Streamline body shape is essential for reducing friction during motion in fluids like liquid and gas, including our dense atmosphere.

Is streamline body shape also essential for propagation in the vacuum of space for interplanetary voyage?

  • $\begingroup$ Do you only intend to voyage between the planets or also land on them? And if yes, do they have an atmosphere? $\endgroup$ Mar 27, 2021 at 10:28

1 Answer 1


No. Apollo's "lunar lander" is the most famous example of a nonstreamlined spacecraft. Grumman's engineers marvelled at how clumsy the fastest vehicle they'd ever designed looked.

This is because there is so little stuff in space, and therefore so little friction traveling through space that it's unneeded to take measures to reduce the friction there is.

As an analogy to streamlining, but because of thrust rather than drag, spacecraft prefer to keep mass near the center, i.e., near the line of thrust.

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    $\begingroup$ The title just asks about space, but the body of the question asks "...for interplanetary voyage?" I don't think that it makes any difference, but the lunar lander only traveled (by itself) between the surface and about 100 km. I don't think it it matters even for meteorites, since their relative velocities are such that they can come from any direction. $\endgroup$
    – uhoh
    Mar 26, 2021 at 16:40
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    $\begingroup$ Pioneer 10/11, Voyager 1/2, and New Horizons might be better examples. Or Dawn, which actually orbited more than one planetoid during its mission. $\endgroup$ Mar 26, 2021 at 16:53
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    $\begingroup$ Yes, better examples, but not so famous. The LL has appeared in videogames, several Lego sets, and who knows what else. $\endgroup$ Mar 26, 2021 at 17:25
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    $\begingroup$ The only thing I'd add to this answer is that if you wanted to use acceleration to simulate gravity, you're likely going to want a "stacked" sort of design, where different decks are all aligned more or less along one axis. Still not streamlined exactly, but not just all over the place either. $\endgroup$ Mar 26, 2021 at 18:09
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    $\begingroup$ @Innovine interstellar atoms would be high energy particle radiation from the perspective of a relativistic craft. Streamlining's not going to make a difference, more, any effect on the craft's trajectory via drag will mean dissipating a fraction of the craft's kinetic energy within the craft itself. It seems likely the radiation will be an issue before the drag becomes one. $\endgroup$ Mar 26, 2021 at 23:28

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