Manufacturing a new propulsion method mid journey

I have an interstellar ship going from earth to a nearby star system using current technology and chemical fuel. The ship has been created and is being managed by a self sufficient android.

The android has high levels of processing, learning capabilities and can re programme and upgrade itself. Equipped with all mankind's knowledge and proposed/theorised future technologies the android joined to the ships more powerful computers has thousands of years to run calculations to upgrade and create new machinery.

The ship has 3D printers than can be upgraded, electron welding and other manufacturing methods achievable on a ship roughly 50m length, 15m width (this size can be altered to fit the needs).

If enough manufacturing material can be brought to the ship for its initial stage, asteroid mining before the ship leaves the solar system is an option also, could the ship upgrade itself, its size and most importantly completely change its propulsion method to something far more efficient, cutting its 70 thousand ish year journey to a mere few thousand years or less?

I understand this question is theoretical methods and giving a scientific answer about a technology we haven't currently mastered might not be possible but I am after a plausable theoretical solution given the situation.

So my question is, with thousands of years of calculations, if sufficient materials and manufacturing processes were available (the ships size can be altered to accommodate this) what new propulsion method could be created, assembled and implemented mid journey?

posted over 4 years ago

RandySavage‭

21 reputation 35 0 4 0