Ground testing is a critical step to take before launching a rocket. Ground tests help confirm (but cannot guarantee) that a recovery system is well designed, especially the size of pyrotechnic charges (or the effectiveness of other separation mechanisms). If you make any significant changes to your rocket after ground testing, you should always re-test. Testing can uncover a variety of unforeseen issues such as:

  • Too much force required to separate–for example, due to too many/too large of shear pins
  • Tubes binding (due to out-of-round tubes or too much friction) and not separating
  • Structural weaknesses–for example, loose bulkheads
  • Failure to pressurize due to leaks in a bay

Testing also provides integration practice and helps identify potential procedural improvements. The MIT Rocket Team conducted an extensive test campaign in the 2016-2017, which you can watch in this video compilation of 2016-2017 ground tests! As you can see in the video–our tests don't always work! Every failed ground test helps us avoid the associated problems during flight.

It is important that ground tests are conducted with the utmost safety for the sake of all participants and spectators. To set up a safe test, follow these steps:

  1. Identify a good location. You should visibly mark off a 25 foot perimeter around the testing location (for example, by using bright cones or signs). The MIT Rocket Team conducts its tests on a soft, grassy field. This prevents rockets from incurring damage when they hit the ground. Avoid areas of dry grass, which may be at increased risk of fire.
  2. Make sure you have permission to use the space and that you are complying by all laws. You may wish to send a safety plan to relevant authorities and get their permission. For example, the MIT Rocket Team always gets permission from the Athletics Department to use the sports field for ground testing. Our safety plan is also reviewed by the campus Environmental Health and Safety (EHS) department.
    1. The Team also calls a non-emergency police number prior to testing, to warn about potentially loud noises.
  3. Bring all of the necessary supplies for rocket integration onto the field. You may wish to integrate the rocket indoors, but you should leave pyrotechnics or other separation mechanisms uninstalled before arriving at the field.
    1. Integrate your rocket, making sure that all members use appropriate Personal Protective Equipment (PPE), especially when handling charges.
  4. Place the rocket horizontally on two or more small stands, which you can make out of PVC tubes. Make sure that the rocket is pointed away from all people and obstructions, even if they are outside of the 25 foot radius.
  5. Using either a long stretch of wire and a battery ora wireless control system such as AltOs software, ignite your charges in the correct order.
    1. Prior to igniting the charges, everybody (including test participants and pedestrians) must clear the 25-foot radius. Even outside of the radius, everybody should wear safety goggles.
    2. Perform a countdown prior to igniting the charges–speak loudly so that everybody nearby is able to hear.
    3. More details about how to connect wires and set up AltOs will be added–in the meantime, consult with an expert to ensure a safe and successful test.
  6. You may want to take video so that you can review it later.
  7. If the recovery mechanism does not fire, wait at least 60 seconds before approaching the rocket (with PPE) to evaluate the failure.

Because it is impossible to write out all possible safety concerns on this page, we recommend that you delegate someone to be Safety Officer. The Safety Officer should review your individual ground testing procedure extensively.

 

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