HORIZONTAL BOTTLE ROCKET - Utah 2008

 DESCRIPTION: Teams will design, construct, and launch two rockets to hit nearest a target.

A TEAM OF UP TO: 4 (2 members will perform the launches)

APPROXIMATE TIME: 8 mins. for each prep and launch

1) CONSTRUCTION:

a. Students will bring two rockets for the tournament. One made from a one-liter and one made from a two-liter carbonated beverage bottle with approximately 2.2 cm (internal diameter) nozzles. For the safety of all involved in the event, any bottle that does not withstand the pressure applied to launch (I.E. Explodes!) will be ranked at the end of the teams and will receive participation points only. No modifications may be made to the flange (just below the threaded portion of the nozzle) of the bottle. Bottles may not use extenders that exceed the 1L or 2L volume for water and pressure. No commercial model rocket or parts may be used. Before impound, the rockets must be marked in such a way that the event supervisor can easily identify to which team they belong.

b. The structural integrity of the pressure vessel cannot be altered. Examples of altering structural integrity includes but are not limited to physical, thermal, or chemical damage (e.g. cutting, sanding, using hot glues, or super glues). Adhesive may be used to attach fins and other components but must be limited to glue such as silicone adhesive, polyurethane based adhesives and others that do no damage the structural integrity of the pressure vessel.

c. All components used for ballast and balance must allow for clear visual inspection of the pressure vessel. (I.E. if the nose cone is covered with duct tape there must be another area that allows the supervisor to visually inspect the pressure vessel to verify that no damage, from sharp objects or weakened pressure vessel, will occur during launch)

d. Metal may be used, but may only be attached to the cone or fins. Metal cannot contact the pressure vessel at any time. For safety reasons, rockets may not use sharp or pointed metal components or a leading surface consisting of a rigid spike. The total mass of the rocket cannot exceed 250 grams for the one-liter and 350 grams for the two-liter rockets.

e. Materials used in construction of rockets should be considered carefully. Due to the nature of the event, and to the unpredictable nature of the elements, it is almost certain that the rocket will come in contact with water.

f. The maximum extended length of the rockets and their components shall not exceed one (1) meter.

g. All propulsive energy imparted to the rocket must originate from the water/air pressure combination provided by the judges. Other forms of potential and kinetic energy may be used for deployment of the rocket components, if used. No pyrotechnics or pressurized gases (except for the original air pressure) may be used at all. No remote controls are allowed.

2) THE COMPETITION:

a. All rockets must be impounded one hour before the start of the competition and will be released back to the teams immediately after completion of their launches. Once impounded, no physical alterations may be made to the rocket. Appeals will be addressed based on event coordinators data logs and pictorial impound data. All rockets must be picked up from the event location at the time the individual team’s launches are completed. Any rockets not picked up will be disposed of.

b. Teams will receive instructions on the use of the launchers, upon arrival at the scheduled launch time, and prior to the rockets being picked up from impound. Only team members are allowed to pick up their rockets and proceed to the designated staging area. The first eight minute period (for the first launch) will include additional adjustments (No modifications or alterations, adjustments only) to the rockets, adding water, adjusting the angle of the launcher, and the launch. Rockets will only be staged one at a time. The second rocket must remain in impound until the first rocket is launched and measured. The second launch will receive a new eight minute period. Any rocket launched before the time expires will be scored. Teams must provide and wear safety glasses once they enter the staging area to begin setup and launching. Teams that do not have safety glasses will not be allowed to launch.

b. All rockets will be launched using the launcher provided by the supervisor. It is the team member’s responsibility to ensure that their rockets are capable of launching from the launcher provided. Teams may not bring a device to shield their rockets from the wind while on the launcher. The team members must provide a protractor for measuring the launch angle, as well as any device needed to measure water (including funnels, if needed to fill rocket).

c. All rockets will be launched at a pressure greater than 10 pounds per square inch (psi), and not to exceed 60 pounds per square inch (psi). Once the rocket is pressurized, NO team member is allowed to touch or approach the rocket, until the pressure is removed using the safety release valve, or a launch. To the best extent possible, launches will be made with the direction of the wind.

d. Rockets will be launched at a fixed target between 25 and 65 meters away from the launch sight. The target will be horizontal on the ground, NOT standing vertical. The target will be a circle one meter in diameter. Any part of the rocket nose landing in the target area will be considered a direct hit. Distance will be measured from where any part of the rocket first touches the ground.

e. Teams must bring a data table showing the angle for the launcher and air pressure for various target distances. Teams must also bring a rocket building journal. The journal should show the stages of building the rocket as well as calculations used to set the rocket up for optimum flight. Teams that do not bring the data table or journal will still be allowed to launch but will be ranked below those that have this data.

f. Measurements will be made from the point where any part of the rocket first touches the ground. The judges will mark the point where the rocket first hit the ground.

g. Only one launch is allowed per rocket and each rocket must be launched (one 1L and one 2L rocket)

h. The competition distance will be given when teams arrive for impound the morning of the competition. At this same time teams will receive the Angle and Pressure used by the supervisors to hit the target. These parameters will be based off of a rocket designed by the supervisor and meeting all event requirements such as weight, length and materials.

SCORING:

a. All distances will be measured to the nearest centimeter. Preferably, at least two judges will verify the measurements. The winning team will be determined by the lowest combined distance from the target for the two rockets. Distance is measured from the outer edge of the one meter target.

b. Rockets that violate construction rules will be ranked next.

c. Teams not allowed to launch their rockets because participants did not have safety glasses, their rockets failed the safety inspection, or their rockets could not withstand the selected launch pressure will receive participation points only.

d. Tie breakers: The team that had the closest distance for either launch will be the winner. In cases where two teams tie with the closest distance of a single rocket, the winner will be the team with the shortest total rocket length for the two-liter rocket. If there is a tie in the rocket length, the winner will be the 2-liter rocket with the least mass (without water added).