Researchers from the Chinese Academy of Sciences have deployed the China Space Station Atom Interferometer (CSSAI), the first operational cold atom gyroscope in orbit. The system uses laser-cooled rubidium-87 atoms and atom interferometry to measure rotational and acceleration forces with high precision. Single-experiment results show a rotation resolution of 50 μrad/s and acceleration resolution of 1.0 μm/s². With integrated data, long-term rotation resolution improves to 17 μrad/s. These values were cross-validated with the station’s classical gyroscopes and found to match closely.
The CSSAI payload, measuring 46×33×26 cm and operating at 75 W, applies a shearing interferometry technique with optimized “magic angle” laser configurations to cancel fringe dephasing. The research team analyzed error contributions from imaging, magnetic fields, atom cloud parameters, and laser stability. The shearing angle was identified as the main contributor to systematic uncertainty. The atom interferometer supports microgravity-based quantum inertial sensing with greater sensitivity than mechanical or optical systems used in prior missions such as Gravity Probe B and LARES.
This development marks a transition to quantum-based inertial sensors for potential use in navigation and general relativity tests. The CSSAI is part of China’s broader strategy for integrating quantum technologies into space systems. Future research will target further miniaturization, error reduction, and robustness for deployment in spacecraft, satellites, and long-duration missions.
Read more in the official publication in National Science Review here and the supporting announcement from Science China Press here.
May 16, 2025
