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    <p>Do you want answers (or attempts at answers) on the list or
      direct to you?</p>
    <p><br>
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    <p>-Zach, KJ4QLP<br>
    </p>
    <pre class="moz-signature" cols="72">Research Associate
Aerospace Systems Lab
Ted & Karyn Hume Center for National Security & Technology
Virginia Polytechnic Institute & State University
Work Phone: 540-231-4174
Cell Phone: 540-808-6305</pre>
    <div class="moz-cite-prefix">On 6/8/2018 10:36 PM, Michelle Thompson
      via Ground-Station wrote:<br>
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                          <div>Phil Karn KA9Q has been working on
                            something fun for us. If you enjoy this
                            quiz, please feel free to share it and let
                            him know!</div>
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                          <div>Given the documents that you can find at:
                            <a
                              href="https://github.com/phase4space/AO-10-blueprints"
                              moz-do-not-send="true">https://github.com/phase4space/AO-10-blueprints</a></div>
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                          <div>Quiz for fans of the AMSAT Phase
                            IIIB/AO-10 blueprints</div>
                          <div>Phil Karn, KA9Q</div>
                          <div><br>
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                          <div>Question 1: AO-10 carried a 400-newton
                            kick (rocket) motor that used hypergolic
                            propellants. It was fired only once, but the
                            burn duration was 1.68 times longer than
                            planned. Why? (Note: the burn did *not* end
                            because of propellant depletion.)</div>
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                          <div>The cause can be discerned from the
                            prints; i.e., it was a hardware problem, not
                            a software bug or operational mistake.</div>
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                          <div>Optional hint 1: The burn was timed in
                            hardware.</div>
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                          <div>Question 2: The ground test of the
                            hardware consisted of successfully executing
                            a maximal length burn. What tests could have
                            revealed it?</div>
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                          <div>Question 3: Although the first burn did
                            not deplete the propellants, it was not
                            possible to fire the engine again because of
                            insufficient helium pressure. Why? (Hint:
                            the cause was not insufficient helium
                            loading before launch.)</div>
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      <pre wrap="">_______________________________________________
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</pre>
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