Starshot (or Breakthrough Starshot) is a speculative initiative to
develop a mission to fly space probes by Alpha Centauri.
(It is one of the Breakthrough Initiatives, projects
in the area of SETI and astrobiology.)
A fleet of very small (centimeter-sized) craft (StarChips)
would be propelled by ground-based lasers.
The initiative began in 2016, aiming to reach (ideally) 20% of the
speed of light, potentially reaching the system in 20 years. Since
communication home would be light-speed,
it would take four additional years before data was received at Earth.
In 2017, tiny satellites (given the name Sprites), were deployed
to test the concept of centimeter-sized spacecraft.