Quantum various to GPS navigation will probably be examined on US army spaceplane

A US army space-plane, the X-37B orbital check car, is because of embark on its eighth flight into area on August 21 2025. Much of what the X-37B does in area is secret. But it serves partly as a platform for cutting-edge experiments.

One of those experiments is a possible various to GPS that makes use of quantum science as a instrument for navigation: a quantum inertial sensor.

Satellite-based programs like GPS are ubiquitous in our each day lives, from smartphone maps to aviation and logistics. But GPS isn’t obtainable in all places. This expertise might revolutionise how spacecraft, airplanes, ships and submarines navigate in environments the place GPS is unavailable or compromised.

In area, particularly past Earth’s orbit, GPS indicators turn into unreliable or just vanish. The similar applies underwater, the place submarines can not entry GPS in any respect. And even on Earth, GPS indicators will be jammed (blocked), spoofed (making a GPS receiver suppose it’s in a distinct location) or disabled – as an illustration, throughout a battle.

This makes navigation with out GPS a essential problem. In such situations, having navigation programs that operate independently of any exterior indicators turns into important.

Traditional inertial navigation systems (INS), which use accelerometers and gyroscopes to measure a car’s acceleration and rotation, do present unbiased navigation, as they will estimate place by monitoring how the car strikes over time. Think of sitting in a automotive along with your eyes closed: you may nonetheless really feel turns, stops and accelerations, which your mind integrates to guess the place you might be over time.

Eventually although, with out visible cues, small errors will accumulate and you’ll solely lose your positioning. The similar goes with classical inertial navigation programs: as small measurement errors accumulate, they progressively drift off track, and wish corrections from GPS or different exterior indicators.

Where quantum helps

If you consider quantum physics, what might come to your thoughts is an odd world the place particles behave like waves and Schrödinger’s cat is each useless and alive. These thought experiments genuinely describe how tiny particles like atoms behave.

At very low temperatures, atoms obey the principles of quantum mechanics: they behave like waves and might exist in a number of states concurrently – two properties that lie on the coronary heart of quantum inertial sensors.

The quantum inertial sensor aboard the X‑37B makes use of a method known as atom interferometry, the place atoms are cooled to the temperature of close to absolute zero, so that they behave like waves. Using fine-tuned lasers, every atom is break up into what’s known as a superposition state, much like Schrödinger’s cat, in order that it concurrently travels alongside two paths, that are then recombined.

Since the atom behaves like a wave in quantum mechanics, these two paths intrude with one another, making a sample much like overlapping ripples on water. Encoded on this sample is detailed details about how the atom’s setting has affected its journey. In specific, the tiniest shifts in movement, like sensor rotations or accelerations, go away detectable marks on these atomic “waves”.

Compared to classical inertial navigation programs, quantum sensors supply orders of magnitude larger sensitivity. Because atoms are equivalent and don’t change, in contrast to mechanical parts or electronics, they’re far much less susceptible to drift or bias. The result’s lengthy length and excessive accuracy navigation with out the necessity for exterior references.

The upcoming X‑37B mission would be the first time this stage of quantum inertial navigation is examined in area. Previous missions, comparable to Nasa’s Cold Atom Laboratory and German Space Agency’s MAIUS-1, have flown atom interferometers in orbit or suborbital flights and efficiently demonstrated the physics behind atom interferometry in area, although not particularly for navigation functions.

By distinction, the X‑37B experiment is designed as a compact, high-performance, resilient inertial navigation unit for actual world, long-duration missions. It strikes atom interferometry out of the realms of pure science and right into a sensible utility for aerospace. This is a giant leap.

This has essential implications for each army and civilian spaceflight. For the US Space Force, it represents a step in the direction of larger operational resilience, significantly in situations the place GPS is perhaps denied. For future area exploration, comparable to to the Moon, Mars and even deep area, the place autonomy is vital, a quantum navigation system might serve not solely as a dependable backup however whilst a major system when indicators from Earth are unavailable.

Quantum navigation is only one half of the present, broader wave of quantum applied sciences shifting from lab analysis into real-world purposes. While quantum computing and quantum communication typically steal headlines, programs like quantum clocks and quantum sensors are prone to be the primary to see widespread use.

Countries together with the US, China and the UK are investing closely in quantum inertial sensing, with current airborne and submarine exams exhibiting sturdy promise. In 2024, Boeing and AOSense carried out the world’s first in-flight quantum inertial navigation test aboard a crewed plane.

This demonstrated steady GPS-free navigation for about 4 hours. That similar yr, the UK carried out its first publicly acknowledged quantum navigation flight test on a business plane.

This summer time, the X‑37B mission will convey these advances into area. Because of its army nature, the check might stay quiet and unpublicised. But if it succeeds, it may very well be remembered because the second area navigation took a quantum leap ahead.