Spinner

Transferring fluids between space vehicles is a necessity when conducting in-orbit servicing, assembly, and manufacturing (ISAM). Fluid resources such as propellant, coolant, and water are going to be critical for space logistics. However, transferring fluids in microgravity presents a unique problem. Typically, on terrestrial systems we utilize a pump system and place the pump inlet in the source fluid’s lowest gravity point which ensures we’ll recover nearly all the source fluid. However, in microgravity we are not able to leverage these gravitational density driven modes of fluid management. NASA has successfully tested and leveraged fluid and propellant transfers in-orbit, however most of these systems leverage pressure fed systems with baffled tank designs [1]. Most fluid transfers and characterization has been done at the small scale and with most research focused on capillary fluid transfer and handling [2,3].  There have been some proposals leveraging centrifugal applications for fluid handling, however, these proposals were focused on phase/flow separations or using pressure fed systems. [4,5].
Other microgravity tests have taken place testing pump fed systems transferring fluids back and forth between two separate containers. However, due to gas-ingestion these systems experience a ~30% yield [6].

SPINNER is a microgravity fluid transfer experiment which leverages centrifugal forces and nested containers, to transfer fluids between containers and concentrate their volume in a single location. By leveraging centrifugal forces from the source container, we can possibly eliminate the need for pressure fed systems and increase volumetric efficiency. This can also reduce system cost and complexity for future ISAM fluid transfer systems. Future work will explore integrating pump fed systems with SPINNER to effectively transfer fluids from one spacecraft to another.

[1]       Abdalla, K. L., Otto, E. W., Symons, E. P., and Petrash, D. A. Liquid Transfer Demonstration on Board Apollo 14 During Transearth Coast. 1971.
[2]       Gluck, D. F., and Gille, J. P. “Fluid Mechanics of Zero G Propellant Transfer in Spacecraft Propulsion Systems.” SAE Technical Papers, 1964. https://doi.org/10.4271/640220.
[3]       David F. Chao, Robert D. Green, Tyler Hatch, John B. McQuillen, William V. Meyer, Henry Nahra, Padetha Tin, and Brian J. Motil. A Researcher’s Guide to: Fluid Physics. NASA ISS Program Office, 2015.
[4]       Singh, B. S., and J. Iwan D. Alexander. Microgravity Fluid Physics and Transport Phenomena Experiments Planned Aboard the International Space Station. No. 504, 2003, pp. 232–239.
[5]       Kawanami, O., Imai, R., Azuma, H., Ohta, H., Honda, I., and Kawashima, Y. “A Microgravity Experiment of the On-Orbit Fluid Transfer Technique Using Swirl Flow.” Annals of the New York Academy of Sciences, Vol. 1077, No. 1, 2006, pp. 288–303. https://doi.org/10.1196/ANNALS.1362.016.
[6]       Erkel, D. Ouroboros - Microgravity Fluid Transfer Suborbital Flight Test Demonstration (Draft Pending Release). Cambridge, MA, 2022.