Agnirva Space Premier League - Expedition #30889: How Liquids Move in Space: Investigating Wicking in Gel-Coated Tubes

In our everyday lives, we rarely think about how liquids move inside tubes. But in space, where gravity doesn’t dictate flow, understanding fluid behavior becomes incredibly complex—and important. That’s the focus of the experiment "Wicking in Gel-Coated Tubes," led by Dr. Émilie Dressaire from the University of California, Santa Barbara, and supported by BioServe Space Technologies.

Conducted over Expeditions 70, 71, and 72 on the International Space Station (ISS), this experiment falls under the Physical Science category and is sponsored by NASA. Its goal? To study how liquids travel through narrow, gel-coated tubes in a microgravity environment—a process known as capillary action or wicking.

Wicking is vital for a host of space applications: from transporting coolant in thermal systems to moving fuel in engines or even getting water to plant roots in hydroponic systems. In space, where gravity can’t pull fluids downward, understanding how to guide them through capillary forces becomes key.

The use of gel-coated surfaces in this study adds another layer of complexity. These coatings mimic biological or industrial conditions where surface texture and chemistry can significantly affect how fluids behave. By experimenting with different gel types and tube geometries, scientists can fine-tune systems for more reliable and efficient fluid management in space habitats.

Findings from this study will not only improve the design of spacecraft systems but may also have applications back on Earth—in medical devices, inkjet printers, and microfluidic chips used in diagnostics.

This experiment exemplifies how small-scale phenomena can have large-scale implications, especially when performed in the unique environment of the ISS.

Get certified with over 100 hours of immersive, self-paced learning in astronomy, cosmology, space technology, and climate science through the Agnirva Space Internship Program. Join, complete virtual projects, and earn a digital certificate to showcase your space fluency in interviews, resumes, and beyond.