You would think that with the quest for aerodynamic efficiency in current spacecraft that the nose-cones at the pointy end of the launch-vehicle would have a sharp taper, more so for craft that aren't going to re-enter the atmosphere.

However this doesn't appear to be the case. Why?

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    $\begingroup$ There are other considerations: a sharp cone needs to be much longer to fit over the spacecraft, so you get more drag and weight from the extra area. $\endgroup$
    – Hobbes
    Commented Jan 17, 2016 at 19:37
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    $\begingroup$ I believe there is also an issue with shockwaves once the rocket goes supersonic. I don't recall details, though. $\endgroup$ Commented Jan 17, 2016 at 19:51
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    $\begingroup$ I believe guys at aviation.SE could explain it in details, but sharp nose cone is not always optimal aerodynamically. In particular, IIRC, when you create a smooth flow along a smooth slope of the nose, it creates a vacuum area after the nose straightens out into the main hull. This vacuum was known to literally rip the coating off airplanes, but besides the structural concerns it creates more drag than a blunt nose cone that forces the air around the rocket evenly. $\endgroup$
    – SF.
    Commented Jan 18, 2016 at 0:51
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    $\begingroup$ ...in particular, aviation.stackexchange.com/questions/24414/… $\endgroup$
    – SF.
    Commented Jan 18, 2016 at 2:48
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    $\begingroup$ @SF. With 100% certainty, there are no smooth ("laminar") supersonic flows. $\endgroup$ Commented Dec 10, 2018 at 21:01

1 Answer 1


The blunt nose produces a shock wave which diverts heat away. The sharp tip you envisage would stick out in the hypersonic air stream and melt right off.

  • $\begingroup$ This is true for reentry vehicles that have to withstand much higher dynamic pressure, not so much for launch vehicles with max q at a bit over Mach 1, as the question asks about. $\endgroup$
    – TildalWave
    Commented Jan 18, 2016 at 5:21
  • $\begingroup$ Where demands are lower (no high velocity reentry), there's probably a four-way balance between drag, heating, cost, and strength. The final shape is a compromise of many variables. $\endgroup$
    – Saiboogu
    Commented Dec 10, 2018 at 20:43
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    $\begingroup$ @Saiboogu add weight to the list $\endgroup$ Commented Dec 10, 2018 at 21:02
  • $\begingroup$ Thanks for that reference. It explains the case for re-entry vehicles. There are so many more points that are important to a complete answer, not only those addressing expendable spacecraft, that I somehow feel this answer is incomplete at the moment. $\endgroup$ Commented Dec 10, 2018 at 21:07

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