[marcosdumay]

About slowing down, it's pretty predictable. The idea is even to run the ship in constant acceleration.

I don't think you'll want to actually navigate that ship. It's a point and go task. But if needed, you rotate the ship and keep accelerating. But I have no idea on how much you'd be able to fix your route after you discovered it is wrong.

I think the main issues are how do we make a ship where people can live for decades? And how do we launch it from the ground?