Station Science Top News: Aug. 11, 2023

by ISS Program Science Office | 2023-08-15

Researchers examined the sloshing of liquid inside a tank in microgravity and found that a passive liquid helped stabilize the system when the tank is moved. These results could provide insight into strategies for safely steering spacecraft containing liquid fuels.

In space, liquid fuels can slosh in unpredictable ways and create disturbances and imbalances that affect spacecraft maneuvers. The SPHERES Tether Slosh investigation used the station’s SPHERES robots to test strategies for steering fluid-filled containers. The results have applications in scenarios such as using a spacecraft to tow a satellite for deorbiting, where the spacecraft may contain a significant quantity of liquid fuel. Potential applications on Earth include controlling sloshing of fuel in airplane wing tanks.

An astronaut floats with metallic cubes on the space station. — European Space Agency astronaut Alexander Gerst is photographed during a Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) Tether Slosh experiment test session run. **Credit: NASA**/**Serena Auñón-Chancellor**

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Scientists measured properties of liquid zirconium (Zr) using NASA’s ground-based Electrostatic Levitation (ESL) facility and JAXA’s in-orbit Electrostatic Levitation Facility (ELF). They report a new method to compare the performance of each facility based on the precision and accuracy of such measurements. This comparison helps researchers determine which facility is most effective based on the class of materials studied and other factors.

To produce glass, metal alloys, and other materials, raw materials are heated in a container called a crucible. But chemical reactions between the materials and the crucible can cause imperfections and contamination. Levitation eliminates the need for a container, reducing these imperfections and facilitating studies of material behavior. The ELF provides superior measurements thanks to microgravity, but its samples are less stable and sample movement creates uncertainties in temperature measurements. The ESL offers ease of access and equipment that yields lower uncertainties.

Two astronauts work to fix equipment on the space station. — Commander Peggy Whitson and flight engineer Jack Fischer are photographed during operations to remove a Ground Cable from the Electrostatic Levitation Furnace (ELF). **Credit: NASA/Thomas Pesquet**

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Researchers evaluated the performance of the Quetzal-1 CubeSat’s electric power system, which was designed in-house. Results showed that the system’s solar chargers generated enough power for operations without overcharging a storage battery and an onboard heater prevented the battery from freezing during maximum eclipse. Developing more efficient ways to power satellites with less hardware is increasingly important for future satellite designs.

Quetzal-1 was launched by JAXA for Universidad del Valle de Guatemala (UVG) and completed imagery operations from April to November of 2020. The satellite’s electric power system had to generate enough power using photovoltaic cells and store enough power on a rechargeable battery to allow continuity of operations in eclipse. The authors make specific recommendations to improve the power system design based on their evaluation.

Read more here.

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The 12th annual International Space Station Research and Development Conference (ISSRDC), sponsored by the ISS National Lab, brought together more than 900 leaders in academia, industry, and government to discuss the space station’s role in future research and development.

The event was held in Seattle July 31 to August 3, 2023. Speakers included NASA Chief Scientist and Senior Climate Advisor Katherine Calvin, NASA astronaut Megan McArthur, and representatives from space station international and commercial partners.