Article: 0993
by Marty Weiser, November 2009

Suggestions for Team America Rocketry Challenge

  • Start Early.
  • KISS – Keep It Simple Stupid.
  • Don’t change anything by accident.  Record all changes once you start testing.  Even small changes can make a big difference in the altitude or duration. For example, not all eggs of the same size weigh the same.
  • Think about recovery first, second, and third. Then the other aspects of the design and flight
  • Launch using a rail since this will give a much straighter and consistent launch. I suggest a 6 foot long piece of the 1” square. McMaster-Carr PN 47065T122 is approximately $20, but there may be other local vendors. You will probably need to take a rail and pad to Nationals, but if it is split into two 3 foot sections it can be boxed up quite compactly. Plastic rail buttons are easy to machine on a metal lathe or can be purchased from
  • Use positive motor retention.  Do not rely on tape around the motor since kicking out the motor normally means the chute/streamer does not deploy.  Engine hooks work well for most of the motors used for TARC, but there are other options as well.
  • Build a strong, reliable rocket. You want to be able to conduct several test flights on the same rocket to determine how it performs and if you need to make changes. Suggestions include:
    • Aircraft or baltic birch plywood fins, bulkheads, and centering rings.  Use through the body tube fin mounting to the motor mount(s).
    • Wood or molded plastic nose cone vs. rolled cardboard.
    • Nylon or at least a reinforced plastic parachute/streamer. Use a Kevlar or Nomex chute protector.
    • Kevlar and/or nylon recovery harness. Do not use elastic. Make sure there is nothing in the body tube for the chute/streamer/harness to get caught upon.
    • Mount your altimeter or have it fit into a compartment that is just the right size. Make certain that it recovers safely – it is the most expensive component.
    • Design the rocket to fly higher than needed. You can always add weight to reduce the altitude.  Make sure the added weight cannot shift during flight.
    • Design the rocket to be stable, but not overstable. An overstable rocket with weathercock into the wind reducing both the altitude and time to landing.
    • Use a bridle or zipperless fincan to reduce the chance of zippering. Make sure the upper airframe is heavy enough to pull out the chutes if you go zipperless.
  • A lightweight rocket can be launched on smaller and cheaper than competition motors to gain experience. It can be launched both with and without the egg to collect data. Motor mount adapters are fairly easy to buy or make.
  • Buy or make some very good igniters. It is very frustrating to have igniter failures at the pad and lose your good weather window. It can be disastrous during the launch of clustered motors.
  • Run one or more Designed Experiments (DOEs) in the simulation software to explore how changing components and/or launch conditions impact the results. Use a DOE instead of one factor at a time (OFAT) to include interactions between the inputs.
  • Conduct several flight tests under different conditions before you attempt to qualify. Many of these flights can be done on smaller motors. Record the conditions and results. Download and analyze the data if possible.