Grapefruit-Sized Quantum Device Maps Earth’s Magnetic Field From Space Station

A quantum magnetometer the size of a grapefruit has demonstrated the ability to map Earth’s magnetic field from the International Space Station. The device, known as OSCAR-QUBE, measures 10 centimeters on each side. It relies on defects in a lentil-sized diamond to function as a sensor.

The instrument operated consistently during a 10-month period in 2021 and 2022, according to a paper published May 7 in Physical Review Applied. Its readings agreed with prior estimates of the magnetic field strength. Traditional space-based magnetic field measurements usually depend on bulky satellites.

Quantum sensors can be smaller while offering greater sensitivity and operational stability.

How the Diamond Sensor Works The sensor uses a piece of diamond containing defects in its carbon lattice, where a carbon atom is absent and replaced by a nitrogen atom in a neighboring position. These defects behave like quantum particles with distinct energy levels.

Changes in Earth’s magnetic field alter those energy levels. Variations in field strength are detected by shining laser light and microwaves on the diamond and measuring the emitted light. “Earth’s magnetic field is actually very fascinating to measure, because it contains a lot of information,” an engineer from Hasselt University in Belgium stated.

Motions in Earth’s molten outer core, crustal rocks, space weather and ocean tides all influence the field. Maps produced from such measurements can support navigation in environments where GPS is unavailable. The station-based device did not surpass the performance of the most advanced conventional magnetometers.

Internal magnetic fields inside the station limited its accuracy.

A future mission will use upgraded quantum hardware. The new sensor will operate from outside the space station to avoid interference from the station’s own magnetic environment. The initial results indicate that compact quantum magnetometers can function reliably in orbit over extended periods.