved in this kit, as the color of the components is intended to be enough.

Construction Rating: 4

Flight:
Preparation for flight involves grabbing a bottle of household vinegar and a box of baking soda from the kitchen, and heading to a grassy field with the rocket. First, you put the baking soda into the 1 inch plastic tube of the fueling module. I used 2 teaspoons. The rocket is then held upside down and vinegar poured through the open mouth into the bottle. This is kind of a trial and error process to vary the mix of vinegar and baking soda to get optimum performance. I poured vinegar to the top of the red plastic on the fuselage. The bottle is then tilted sideways so that the vinegar does not spill out, and the fueling module is inserted into the mouth of the bottle so that the baking soda does not spill out of the tube and mix prematurely with the vinegar. Now, you tighten the wing nut on the rubber stopper till you think it is tight enough. The rubber stopper is tightened into the mouth of the bottle so that the gas pressure will build up till it is stronger than the wing-nut pressure on the rubber stopper, and suddenly push the fueling module out and propel the rocket into the air. Therefore, the next step is crucial. Get everybody else to stand away from you the launcher. Turn the rocket upside down again now spilling the baking soda into the vinegar. Shake vigorously for a couple of seconds, then place the rocket on the ground on it's fins and walk away. After the chemical reaction has generated enough gas pressure to blow out the fueling module, the rocket flies straight up to various heights depending on the fuel mix and rubber stopper tightness. In most of my flights, it went about 100 ft high.

Recovery:
Provided you get complete reaction of the vinegar and baking soda, the rocket comes down nose first rather lightly and bounces off the ground. I recommend you stay on grassy fields to soften the blow. One flight, it came down heavy with vinegar still in the bottle and broke off a fin.

Flight Rating: 4

Summary:
This is a fun rocket to teach the kids that all motors are not solid fuel, and to get them thinking about liquid fuel science as well. The body is clear so they can see the fuel both before and after mixing. It is safe provided you follow the instructions. It comes with extra material in case of damage, but you could use other material as well. The only con is the flimsy construction technique of tape rather than glue, but it sure makes it easy for younger kids.

Overall Rating: 4