LSPE-SWIPE

LSPE-SWIPE (for Large-Scale Polarization Explorer/Short Wavelength Instrument for the Polarization Explorer) is a planned 50 cm balloon-borne telescope to survey CMB polarization. The plan is to use transition edge sensor (TES) bolometers operating at 0.3 K, centered on three frequencies, 140 GHz, 220 GHz, and 240 GHz. The plan is to survey 20% of the sky in a ~15-day flight. The most recent news I've found said the first flight was planned for the Winter of 2022-2023.