Interstellar ships will be shaped like pencils to deflect rather than impact gasses. They will also have to have consumable nose cone sections with old ones in the front being removed and new ones installed at that back. Like a mechanical pencil.
[1] https://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth
Engines used in such long journeys will likely emit a thin stream of particles at extreme velocities. This stream is not wide enough or thick enough to stop space dust from hitting the engine. An unshielded forward-facing engine will get destroyed. So we must shield the engine.
Instead of having two shields and turning the ship around, just turn the engine around. Make the engine emit streams forward from the sides of the ship.