Ping Pong Parachute Fundamentals
What is ping pong parachute
Ping pong parachute is an engineering-based event hosted by Science Olympiad where students are tasked to build and test a bottle rocket indoors that deploys a parachute that holds a ping pong ball. The objective to achieve the highest time aloft for the ping pong ball. These concepts also apply to Indoor Bottle Rocket, another event held by Science Olympiad.
In this post, we will outline the basic concepts needed to consider when creating a ping pong parachute device and how to optimize those aspects of your device for the best results.
what to consider
Rocket Weight
Because you are only limited to 60 psi to launch your bottle rocket, you should make an effort to keep your bottle rocket light so that the bottle rocket can reach the ceiling of the testing site. The lighter your rocket is, the higher it will launch.
Because you are confined to use a 1 liter bottle the only components that you can truly alter are the rocket fins and the rocket fuselage. For rocket fins, I would advise using extremely thin plastic (between 0.010″ and 0.020″) as it is extremely light but still sturdy enough to survive high pressure launches and hard falls. For the rocket fuselage, many teams will use cylindrical ceiling light tubes, which can be an effective material but only with some modifications: the entire tube is not necessary so I would advise cutting off part of the tube and sanding the inside of the tube to reduce weight. However, if you are skilled with rolling balsa tube, it can be even more effective to simply make the fuselage from rolling a sheet of balsa wood.
Parachute weight
Parachute weight is the MOST IMPORTANT factor to consider when designing your device. This is because if the parachute weighs more than the ping pong ball (~3g) then the parachute of your device will not properly deploy. Therefore, it is extremely important that you minimize the weight of your parachute to achieve the best results.
Parachute diameter
When constructing your device, it is important to maximize the the parachute diameter because the larger your parachute diameter is, the more drag force your device will have, in turn, increasing the device’s time aloft. However, it is important to note that increasing your parachute diameter will increase parachute weight. Therefore, you must balance parachute diameter with parachute weight.
rocket length
The deployment mechanism refers to the parachute, ping pong ball, and string that combines both of them.
It is best to keep your rocket’s length slightly larger than the the length of your rocket’s deployment mechanism because when you launch your rocket, a larger rocket length will prevent any tangling or malfunction of your deployment mechanism.