Annual Highlights of Results 2023: Measuring the Impact and Evolution of Space Station Research

The International Space Station (ISS) has been the largest and most technologically advanced laboratory in low Earth orbit for the past 25 years. This collaborative effort between various space agencies, including NASA, ASI, CSA, ESA, JAXA, and Roscosmos, has seen thousands of researchers from around the world conducting investigations, analyzing data, and publishing their findings. In this article, we will explore the significant impact and evolution of space station research, as detailed in the Annual Highlights of Results 2023 report.

Measuring Space Station Impacts
The impact of sustained international multidisciplinary research in microgravity can be observed through the groundbreaking findings published in world-class scientific journals that undergo rigorous scientific peer-review processes. With the assistance of Clarivate, a global database that collects publication and journal information for annual journal ranking and metrics, we identified the top findings produced by station researchers. One parameter, the journal’s Eigenfactor Score, ranks each journal based on readership and influence, including the different citation standards of each discipline.

From October 1, 2022, to September 30, 2023, 78 articles appeared in top-tier journals. Of those 78 articles, 26 were reported in the top 20 journals. These articles covered a wide range of topics, including plant root orientation, tissue damage and repair, bubbles, lightning, fire dynamics, neutron stars, cosmic ray nuclei, imaging technology improvements, brain and vascular health, solar panel materials, grain flow, and satellite and robot control.

Moreover, a comparison of station science to global and US standards of category-normalized citation impact shows greater influence of station science since 2010 compared to other research endeavors taking place domestically or internationally. This increased authority of station research was particularly prominent in 2019 and continues to hold its place in the scientific community to date.

Evolution of Space Station Results
The current decade of research results has seen significant improvements in processes and software tools to enhance communication with research teams for better in-flight data collection and sample return. These refinements have affected experiment results and the conclusions researchers draw. Enhanced planning and coordination of investigation launch, stowage, crew time allocation, accessibility to station’s research capabilities, and data delivery are critical to the effective operation of scientific projects for accurate results to be shared with the scientific community, sponsors, legislators, and the public.

Since Expedition 1, over 3,700 investigations have operated on the ISS, with more than 250 active research facilities, the participation of over 100 countries, the work of over 5,000 researchers, and over 4,000 publications. The growth in research and international collaboration has prompted the publication of over 560 research articles in top-tier scientific journals, with about 75 percent of those groundbreaking studies occurring since 2018.

Linking Space Station Benefits
Bibliometric analyses conducted through VOSviewer measure the impact of space station research by quantifying and visualizing networks of journals, citations, subject areas, and collaboration between authors, countries, or organizations. Using bibliometrics, a broad range of challenges in research management and research evaluation can be addressed. The network visualizations, stacked charts, and line graphs provided in this report demonstrate the growth and influence of station research.

Figure 1: Bibliometric mapping of station research growth over time. Count of the keyword microgravity co-occurring at least five times with other research keywords at different time periods. A) 1999-2005: n=11; B) 2006-2011: n=49; C) 2012-2017 n=69; D) 2018-Sep. 2023: n=115. The node size represents the number of publications containing the research keywords (larger nodes = more publications), the distance between nodes represents relatedness between research keywords, and the colors represent different research areas.

Figure 2: Bibliometric mapping of station collaboration growth over time. Measurement of co-authorship strength (i.e., total line thicknesses) between the United States and other countries in the network at different time periods. A) 1999-2005: total link strength = 19; B) 2006-2011: total link strength = 74; C) 2012-2017: total link strength = 150; D) 2018-Sep. 2023: total link strength = 442. Nodes represent the number of publications for each country. Distance and color are not relevant indicators in this chart.

Figure 3: Count of publications reported in journals ranked in the top 100 according to global standards of Clarivate. A total of 567 top-tier publications through the end of FY-23 are shown by year and research category.

In this year’s edition of the Annual Highlights of Results, we report findings from a wide range of topics in biology and biotechnology, physics, human research, Earth and space science, and technology development. These investigations include studies about plant root orientation, tissue damage and repair, bubbles, lightning, fire dynamics, neutron stars, cosmic ray nuclei, imaging technology improvements, brain and vascular health, solar panel materials, grain flow, as well as satellite and robot control.

Many more studies in fiscal year (FY)-23 revealed remarkable results, such as finding reduced fat accumulation in the bone marrow (MARROW), identifying gene mutations that preserve muscle (Molecular Muscle), improving optical beams…detecting bacterial antibiotic resistance during spaceflight (Plazmida), observing abnormal cell division of human neural stem cells (STaARS Bioscience-4), among others.

A publicly accessible database of space station investigations and publications can be found in the Space Station Research Explorer (SSRE) website, and all editions of the Annual Highlights of Results from the International Space Station can be found through the Past Annual Highlights of Results from the Space Station Research Results Library.

Publications by Agency and Research Category
Between October 1, 2022, and September 30, 2023, we identified a total of 330 articles associated with station research. Of these 330 articles, 268 appeared in peer-reviewed journals, 59 in conference proceedings, and 3 in gray literature such as books, magazines, technical reports, or patents. Articles were also categorized based on how authors obtained their results. There were 204 publications that reported direct implementation of the science aboard station (i.e., Results), 37 that reported development of the payload prior to operation on station (i.e., Flight Preparation), and 89 that emerged as follow-ups to station science (i.e., Derived).

Figure 4: Count of publications by agency and station research category. A total of 330 articles were collected in FY-23.

Figure 4 shows a stacked chart with the count of articles collected in FY-23 broken out by space agency and research category. In summary, we found three articles for CSA, 43 articles for ESA, 58 articles for JAXA, 10 articles for Roscosmos, and 216 articles for NASA. Of the 330 articles collected in FY-23, 66 were articles published prior to October 1, 2022.

In conclusion, the International Space Station has been a significant contributor to scientific research and discovery for the past 25 years. The findings published in top-tier scientific journals demonstrate the impact and influence of station research, which continues to grow and evolve with the collaboration of international partners and the dedication of researchers from various disciplines. The advancements in technology and research on station have inspired students to pursue STEM careers, encouraged researchers to explore bold questions, and incentivized economies through the initiation of businesses in the space industry. The future of space station research holds great promise for the advancement of science and technology.