In a study published on August 13th, 2024, in Nature Communications, scientists used one of the lab's onboard instruments to measure the space station's faint vibrations. This is the first time that ultra-cold atoms have been used to detect environmental changes in space.
NASA’s Cold Atom Lab, shown where it’s installed aboard the International Space Station, recently demonstrated an atom interferometer that can precisely measure gravity and other forces — and has many potential applications in space. Image Credit: NASA/JPL-Caltech
NASA’s Cold Atom Lab, an innovative laboratory located on the International Space Station, has made significant progress in transforming the use of quantum research in space exploration.
The study also presents the longest evidence of the wave-like behavior of atoms in freefall in space.
The Cold Atom Lab scientific team conducted their observations using an atom interferometer, a quantum instrument that can detect gravity, magnetic fields, and other forces precisely.
This technology is used by scientists and engineers on Earth to explore the underlying physics of gravity and enhance systems for aircraft and ship navigation. (Cell phones, transistors, and GPS are a few other key inventions based on quantum science that do not need atom interferometry.)
Physicists have been keen to employ atom interferometry in space because microgravity allows for longer measurement intervals and higher instrument sensitivity, but the highly delicate equipment has been deemed too frail to operate for lengthy periods without hands-on help. The Cold Atom Lab, which operates remotely from Earth, has demonstrated this is conceivable.
Reaching this milestone was incredibly challenging, and our success was not always a given. It took dedication and a sense of adventure by the team to make this happen.
Jason Williams, Project Scientist, Jet Propulsion Laboratory, NASA
Power of Precision
Space-based sensors that can detect gravity with great precision have several potential uses. For example, they might reveal the makeup of planets and moons in our solar system because various materials have varying densities, resulting in minor differences in gravity.
This type of measurement is already being carried out by the US-German partnership GRACE-FO (Gravity Recovery and Climate Experiment Follow-on), which detects small changes in gravity to track the flow of water and ice on Earth. An atom interferometer might improve accuracy and stability while exposing more information about surface mass changes.
Accurate gravity measurements could shed light on the properties of dark energy and dark matter, two significant cosmic riddles. Compared to the “regular” matter that makes up planets, stars, and everything else that is visible to us, dark matter is an unseen component that is five times more prevalent in the universe. The unidentified force responsible for the universe’s rapid expansion is known as dark energy.
Atom interferometry could also be used to test Einstein’s theory of general relativity in new ways. This is the basic theory explaining the large-scale structure of our universe, and we know that there are aspects of the theory that we don’t understand correctly. This technology may help us fill in those gaps and give us a more complete picture of the reality we inhabit.
Cass Sackett, Study Co-Author and Professor, University of Virginia
A Portable Lab
The Cold Atom Lab, roughly the size of a minifridge, was sent to the space station in 2018 with the intention of improving quantum science by establishing a permanent laboratory in the low-Earth orbit microgravity environment. In the lab, atoms are cooled to minus 459 degrees Fahrenheit or minus 273 degrees Celsius, which is virtually absolute zero.
A Bose-Einstein condensate, a state of matter where all atoms effectively share the same quantum identity, can develop by certain atoms at this temperature. As a result, some of the atoms’ previously tiny quantum qualities become macroscopic, making them simpler to examine.
Examples of quantum qualities are acting like waves or solid objects at different moments. Although scientists are unsure how these fundamental components of all matter can switch between disparate physical properties, they are searching for solutions utilizing quantum technologies, such as that found in the Cold Atom Lab.
Bose-Einstein condensates can stay longer and at lower temperatures in microgravity, providing scientists with additional possibilities to investigate them. The facility has many technologies, like the atom interferometer, that allow for precise observations, using the quantum nature of atoms.
Because of its wave-like nature, a single atom can concurrently traverse two physically distinct pathways. By tracking how the waves interact and recombine, scientists can determine if gravity or other factors are influencing those waves.
I expect that space-based atom interferometry will lead to exciting new discoveries and fantastic quantum technologies impacting everyday life, and will transport us into a quantum future.
Nick Bigelow, Study Co-Author and Professor, University of Rochester
More About the Mission
Cold Atom Lab, supported by the Biological and Physical Sciences (BPS) division of NASA's Science Mission Directorate at the agency’s Washington headquarters, was planned and constructed by JPL, a part of Caltech located in Pasadena. BPS facilitates scientific exploration and advances scientific discovery by employing space settings to carry out research that is not feasible on Earth.
By studying biological and physical processes under harsh conditions, researchers could enhance life on Earth and expand the basic scientific understanding needed to travel farther and survive in space.
Journal Reference:
Williams, J. R., et. al. (2024) Pathfinder experiments with atom interferometry in the Cold Atom Lab onboard the International Space Station. Nature Communications. doi.org/10.1038/s41467-024-50585-6