your math dont hold up.
At 1.5% of light speed you cant reach a star that is several light years away in 17 years. If I remmeber correctly, Alpha Centauri is 3.7 light years, means at 1,5% light speed it would take about 300 years.
Also the "fly to mars" model has a significant error:
How do you brake?
If you have a laser that powers you by "bombarding" then what is stopping you?
Also I guess the g forces to make it in 3 days would be too high - several g permamently. But someone else can do the math on that.
Exactly that's the problem! The scientists haven't found a solution for a brake yet, like mentioned above.. that would be a VERY big problem if they don't come up with something to solve it, there would be absolutely nothing to stop the aircraft from crushing into another planet at full speed!
But obviously, this whole project is still very much a theory, and I'm not sure about the detailed numbers.
All I know is that this is an exciting idea, but there is still a LOT of work today if we want to see this come to life!