Hazal A. Kara
Introduction to the ISS
The International Space Station (ISS) is a large spacecraft that orbits the Earth at 90-minute intervals [1]. Many countries are involved in the ISS collaboration: the USA, Canada, Japan, Russia, and member states of the European Space Agency. The first piece of the ISS was launched in 1998, and by November 2000, the ISS was ready for its first crew. Although, collaborators continued assembling the space station until the spacecraft was completed in 2011.
On the ISS, astronauts can conduct scientific research that cannot be replicated on Earth. For example, the recent Crew Dragon Demo-2 mission astronauts will participate in scientific experiments on the space station. In this article, we will examine the different types of research conducted on the ISS.
Biological and Agricultural Sciences
Plant Biology
Using the ISS as their laboratory, researchers can understand how a microgravity environment affects plant growth and metabolism [2]. This has allowed astronauts to grow edible plants, which they are able to consume rather than eating freeze-dried food. However, it is important to ensure the nutritional composition of these plants match those grown on Earth.

Proteins and Large Molecules
All proteins have a unique three-dimensional structure made up of amino acids that determines their function. Crystallization – specifically neutron crystallography – is utilized in determining protein structure. Neutron crystallography provides great structural detail but requires large protein crystals that cannot be easily obtained on Earth. In the ISS’s microgravity environment, large crystals are formed and allow scientists to get a better look at protein structure. By studying the protein structure of these large crystals, researchers are able to develop better drugs
Human Body
“The Human Research Program” (HRP) is a NASA program that focuses on understanding the impacts of space travel on the human body in order to make long-distance space travel safer in the future [4]. This research encompasses exercise physiology, behavioral health, the effects of space radiation, and more.

In order for a Mars mission to take place, scientists must study gravity fields, the psychological impact of isolation for long periods of time, and space radiation [5]. For instance, NASA has learned that transitioning from one gravity field to another can change a human’s spatial orientation, head-eye and hand-eye coordination, balance, and locomotion.
Microbiology
As bacteria are living organisms, space-flight affects them as well. However, these effects remain unknown [6]. Researchers on the ISS are trying to find the answers to questions such as: “What underlying genetic, molecular and biochemical processes are influenced by the spaceflight environment?” and “Does long-duration spaceflight alter normal rates of evolutionary change?” [6]
Physical Sciences
Fluid Dynamics
Microgravity causes fluids to move drastically different in space than on Earth. By understanding fluid dynamics, specifically inertial spreading (defined as “the movement of liquid across a solid surface in such a way that liquid inertia and surface tension are the dominant competitors” [7]), in microgravity, researchers can apply their findings to the manufacturing, agricultural, and medical industries. For example, interior spreading is involved in immersion lithography, which is used for producing semiconductor chips for faster computer processors.

Combustion
In the microgravity environment of the ISS, flames take on a spherical shape [8]. Similar to fluids and proteins, this shape allows researchers to conduct experiments with the flames that cannot be done on Earth. The main objective of these experiments is to discover ways to improve fuel efficiency and reduce pollutant production.
Remote Sensing
With the help of the ISS, new remote sensing technologies can help natural disaster response, land and sea monitoring, environmental science, and space imaging [9]. For example, space imaging on the ISS will allow particle physicists and planetary scientists to measure phenomena including X-ray sources, cosmic rays, as well as the Sun’s radiation. It may also assist with the search for dark matter.
Bibliography
[1] Hitt, David. 2018. \”What Is The International Space Station?\”. NASA. https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-the-iss-58.html.
[2] \”Plant Biology Overview\”. 2018. NASA. https://www.nasa.gov/spacebio/plant.
[3] Williamson Smith, Amelia. 2019. \”Designing Better Drugs: Piecing Together Protein Function Through Structure\”. Issnationallab.Org. https://www.issnationallab.org/blog/designing-better-drugs-piecing-together-protein-function-through-structure/.
[4] \”About HRP\”. 2019. NASA. https://www.nasa.gov/hrp/about.
[5] Abadie, Laurie J., Charles W. Lloyd, and Mark J. Shelhamer. 2020. \”The Human Body In Space\”. NASA. https://www.nasa.gov/hrp/bodyinspace.
[6] \”Microbiology Overview\”. 2018. NASA. https://www.nasa.gov/spacebio/microbiology.
[7] Williamson Smith, Amelia. 2019. \”Looking At Liquid Motion In Microgravity\”. Issnationallab.Org. https://www.issnationallab.org/blog/looking-at-liquid-motion-in-microgravity/.
[8] Winick, Erin. 2020. \”Cleaner Combustion On Earth, Safer Combustion In Space\”. NASA. https://www.nasa.gov/mission_pages/station/research/news/combustion-research-microgravity-clean-burning-fuel-space-station.
[9] \”Earth Science And Remote Sensing Onboard The ISS National Lab\”. 2020. Issnationallab.Org. Accessed June 7. https://www.issnationallab.org/research-on-the-iss/areas-of-research/remote-sensing/.
Figure References
Fig 1: \”Growing Plants In Space\”. 2020. NASA. https://www.nasa.gov/content/growing-plants-in-space.
Fig 2: Wilson, Beth. 2017. \”Staying In Shape In Space\”. NASA. https://airandspace.si.edu/stories/editorial/staying-shape-space.
Fig. 3: Williamson Smith, Amelia. 2019. \”Looking At Liquid Motion In Microgravity\”. Issnationallab.Org. https://www.issnationallab.org/blog/looking-at-liquid-motion-in-microgravity/.