Hmm, Andromeda is 2,000,000+ lys away. At c, it would take 2mil years to get there. To do it in ten years would take a speed of millions of times c. Let's talk energy consumption, photons travel at c, why don't they consume infinite energy? Photons do have mass..very little, but they do have...
Seems to me that in the case of travel to andromeda, to travel there in 3 years would entail traveling at millions of times c. Andromeda is over 2,000,000lys away.