[plain talk]

Breakthrough Starshot is hoping to launch a small probe that would both depart much sooner and travel much faster, arriving as quickly as 20 years.

Breakthrough Starshot relies on a huge investment in ground based lasers. I do like the idea of extremely small robotic probes. However I am skeptical of their means of propulsion. By the time they could build something like this scientists would have come up with a better solution.

[Simon Green]

Breakthrough Starshot relies on a huge investment in ground based lasers

I recall the sf novel "Rocheworld" by Robert L. Forward in which the first manned starship is propelled to a quarter the speed of light using solar-powered lasers covering the surface of Mercury.