The Space Omics and Medical Atlas (SOMA) and international astronaut biobank

Human space exploration is rapidly expanding, yet the biomedical challenges for astronauts in extreme environments remain significant. Prolonged spaceflight causes various health issues, including bone and muscle loss, cardiovascular problems, and immune dysfunction. Understanding the underlying mechanisms requires comprehensive biomolecular characterization, which has been limited by small cohort sizes. Previous studies like the NASA Twins Study and the JAXA CFE project, while insightful, lacked the statistical power needed for comprehensive analysis. This study leverages data from various missions, including the SpaceX Inspiration4 mission, to create a more extensive molecular atlas of spaceflight's effects on the human body.

Existing research highlights the detrimental effects of spaceflight on astronaut health. Studies like the NASA Twins Study provided valuable insights into the molecular and cognitive changes in a single astronaut during prolonged spaceflight. The JAXA Cell-Free Epigenome (CFE) project analyzed cell-free DNA and RNA from a small group of astronauts. These studies, along with others focusing on specific physiological changes (bone density loss, immune dysfunction, etc.), laid the groundwork for a more comprehensive understanding of the problem but were limited by sample size and the scope of omics data available. The need for larger, integrated datasets was clearly identified in the literature to achieve sufficient statistical power and a more nuanced perspective on astronaut health.

The Space Omics and Medical Atlas (SOMA) integrates data from multiple space missions, including the NASA Twins Study, JAXA CFE study, SpaceX Inspiration4, Axion, and Polaris missions. SOMA includes a wide range of omics data: genomics, epigenomics, transcriptomics (including single-cell and spatial transcriptomics), proteomics, metabolomics, and microbiome data. The data are linked to the Cornell Aerospace Medicine Biobank (CAMB), which stores biospecimens for future analysis. The study uses various analytical techniques to identify differentially expressed genes (DEGs), differentially methylated genes, and changes in chromatin accessibility. The analysis includes a comparison of the SOMA dataset with the NASA Open Science Data Repository (OSRD), representing a substantial increase in publicly accessible human space omics data. The data were analyzed across three timeframes: flight, recovery, and longitudinal profiles to examine immediate, short-term, and long-term effects of spaceflight. Specific analyses included PBMC snRNA-seq, whole blood dRNA-seq, skin spatially resolved transcriptomics, cfDNA, and microbiome profiling. Statistical methods such as mixed-effects linear models were used for analysis and the coefficient of variation was calculated to assess individual variations in responses to spaceflight.

SOMA comprises nearly 3,000 samples and over 75 billion sequenced nucleic acids, representing a substantial increase in available data. Consistent findings across missions include cytokine shifts, telomere elongation, and gene expression changes related to immune activation, DNA damage response, and oxidative stress. The study compared findings with those from the NASA Twins Study, showing overlaps in telomere changes and cytokine responses, despite differences in mission duration. Single-cell RNA sequencing revealed cell-type-specific responses to spaceflight, with T cells and monocytes showing the most significant changes. Analysis of cell-free RNA (cfRNA) provided a body-wide view of tissue stress and cell responses. Microbiome analysis showed variability across body sites and individuals. Pathway enrichment analysis highlighted the involvement of various pathways, including Toll-like receptor signaling, TNF signaling, and T cell receptor signaling pathways. The study also identified significant individual variations in responses to spaceflight across different omics data types. The data was organized into different browsers to facilitate access and use by the scientific community. A significant finding was the rapid telomere elongation observed in astronauts even during shorter missions, which contradicts previous findings that this phenomena only emerged during long-duration space travel.

SOMA provides a comprehensive resource for studying the effects of spaceflight on human health. The findings demonstrate that short-duration spaceflight induces widespread molecular changes, some mirroring those observed during longer missions. The dynamic recovery profiles suggest the activation of restorative mechanisms post-flight, which can be used for therapeutical target discovery. The single-cell data highlighted cell-type-specific responses, while cfRNA profiling offered a body-wide perspective. The observed individual variations underscore the need for personalized approaches to astronaut health monitoring. The comprehensive nature of the data allows for comparison across different missions and cell types, enabling a more holistic understanding of spaceflight’s impact on the human body. The multi-omics approach gives a very detailed picture of the stress response of the body to space travel. These data highlight the need for further research into long-term effects and personalized interventions.

SOMA represents a groundbreaking resource for advancing space medicine. The integrated multi-omic data, coupled with biospecimens, enable large-scale analysis and accelerate the development of personalized countermeasures. Future research using SOMA can focus on understanding long-term effects, identifying novel biomarkers, and developing targeted interventions. The open access nature of the data encourages collaborative efforts to address the unique challenges of space exploration.

While SOMA represents a significant advance, several limitations exist. Variations in assay protocols and collection methods across different missions may introduce some inconsistencies in data comparison. The relatively small sample size limits the generalizability of some findings. Further, the focus on a high-altitude, short-duration mission may limit direct applicability to all types of space missions. Additionally, the study only considered a limited range of omics data types.