I just watched the movie 'Interstellar' for the first time. Assume we have reached the point (in real life) where we are able to launch interstellar spaceships meant to colonize other planets. To do this could we launch 3 or more ships from Earth and have them somehow link up or come together in space to form a larger ship, or would the ship need to be assembled in space because of how large it would have to be? I'm imagining the space station near the end of the movie could not be built on earth due to the size of it. The movie was very interesting and it got me thinking and I'm just curious. Thanks in advance.

Warning: minor spoilers in comments.

closed as primarily opinion-based by Phiteros, Nathan Tuggy, Hohmannfan, GdD, Rory Alsop Sep 6 '16 at 10:17

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  • Note a few things. 1) Interstellar actually became intergalactic. (I have no idea why they thought it was a good idea to call it Interstellar, it's not as if they reserved the intergalactic aspect of it as a 'major / shock reveal'.) 2) The ships seen, were not even capable of interstellar flight, they were just interplanetary craft - it was the wormhole that made all the difference in range. 3) "I'm imagining the space station near the end of the movie could not be built on earth due to the size of it." Were we watching the same (bad) movie? The whole point of getting the .. – Andrew Thompson Sep 6 '16 at 4:16
  • .. 'gravity equations' was so they could get the space stations off Earth. – Andrew Thompson Sep 6 '16 at 4:17
  • Apologies for the confusion. I know what happened in the movie. I was asking about how we would do it if it was really life and not in a movie. The movie was what got me thinking about this. – Henry D. Sep 6 '16 at 4:28
  • Well assembling large structures in space would be most efficient using materials sourced from shallow gravitational wells, like asteroids and comets but the thing is, we'd need a space mining industry. That probably won't happen for decades yet. OTOH There are some things like the ISS that were effectively built on Earth and assembled in space. Craft the size of the space stations seen at the end of Interstellar might not be made for centuries, and the best way to make them would depend on the available technologies. Speculating now about those technologies would be pointless. .. – Andrew Thompson Sep 6 '16 at 4:50
  • .. Think people in Europe just after Columbus returned in the 15th century speculating on the best way to visit the United States for holidays. Would they even consider machines that could fly there, like a bird? – Andrew Thompson Sep 6 '16 at 4:52

With our current understanding of physics, YES we would have to build it in space.

There is no way we can scale rockets so high as to build large spacecraft and launch from Earth. Of course, as comments pointed it out, it might be beneficial to build the rocket from off-Earth resources, avoiding the launch from Earth issue in the first place.

Realistically, engineering and R&D could only scale payload to LEO in the order of thousands of tonnes.

Not directly related but to give you and idea of how badly rocket scales:

How much bigger could Earth be, before rockets would't work?

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