Embedded cold atom accelerometer for atmospheric drag measurement

Below 600 km, drag is the largest source of uncertainty for satellite and debris orbit prediction. With an increasing number of satellites in low-Earth orbit, accurate observations of the atmospheric mass density are required to improve models of the thermosphere with applications in satellite lifetime predictions, collision risk assessment and avoidance. We are developing a compact cold atom accelerometer for atmospheric density missions, to be launched in mid to late 2020s. These quantum sensors are based on atom interferometry. A cold atom sample is generated using the combination of an atom-chip and resonant laser beams. The cold atom cloud is then diffracted using a set of three laser pulses, generating a matter-wave interferometer. The phase-shift at the output of the interferometer is proportional to the acceleration of the free falling atoms with respect to the satellite, which is converted to density observations. Teledyne e2v is producing a space suitable accelerometer physics package that can be embedded in small satellites such as a 16U cubesat or a SkimSat. It includes an atom-chip for producing magnetic fields local to the atoms in vacuum developed by RAL Space. It will address some of the engineering challenges associated with the launch and the required low SWAP and will be integrated into a breadboard system capable of acceleration measurement in order to test interferometry schemes suitable for measurements in micro-gravity. Atmospheric drag measurement can be the world’s first cold atom Earth observation mission and be a pathfinder for a future large-scale cold atom gravity mission.