The vector design must conform to the requirements outlined in this document.

2.1    Physical

The vector’s total dimensions shall not exceed the following:

• Maximum length = 5 m;
• Maximum wingspan = 25 m;

The launch angle will be 85 degrees, an offset of 5 degrees from vertical, with a tolerance of +/- 3 degrees. Measurement devices will be used to check compliance with this rule, and a penalty will be applied if compliance is failed.

The primary structure of the vector shall be formed of readily available items forming two or more water tanks:

• 1 unpressurised tank containing a minimum of 500ml of water. The tank must contain 50% water and 50% air to generate sloshing loads. The fill level at 50% volume must be clearly marked to facilitate easy visualisation for the judges. The minimum cross sectional area should not be less than 50% of the maximum cross sectional
• 1 or more pressurised tanks containing water for Only these pressurised tanks will be allowed for propulsion. Any pressurized tanks used for the purpose of propulsion must launch with the rocket, and can only be discarded once airborne. The tanks will be checked to ensure they can be pressurized to the desired amount before launch.

The total mass of the propellant must be no greater than the mass of the sloshing liquid.

The total weight at take-off shall not exceed 5 kg when filled with liquid.

Teams will be given the opportunity to launch their rockets up to three (3) times during the finals. As a result, a rocket design that is recoverable and relaunchable is heavily recommended.

The judges would like to stress the importance of approaching the challenge with a flexible and fresh mind, meaning that arrangement of the tanks does not have to conform to a traditional rocket shape. Teams are not only warmly encouraged to consider aircraft concepts benefits and drawbacks, but are also expected to include an in-depth investigative analysis in the introduction to the technical report about ideas and researches in other disciplines that aviation should take inspiration from.

2.2    Launch Mechanism

The vector must be launched vertically at a pressure less than 10 atmospheres [or 147 psi]. The rocket design shall incorporate a means of pressurising the propulsion tanks with air. The design should present how the tanks would be pressurised and depressurised from a safe distance. Teams may be asked to display this during finals.

Only air is permitted as an inflation gas and no propellant other than water is permitted. This forbids the use of propellers, propulsive gas, engines and lighter than air gases such as helium.

The ratio of air-to-water inside the propulsion tank or tanks (not the payload tank) is customisable and should be exploited to optimise the performance of the vehicle.

The vector must be capable of being launched from a minimum of 5m away. Note that finalist teams may be asked to launch from further away depending on safety regulations of the site.

2.3    Control Mechanism

The design shall incorporate a means of controlling the descent of the vector to counteract the destabilising motion of the sloshing liquid. Details of how the sloshing liquid behaviour has been predicted and justification for the embodied solution shall be provided as part of the design submission. This could be achieved by using passive or active means or a combination of both:

• Passive Control: e.g., baffles. Any singular baffle inside the tank cannot cover more than 50% of the cross-sectional area of the
• Active Control: g. control surfaces.

2.4    Electronics and Additional Technology

An altimeter will be provided to the teams during the finals in order to measure the maximum altitude achieved during flight. The specifications for the model of altimeter used for the competition can be found in Appendix B.

Teams will not be given the altimeter in advance but will instead design a mounting location for it. The altimeter will then be given to teams prior to launch. The mounting and zeroing of the device will be monitored by judges to ensure accurate use.

The specific location of mounting is up to the discretion of the team. Note that the altimeter operates using air pressure sensors and therefore if placed inside the rocket (eg. in the section of the vector opposite to the nozzle), at least three evenly spaced 3mm square or round vent holes must be drilled to allow for a reading of the atmospheric pressure. It is recommended that the placement of these holes avoid high or low pressure areas. Note that if the altimeter does not have adequate airflow, a lower altitude reading will be shown.

The design of the vector should include solutions to maintain the altimeter fixed to its position and reduce the risk of the damaging or loss of the equipment. Penalties will be applied for the damage or loss of the altimeter.

2.5    Materials and Costs