The abundance of potentially habitable hypersaline environments in our solar system compels us to understand the impacts of high-salt matrices and brine dynamics on biosignature detection efforts. We identified and quantified organic compounds in brines from South Bay Salt Works (SBSW), where evapoconcentration of ocean water enables exploration of the impact of NaCl- and MgCl2-dominated brines on the detection of potential biosignature molecules. In SBSW, organic biosignature abundance and distribution are likely influenced by evapoconcentration, osmolyte accumulation, and preservation effects. Bioluminescence assays show that adenosine triphosphate (ATP) concentrations are higher in NaCl-rich, low water activity (aw) samples (<0.85) from SBSW. This is consistent with the accumulation and preservation of ATP at low aw as described in past laboratory studies. The water-soluble small organic molecule inventory was determined by using microchip capillary electrophoresis paired with high-resolution mass spectrometry (µCE-HRMS). We analyzed the relative distribution of proteinogenic amino acids with a recently developed quantitative method using CE-separation and laser-induced fluorescence (LIF) detection of amino acids in hypersaline brines. Salinity trends for dissolved free amino acids were consistent with amino acid residue abundance determined from the proteome of the microbial community predicted from metagenomic data. This highlights a tangible connection up and down the \"-omics\" ladder across changing geochemical conditions. The detection of water-soluble organic compounds, specifically proteinogenic amino acids at high abundance (>7 mM) in concentrated brines, demonstrates that potential organic biomarkers accumulate at hypersaline sites and suggests the possibility of long-term preservation. The detection of such molecules in high abundance when using diverse analytical tools appropriate for spacecraft suggests that life detection within hypersaline environments, such as evaporates on Mars and the surface or subsurface brines of ocean world Europa, is plausible and argues such environments should be a high priority for future exploration. Key Words: Salts-Analytical chemistry-Amino acids-Biosignatures-Capillary electrophoresis-Preservation. Astrobiology 24, 795-812.

Noise is the primary cause of hearing loss during space flight. Throughout every phase of flight, particularly during launch, a significant amount of noise is generated and transferred via the vehicle\'s structure to the places inhabited by the crew. The results of the previous studies provide insights into space flights that may have significant effects on hearing loss. Certain precautions must be taken to ensure the habitability of the spacecraft and prevent potential hearing loss in astronauts or space flight participants.

Effective transport of biological systems as cargo during space travel is a critical requirement to use synthetic biology and biomanufacturing in outer space. Bioproduction using microbes will drive the extent to which many human needs can be met in environments with limited resources. Vast repositories of biological parts and strains are available to meet this need, but their on-site availability requires effective transport. Here, we explore an approach that allows DNA plasmids, ubiquitous synthetic biology parts, to be safely transported to the International Space Station and back to the Kennedy Space Center without low-temperature or cryogenic stowage. Our approach relied on the cyanobacterium Nostoc punctiforme PC73102, which is naturally tolerant to prolonged desiccation. Desiccated N. punctiforme was able to carry the non-native pSCR119 plasmid as intracellular cargo safely to space and back. Upon return to the laboratory, the extracted plasmid showed no DNA damage or additional mutations and could be used as intended to transform the model synbio host Escherichia coli to bestow kanamycin resistance. This proof-of-concept study provides the foundation for a ruggedized transport host for DNA to environments where there is a need to reduce equipment and infrastructure for biological parts stowage and storage.

Long-duration spaceflight (LDSF) is associated with unique hazards and linked with numerous human health risks including Spaceflight Associated Neuro-ocular Syndrome (SANS). The proposed mechanisms for SANS include microgravity induced cephalad fluid shift and increased Intracranial Pressure (ICP). SANS is a disorder seen only after LDSF and has no direct terrestrial pathologic counterpart as the zero G environment cannot be completely replicated on Earth. Head-down tilt, bed rest studies however have been used as a terrestrial analog and produce the cephalad fluid shift. Some proposed countermeasures for SANS include vasoconstrictive thigh cuffs and lower body negative pressure. Another potential researched countermeasure is the impedance threshold device (ITD) which can reduce ICP. We review the mechanisms of the ITD and its potential use as a countermeasure for SANS.

Lower Body Negative Pressure (LBNP) redistributes blood from the upper body to the lower body. LBNP may prove to be a countermeasure for the multifaceted physiological changes endured by astronauts during spaceflight related to cephalad fluid shift. Over more than five decades, beginning with the era of Skylab, advancements in LBNP technology have expanded our understanding of neurological, ophthalmological, cardiovascular, and musculoskeletal adaptations in space, with particular emphasis on mitigating issues such as bone loss. To date however, no comprehensive review has been conducted that chronicles the evolution of this technology or elucidates the broad-spectrum potential of LBNP in managing the diverse physiological challenges encountered in the microgravity environment. Our study takes a chronological perspective, systematically reviewing the historical development and application of LBNP technology in relation to the various pathophysiological impacts of spaceflight. The primary objective is to illustrate how this technology, as it has evolved, offers an increasingly sophisticated lens through which to interpret the systemic effects of space travel on human physiology. We contend that the insights gained from LBNP studies can significantly aid in formulating targeted and effective countermeasures to ensure the health and safety of astronauts. Ultimately, this paper aspires to promote a more cohesive understanding of the broad applicability of LBNP as a countermeasure against multiple bodily effects of space travel, thereby contributing to a safer and more scientifically informed approach to human space exploration.

Human space exploration expansion from Low-Earth Orbit to deep space is accelerating the need to monitor and address the known health concerns related to deep space radiation. The human musculoskeletal system is vulnerable to these risks (alongside microgravity) and its health reflects the well-being of other body systems. Multiparametric magnetic resonance imaging (MRI) is an important approach for assessing temporal physiological changes in the musculoskeletal system. We propose that ultra-low-field MRI provides an optimal low Size Weight and Power (SwaP) solution for non-invasively monitoring muscle and bone changes on the planned Gateway lunar space station. Our proposed ultra-low-field Gateway MRI meets low SWaP design specifications mandated by limited room in the lunar space station. This review summarizes the current state of our knowledge on musculoskeletal consequences of spaceflight, especially with respect to radiation, and then elaborates how MRI can be used to monitor the deleterious effects of space travel and the efficacy of putative countermeasures. We argue that an ultra-low-field MRI in cis-lunar space on the Gateway can provide valuable research and medical insights into the effects of deep space radiation exposure on astronauts. Such an MRI would also allow the development of imaging protocols that would facilitate Earth-bound teams to monitor space personnel musculoskeletal changes during future interplanetary spaceflight. It will especially have a role in monitoring countermeasures, such as the use of melanin, in protecting space explorers.

Lunar exploration offers an exciting opportunity for humanity to advance scientific knowledge and future potential economic growth and possibly allow humans to become a multi-planetary species. On April 2, 2024 the US Office of Science and Technology Policy released a memorandum outlining the current Biden-Harris Administration\'s policy on the need to establish time standards at celestial bodies other than Earth. This memorandum also introduced the need for Coordinated Lunar Time (CLT), the concept of having a reference time for the moon. The establishment of CLT would provide a multitude of benefits for astronaut health, from expedition planning, to maintaining a sense of order in an austere environment. International agreements and collaboration will be required prior to the recognition of CLT.

Gravity has had a significant impact on the evolution of life on Earth with organisms developing necessary biological adaptations over billions of years to counter this ever-existing force. There has been an exponential increase in experiments using real and simulated gravity environments in the recent years. Although an understanding followed by discovery of counter measures to negate diminished gravity in space had been the driving force of research initially, there has since been a phenomenal leap wherein a force unearthly as microgravity is beginning to show promising potential. The current review summarizes pathophysiological changes that occur in multiple aspects of the cardiovascular system when exposed to an altered gravity environment leading to cardiovascular deconditioning and orthostatic intolerance. Gravity influences not just the complex multicellular systems but even the survival of organisms at the molecular level by intervening fundamental cellular processes, directly affecting those linked to actin and microtubule organization via mechano-transduction pathways. The reach of gravity ranges from cytoskeletal rearrangement that regulates cell adhesion and migration to intracellular dynamics that dictate cell fate commitment and differentiation. An understanding that microgravity itself is not present on Earth propels the scope of simulated gravity conditions to be a unique and useful environment that could be explored for enhancing the potential of stem cells for a wide range of applications as has been highlighted here.

As spaceflight becomes increasingly accessible and expansive to humanity, it is becoming ever more essential to consider the treatment of various eye diseases in these challenging environments. This paper delves into the increasing fascination with interplanetary travel and its implications for health management in varying environments. It specifically discusses the pharmacological management of ocular diseases, focusing on two key delivery methods: topical eye drops and intravitreal injections. The paper explores how microgravity impacts the administration of these treatments, a vital aspect in understanding drug delivery in space. An extensive analysis is presented on the pharmacokinetics of eye medications, examining the interaction between pharmaceuticals and ocular tissues in zero gravity. The goal of the paper is to bridge the understanding of fluid dynamics, microgravity and the human physiological systems to pave the way for innovative solutions faced by individuals in microgravity.

The long-term cultivation of higher plants in space plays a substantial role in investigating the effects of microgravity on plant growth and development, acquiring valuable insights for developing a self-sustaining space life supporting system. The completion of the Chinese Space Station (CSS) provides us with a new permanent space experimental platform for long-term plant research in space. Biological Culture Module (GBCM), which was installed in the Wentian experimental Module of the CSS, was constructed with the objective of growing Arabidopsis thaliana and rice plants a full life cycle in space. The techniques of LED light control, gas regulation and water recovery have been developed for GBCM in which dry seeds of Arabidopsis and rice were set in root module of four culture chambers (CCs) and launched with Wentian module on July 24, 2022. These seeds were watered and germinated from July 28 and grew new seeds until November 26 within a duration of 120 days. To this end, both Arabidopsis and rice plants completed a full life cycle in microgravity on the CSS. As we know, this is the first space experiment achieving rice complete life cycle from seed-to-seed in space. This result demonstrates the possibility to cultivate the important food crop rice throughout its entire life cycle under the spaceflight environment and the technologies of GBCM have effectively supported the success of long-term plant culture experiments in space. These results can serve as invaluable references for constructing more expansive and intricate space plant cultivation systems in the future.