Challenges and Benefits of Quantum Sensors for Inertial Navigation in Space

Inertial navigation is essential for space missions due to its independence from external signals and references. Inertial navigation systems (INS) rely on accelerometers and gyroscopes to track changes in velocity and orientation, allowing spacecraft to determine their trajectories independently—provided that gravitational accelerations are sufficiently well modelled. However, conventional electrostatic accelerometers used in current space missions typically suffer from significant low-frequency noise and drift, particularly below 10⁻³ Hz, which limits long-term navigation accuracy and orbit determination performance. Quantum inertial sensing based on atom interferometry, on the other hand constitute an attractive alternative technology, based on a fundamentally different measurement principle. By exploiting the wave nature of matter, quantum sensors enable highly precise and drift-free measurements of non-gravitational acceleration, with the potential to substantially improve orbit determination. In addition, the microgravity environment in space allows for interrogation times that are orders of magnitude longer than on Earth, leading to significantly enhanced sensitivity compared to terrestrial implementations of quantum sensors.

In this work, we present our developed,  comprehensive model for multi-axis quantum accelerometers and gyroscopes based on the schemes which are expected to perform best under the microgravity conditions of space. In particular, our modelling accounts for different sources of noise and systematics such as the detection noise, laser frequency noise, wavefront aberration, and sources of contrast loss. It also considers the combined effect of spacecraft rotation around all its axes, gravity gradients, and self-gravity on the measurements of the sensors. Using this framework, we simulate quantum inertial sensor measurements for Earth-orbiting satellites and along an Earth–Moon transfer trajectory, enabling an assessment of their performance for Earth-orbiting and lunar mission scenarios. The resulting simulations are used to evaluate the performance of quantum accelerometers and gyroscopes under different assumptions and scenarios in space. The goal of this work is to identify the challenges associated with deploying quantum inertial sensors for space navigation, to discuss potential mitigation strategies, and to quantify the benefits these sensors could provide for future spacecraft navigation and orbit determination.