Station Science Top News: Jan. 12, 2023
On Jan. 11, 2023, the SpaceX CRS-26 Dragon capsule splashed down off the coast of Florida, carrying science hardware and samples from the International Space Station. Some of the scientific investigations that Dragon carried home included:
- Astrorad, a vest designed to protect astronauts from high doses of radiation caused by unpredictable solar-particle events. The vest’s developers plan to use astronaut feedback from months of testing to improve design of the garment, which could provide radiation protection for astronauts on Artemis missions to the Moon.
- The eXposed Root On-Orbit Test System, or XROOTS, which used hydroponic (water-based) and aeroponic (air-based) techniques to grow plants without soil or other traditional growth media. Similar techniques could be used to produce crops for future space missions and to enhance cultivation and food security for the benefit of people on Earth.
- Bioprospecting is the process of identifying plants and animals that may contain substances with potential for use as drugs, biochemicals, and more. Previous studies found that space can cause changes that could result in microbes yielding such materials. Rhodium Microgravity Bioprospecting-1 studied a way to search for these microbes. The science chambers and temperature logger from the investigation returned to Earth for further examination.
Red and green tomatoes grow in an XROOTS growth chamber. Researchers tested hydroponic and aeroponic methods as alternatives to traditional growth media for producing plants in space. Credits: NASA
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NASA’s Global Ecosystem Dynamics Investigation (GEDI) instrument aboard the space station collected 2.5 years of baseline data from tropical and temperate regions of the world. Researchers estimate there is about 29% more biomass in the 169 observed countries than approximated by the Food and Agriculture Organization. These models set a baseline for Earth science data. Future measurements can give clues as to how our planet is changing.
GEDI was designed to observe changes in carbon stored in Earth’s forests, landforms, and atmospheric carbon dioxide concentrations to monitor climate change. Statistical considerations involving proper sampling and error modeling allowed researchers to calculate precise estimates and produce accurate maps. While GEDI’s statistical models may still benefit from some corrections, researchers remain confident in the potential of this tool for Earth monitoring.
Here, the GEDI investigation is located on the Japanese Experiment Module-Exposed Facility aboard the International Space Station. Credits: NASA
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NASA’s Cold Atom Lab (CAL) simultaneously produced Bose-Einstein Condensates (BECs) of two atomic species (rubidium and potassium) for the first time in space. Potassium atoms provide researchers the opportunity to change the interactions between the atoms at will. This opens new opportunities ranging from fundamental studies of few-body physics — a particularly thorny subfield of physics involving the behavior of three or more interacting particles — to demonstrations of quantum device concepts.
When clouds of atoms reach these ultracold temperatures, they may form a fifth state of matter called a Bose-Einstein Condensate (BEC). BECs make the quantum properties of atoms macroscopic so that scientists can more easily observe them. An in-orbit repair and replacement of a critical microwave frequency driver by NASA astronaut Megan McArthur in 2021 enabled the effort to produce two species of BEC. This allowed potassium to be produced at ultracold temperatures in CAL.
The Cold Atom Lab in operation aboard the Destiny module in the International Space Station. Credits: NASA
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ESA’s (European Space Agency’s) Multiscale Boiling study found that during boiling, bubbles under the influence of an electric field begin to separate from a flat surface before the force from electric stress starts to pull them away. This was contrary to expectation. Increased understanding of bubble behavior could improve heat exchange technology and produce safer, small-scale-powered devices for space travel.
Researchers filmed the process of boiling perfluorohexane, a highly flammable chemical often used as a heat-transfer fluid or refrigerant, using high-speed cameras. Scientists also found that during the separation process, the point where the bubble meets the surface (known as the contact line) shrank at a faster rate, which was consistent with theoretical predictions. Last, results showed that increasing voltage impedes bubble growth due to an increase in internal pressure caused by electric stress throughout the bubble and, particularly, at the apex. All these results provide information that can be applied to design of future space heat exchangers.
ESA astronaut Luca Parmitano installs the MultiScale Boiling experiment container in the Columbus Module aboard the space station. Credits: NASA