A recent research discussion paper "The Andromeda Study: A Femto-Spacecraft Mission to Alpha Centauri" discusses options for a 50 year (at 0.1c) one-way, fly-by, exploration trip to our nearest stellar neighbour, Alpha Centauri. In the paper the authors (Andreas M. Hein, Kelvin F. Long, Dan Fries, Nikolaos Perakis, Angelo Genovese, Stefan Zeidler, Martin Langer, Richard Osborne, Rob Swinney, John Davies, Bill Cress, Marc Casson, Adrian Mann, Rachel Armstrong) discuss the challenges and present possible solutions using current science and technology.
They propose a femto craft (23g) powered by a space-based laser with a beam output of 15GW, and report that "further exploration of the laser-spacecraft trod-space and associated technologies are necessary".
After the 50-year trip the exploration data would be sent back to the Solar System.
SpaceRef reported... "The results show that by extrapolating from currently existing technology, such a mission would be feasible. The total mass of the proposed spacecraft is 23g and the space-based laser infrastructure has a beam power output of 15GW. Rurther exploration of the laser - spacecraft tradespace and associated technologies are necessary."
Further reading here:
The full discussion paper is here:
The Abstract of the paper is here:
The Author's FaceBook page is here: