Laser Cooling Assisted Thermal Management of Lightsails

A lightsail can be accelerated to ultra-high speed by the radiation pressure of a laser having an intensity order GW/m$^2$, which though presents critical challenge in thermal management lightsails. In this letter, we explore applicable regimes solid-state cooling dissipating heat additional previously explored radiative approach. We begin examining capacity cooling, and show that rate from micron-thick layer doped with ytterbium ions exceed blackbody emission. This allows more intense illumination upon material damage, consequently shortened acceleration distance. Next, impact limited operating bandwidth account for Doppler shift pumping laser, conclude is helpful target velocities $\lesssim5\%$ room-temperature operations.