NASA Develops First Space-Based Quantum Sensor to Create Most Accurate Map of Earth’s Gravity

NASA scientists published an article in the journal EPJ Quantum Technology, in which they reported the development of the first space quantum sensor for measuring gravity near Earth. The new device will be able to create a gravity map of the planet with the highest accuracy. This will help in navigation, in space programs, and will also allow remote determination of mineral deposits, including oil and drinking water.

An example of a gravity map of Earth (red indicates areas of high gravity, blue indicates low gravity). Image source: NASA

Quantum gravity sensors use the same principle of measuring gravity as conventional sensors, only they will be an order of magnitude more sensitive. To do this, quantum sensors use atoms as test masses, by the acceleration of which the gravity at a specific point in space is determined. Otherwise, everything happens in a similar way. Depending on the gravity at each specific point in space, the test mass will fall with greater or lesser acceleration. Thus, far below on the Earth and under its surface, over which the satellite with the sensor flies, either more or less mass will be concentrated.

The Quantum Gravity Gradiometer Pathfinder (QGGPf) uses super-cooled rubidium atoms as a test mass. Cooled to temperatures close to absolute zero, the particles in the clouds of atoms will behave like waves. The quantum gravity gradiometer will measure the difference in acceleration between the waves of this matter to detect gravitational anomalies.

NASA is collaborating with a number of companies and research centers to develop the QGGPf sensor and its satellite system. For example, the JPL team is developing the sensor head technology with AOSense and Infleqtion. NASA’s Goddard Center is working with Vector Atomic to improve the laser optical system.

The quantum sensor promises to be compact enough to be placed on board a relatively small ship. Its volume will be around 0.25 m³, and its mass will be about 125 kg. Traditional space-based gravity devices are noticeably larger and heavier.

The first flight tests of the quantum gravity sensor elements are planned for the end of the current decade. The launch date of a full-fledged quantum scientific instrument into space has not been set — there are still many technical barriers to overcome. In addition to compiling a gravity map of the Earth, the quantum sensor will help study the planets of the solar system and contribute to fundamental physics. In its field, it will become the most advanced and the first scientific instrument of its kind.