Dave5

Their proposal calls for a 100-gigawatt (GW) laser beamer boosting thousands of gram-scale space probes with laser sails to relativistic speed (~10-20 percent of light). They also proposed a series of terrestrial light buckets measuring a square kilometer (0.386 mi²) in diameter to catch the light signals from the probes once they are well on their way to reaching Proxima Centauri (and communications become more difficult).

By their estimates, this mission concept could be ready for development around midcentury and could reach Proxima Centauri and its Earth-like exoplanet (Proxima b) by the third quarter of this century (2075 or after).

https://www.sciencealert.com/nasa-selects-a-wild-plan-to-swarm-proxima-centauri-with-thousands-of-tiny-probes