Anyone who’s ever had to use their favorite navigation app to go around has taken advantage of the benefits imparted to us by the global positioning system, better known as GPS.
Using a network of satellites scattered across our skies, GPS has allowed us to locate ourselves on this planet with unprecedented precision. Since its development by the United States’ government back in 1973, GPS has since played a crucial role in world logistics and traveling, from family cars to airplanes and the largest cargo ships.
However, given that GPS technology is now close to 50 years old, it has become a mission for some scientists to develop alternatives to current GPS systems. One particular limitation of this technology is its inability to function without the help of all those GPS satellites orbiting Earth. This is a concern to experts, given that GPS signals have a certain susceptibility to both spoofing and jamming.
A vacuum chamber technology alternative is available, however. Having been derived from technology designed for military rockets during World War II, it is also currently in use in submarines trying to find their way through the sea. Officially called inertial guidance, it uses gyroscopes and accelerometers that enable the device to determine with relative accuracy where its user is with respect to a designated fixed point.
Problem is, much like standard GPS, inertial guidance also necessitates high precision as well as a level of timekeeping that’s similar to the precision delivered by the atomic clocks used in GPS. Technology currently exists that can address these timekeeping issues, but solutions necessitate “heavy and expensive” vacuum systems.
Now, new research by Sandia National Laboratories (SNL) aims to bridge that gap by producing a potential GPS device which is independent of the GPS network entirely. Their new development encompasses the use of an avocado-sized vacuum chamber whose walls are made of titanium and sapphire, and their findings were published in the journal AVS Quantum Science.
The novel development is the latest in efforts to “move quantum sensors—sensors that use quantum mechanics to outperform conventional technologies—from the lab into commercial use,” according to SNL scientist Peter Schwindt in the institution’s press release.
The new vacuum system was constructed by placing quantum sensors in a cubic-centimeter volume (1 cm3; 0.06 in3). Then, the small chamber is evacuated to eliminate unwanted effects imparted by free atoms in any gases present inside. The vessel itself is made of titanium, and its windows are made of sapphire—two materials chosen for their capacity to prevent gases from leaking into the small cavity within.
Said SNL postdoctoral scientist Bethany Little in the SNL news release: “Quantum sensors are a growing field, and there are lots of applications you can demonstrate in the lab. But when you move it into the real world there are lots of problems you have to solve.”
The sensor system contained within the vacuum consists of a laser that shines through a cloud of rubidium (Rb) gas. When deployed with the right set of electronics, this setup is capable of detecting both rotation and acceleration, much like the standard GPS systems the new technology is trying to supersede.
Future work by SNL scientists aim at keeping and holding the vacuum for five (5) years; meanwhile, they will “[explore] ways to streamline manufacturing,” like making the device less cumbersome for production.
(For more uses with lasers, check out the next step in nuclear fusion using argon fluoride lasers. Also, check out how some researchers decided to take lasers to a new frontier in powering “metavehicles” just 10 microns wide.)
References
- Little, B. J., Hoth, G. W., Christensen, J., Walker, C., De Smet, D. J., Biedermann, G. W., Lee, J., & Schwindt, P. D. D. (2021). A passively pumped vacuum package sustaining cold atoms for more than 200 days. AVS Quantum Science, 3(3), 035001. https://doi.org/10.1116/5.0053885
- Sandia National Laboratories. (2021, October 26). This device could usher in GPS-free navigation. https://newsreleases.sandia.gov/quantum_navigation/
- Szondy, D. (2021, November 9). “Titanium avocado” could provide GPS-grade navigation sans satellites. New Atlas. https://newatlas.com/technology/quantum-sensor-vaccum-gps-grade-navigation-no-satellites/
