LiteBIRD satellite: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization

In May 2019, LiteBIRD was selected as JAXA’s strategic L-class satellite #2 targeting a launch in 2020s with a H3 rocket. Its mission is to map the polarization of the cosmic microwave background (CMB) over the full sky at large angular scales with unprecedented precision. LiteBIRD will allow us to make a crucial test of cosmic inflation and quantum gravity theories behind it. It will also provide us with valuable information on astrophysics. Full-sky surveys for three years at a Lagrangian point L2 will be carried out for 15 frequency bands between 34 and 448 GHz with three telescopes to achieve the total sensitivity better than 3 microK-arcmin with a typical angular resolution of 0.5 degree at 150 GHz. We describe the conceptual design of LiteBIRD, including the polarization modulation unit, telescopes and optics, focal planes and cryogenic system. Calibration plans and strategies for minimizing systematic uncertainties and foreground contamination will also be explained.