National Aeronautics and Space Administration

The Polarimeter Light (PolarLight) mission is a technology demonstration instrument on-board a CubeSat named Tongchuan-1 (or Zhaojin 1 (TY 4-02)). It uses a gas pixel detector sensitive to polarized X-ray light. The satellite was launched into a sun synchronous polar orbit on October 28, 2018 and is currently still operating. Ths mission is led by the China Center for Astrophysics at Tsinghua University in Beijing, China.

PolarLight carries a Gas Pixel Detector (GPD) instrument filled with dimethyl ether at approximately 0.8 atmosphere pressure, and sealed with a 100 micron thick beryllium window. The detector has an effective area of 1.4 x 1.4 mm. The detector is mounted on a 6U size Cubesat for supporting electronics, power supply, data recording, and solar panels.

The GPD instrument has produced some preliminary results from observations of the Crab and Sco X-1 sources.