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?
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?
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.