In 50 years it would be some 41bn kms away (it travels at a speed of 26km/s). Say you want to reach it within a five year span that would mean we'll need to build a spacecraft that could travel 0,1% the speed of light. Probably within our future capabilities considering all the theories that have been proposed for interstellar travel. For example the Breakthrough Starshot project has predictions for 10%-20% of the speed of light.
Of course reaching it and landing on it, especially at these speeds, are two completely different things.
We could revive Project Orion[1] and use up some of the world's nukes in a productive way. If there was high confidence that ’Oumuamua was an alien constructed object, I would support it.
Of course reaching it and landing on it, especially at these speeds, are two completely different things.