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Maximum aerodynamic pressure of a spacecraft is the maximum force it's hull can withstand during flight. How is the Max-Q of a spacecraft determined?

Other related ( optional) queries are:

  • If Max-Q is also measurable on the ground, how are the simulated external forces applied to the DUT( Device Under Test)?

  • Which part of the craft is most vulnerable to such aerodynamic stress?

seccpur
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    Please, ask one question per question. If you have multiple questions, ask multiple questions. Your first question seems to have a rather simple answer, though: aerodynamic pressure is force pushing against the vehicle. You test it by pushing against the vehicle. – Jörg W Mittag May 08 '21 at 05:39
  • @Jörg W Mittag: Thanks. Thought the short piecemeal questions will spam here. – seccpur May 08 '21 at 05:49
  • @seccpur I've edited the question to make it clearer that you are asking about the maximum aerodynamic pressure a spacecraft can withstand, and not asking about MaxQ (the maximum (peak) dynamic pressure a rocket actually experiences during launch. I think the three questions are so closely related that supporting sources that answer one have a good chance of answering the other two as well. – uhoh May 08 '21 at 06:45
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    @JörgWMittag a careful reading of the original question shows that the OP was not really asking about MaxQ, but instead asking about testing for the maximum dynamic pressure that a rocket can actually experience before failure. Within this context I think the three aspects of the question are suitable for answering all together and probably don't need to be separated out into three different questions. – uhoh May 08 '21 at 06:47
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    A lot of modeling and simulation is done beforehand to predict stress/vibration loads from the chosen design. – Paul May 08 '21 at 13:16
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    @JörgWMittag How is the force applied to the vehicle structure? – Russell Borogove May 08 '21 at 17:11
  • Hey, that's an excellent question. Now I want to know too. How exactly do we test for the max dynamic pressure a rocket can bear? –  May 08 '21 at 18:55
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    If the question is asking "Does the actual vehicle structure get tested to max q on the ground" the answer is no. – Organic Marble May 08 '21 at 20:07
  • @RussellBorogove I think that's a fair interpretation of the question, but let's find out! – uhoh May 09 '21 at 03:45
  • @seccpur Is that a fair interpretation of the question? (see above) – uhoh May 09 '21 at 03:46
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    @uhoh: That's definitely fair interpretation of the question. Can the data be deduced from wind tunnel experiments at high velocity? – seccpur May 09 '21 at 04:14
  • @seccpur there are several ways to phrase your question: 1) "How is X tested on the ground?" 2) "Has X ever been tested on the ground, if so, how?" 3) "How to engineers know or at least estimate X? Are wind tunnels ever used to validate these models in some way?" I recommend rewriting your question to look more like #3 in order to generate some interesting and informative answers. Based on those, you can always ask several follow-up questions. We can ask as many questions as we like in SE, and we get the best results when we "fine tune" them to bring out some excellent answers. – uhoh May 09 '21 at 04:18
  • What is a "DUT"? – Organic Marble May 09 '21 at 12:28
  • Device Under Test – seccpur May 09 '21 at 13:00
  • Max Q is determined by preflight numerical simulation. All you need is the speed of the vehicle and its altitude (to get the ambient pressure). see https://space.stackexchange.com/q/49477/6944 – Organic Marble May 09 '21 at 13:07
  • @Organic Marble: Thanks for the link. SpaceX is likely to use a jig in the test nose cone perhaps for test on the ground, so I am interested in this alternative also. – seccpur May 09 '21 at 13:33

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