Aerotech D21-4T CATO?

Discussion in 'Low Power Rocketry (LPR)' started by jnmiller, Oct 10, 2018.

  1. Oct 10, 2018 #1

    jnmiller

    jnmiller

    jnmiller

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    I'm not sure what happened here. I have a Semroc Mars Lander with an Aerotech D21-4T. This is a disposable motor. On countdown as soon as the button is pushed, it appears the ejection charge fires immediately. There is no normal thrust at all, or even delay. If you look closely, the engine actually ejects out the aft of the rocket getting past the engine hook. It destroys a ceramic tile blast deflector on the way. I think that was the only damage. The rocket still looks good. I am looking for ideas on what happened ??!?

    Here's a link
     
  2. Oct 10, 2018 #2

    Rex R

    Rex R

    Rex R

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    we will need to see the motor. obviously there was a problem with fire reaching the ejection charge early, however the 'why' is a mystery.
    Rex
     
  3. Oct 10, 2018 #3

    Nytrunner

    Nytrunner

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    And please file a MESS report.

    Anyone know if D21s are still in production? (or are vendors just working through their stock)
     
  4. Oct 10, 2018 #4

    shreadvector

    shreadvector

    shreadvector

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    Possibly blew the forward end of the motor. Need to see detailed photos of the motor corpse.

    This can happen if there is a manufacturing defect (forward delay housing not epoxied in properly) or if the user installs an igniter that clogs the nozzle and causes and overpressure.
     

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