NASA's Cold Atom Lab (CAL) was launched into space by a SpaceX rocket in 2018. Since then it has raked up the orbital miles aboard the International Space Station (ISS) while at the same time helping in the study and development of quantum technologies.
The versatile facility, which can be operated remotely from NASA's Jet Propulsion Laboratory on Earth, has recently aided in the creation of "exotic matter" aboard the ISS.
NASA researchers recently reported the production of rubidium Bose-Einstein condensates (BECs) — atoms formed when certain elements are cooled to near absolute zero (0 Kelvin, minus 273.15 Celsius).
Studying BECs in microgravity
BECs share similarities to potassium metal and caesium metal in physical appearance, softness, and conductivity. They are sometimes referred to as the "fifth state of matter" because, in a BEC, matter stops behaving as independent particles and collapses into a single quantum state that can be described with a single uniform wave function.
The problem with BECs is that they are incredibly fragile. As they need to be cooled to such low temperatures, the slightest interaction with the external world is enough to warm them past their condensation threshold.
As such, they are almost impossible to study on Earth. Not only are temperatures too high, Earth's gravity also interferes with the magnetic fields required to hold BECs in place for observation.
"Microgravity allows us to confine atoms with much weaker forces, since we don't have to support them against gravity," Robert Thompson of from the California Institute of Technology, Pasadena, told AFP.
Clearer observations than ever before
The research published in the journal Nature details several stunning differences in the properties of BECs created on Earth with the ones observed aboard the ISS.
BECs in terrestrial labs have typically lasted milliseconds before dissipating. Aboard the ISS, the BECs lasted more than a full second. While this might not seem like much, it allowed the researchers unprecedented insight into the properties of BECs.
Microgravity aboard the ISS also meant that the magnetic fields needed to manipulate the atoms could be weaker, speeding their cooling and allowing for clearer images to be taken.
The research team leader David Aveline said that studying BECs in microgravity opened up a wealth of research opportunities:
"Applications range from tests of general relativity and searches for dark energy and gravitational waves to spacecraft navigation and prospecting for subsurface minerals on the moon and other planetary bodies," he explained.