Station Science Top News: Feb. 9, 2024
Top tier result
Researchers found similar changes in gene expression in plants from two separate investigations. Many previous plant studies used identical hardware on Earth as controls, but it is difficult to adequately replicate on the ground the stresses that plants may face in spaceflight. This research uncovered unique, microgravity-specific changes in gene expression, highlighting the validity and importance of an onboard 1 g control. Understanding the molecular mechanisms of adaptation to microgravity could help researchers determine optimal conditions for growing plants in space.
Understanding how plants adapt to space is essential to their use on future long-duration missions. Plant growth is highly responsive to light and gravity. Plant Signaling, conducted in cooperation with the ESA (European Space Agency), studied the effects of various gravity levels on the growth responses of plant seedlings. Plant RNA Regulation compared gene expression involved in development of roots and shoots in microgravity and simulated 1 g. The European Modular Cultivation System used by these investigations has a centrifuge that makes it possible to create a 1 g control in space and to examine the effects of partial gravity.
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Top tier result
Researchers found that three types of microorganisms previously identified in space dust survived the harsh conditions of space for at least two years. One hypothesis is that the organisms essentially freeze dry, or partially freeze and dehydrate, in space. Widely used to preserve microbial strains for storage, freeze drying increases the viability of spores and reproductive cells. These findings contribute to understanding of whether and how life may propagate through space.
Scientists discovered “space dust” on the outer surface of station modules, and Roscosmos conducted the investigation Test to determine its properties and detect any biological structures and viable microorganisms. Analysis identified bacteria, fungi, and archaea DNA and viable strains of bacteria. The researchers also report specific effects of space exposure on each, including slowed growth in archaea and increased resistance to radiation in fungi.
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Staphylococcus aureus, a highly infectious bacterium, increases secretion of factors in spaceflight cultures, which may make it a more virulent pathogen. This altered metabolism indicates the need for close monitoring of S. aureus during flight to prevent infectious disease outbreaks that could affect mission success.
Spaceflight is known to weaken the immune system and to increase the strength of some pathogens. BRIC-23 studied how Bacillus subtilis spores and Staphylococcus aureus cells respond to space. A better understanding of how microbes adapt to spaceflight, including whether their adaptations change antibiotic effectiveness, supports efforts to maintain crew member health.
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Researchers used 2D images to train artificial intelligence to create 3D structures that they used to examine the microstructural characteristics of cement samples solidified in microgravity. Analysis indicated that the 3D microstructures captured the microstructural differences between space and ground samples. These results enhance the understanding of cement microstructure, advancing its potential use for habitats and other structures on the Moon and Mars.
Transporting raw materials into space is costly, so extraterrestrial construction may need to use on-site materials with cement-like binders. MICS investigated the process of cement solidification in microgravity and evaluated the properties of mixtures of different types and amounts of cement, additives, and water. This paper presents a unique way to determine the microstructure of cement samples hydrated on the space station.
