The POLAR-2 Gamma-Ray Burst (GRB) Polarimetry mission is a follow-up to the successful
POLAR mission. POLAR collected six months of data in 2016-2017 on board the Tiangong-2
Chinese Space laboratory. From a polarization study on 14 GRBs, POLAR measured an overall
low polarization and a hint for an unexpected complexity in the time evolution of polarization
during GRBs. Energy-dependent measurements of the GRB polarization will be presented by
N. de Angelis in GA21-09 (August 2nd). These results demonstrate the need for measurements
with significantly improved accuracy. Moreover, the recent discovery of gravitational waves and
their connection to GRBs justifies a high-precision GRB polarimeter that can provide both high-
precision polarimetry and detection of very faint GRBs. The POLAR-2 polarimeter is based on
the same Compton scattering measurement principle as POLAR, but with an extended energy
range and an order of magnitude increase in total effective area for polarized events. Proposed and
developed by a joint effort of Switzerland, China, Poland and Germany, the device was selected
for installation on the China Space Station and is scheduled to start operation in 2025.