RESULTS
Five soldering sessions resulted in 86 samples. The experiment samples were returned to the
investigator team in late 2005 and were evaluated both nondestructively and then
destructively. A number of both expected and unexpected observations were made. Real-time
downlink video of the experiment yielded direct observation of the solder melting, equilibrium
shape attainment by the liquid, and flux movement. The flux movement was particularly
noteworthy because it was entirely unexpected. When the flux was released from the solder
during heating, it formed a droplet that spun around the larger solder drop. This surprising
movement is driven by thermocapillary flow induced by the temperature gradient and cannot
be duplicated on Earth. Researchers developed a model derived from both space-based
observations and ground-based
experiments to provide insight into
the observed flux spinning (Grugel
2006, 2008).
PUBLICATION(S)
Grugel RN, Luz P, Smith G, et al.
Materials research conducted aboard
the International Space Station:
Facilities overview, operational
procedures, and experimental
outcomes. Acta Astronautica. 62
(2008):491–498.
doi:10.1016/j.actaastro.2008.01.013.Grugel RN, Cotton LJ, Segre PN, et al. The In-Space Soldering Investigation (ISSI): Melting and
solidification experiments aboard the International Space Station. 44th Aerospace Sciences
Meeting and Exhibit. Reno, NV; 2006.
Grugel RN, Luz P, Smith GA, et al. Experiments conducted aboard the International Space
Station: The Pore Formation and Mobility Investigation (PFMI) and the In-Space Soldering
Investigation (ISSI): A current summary of results. Proceedings of the 57th International
Astronautical Congress (IAC), Valencia, Spain; October 2-6, 2006.
This investigation is complete; however additional results are pending publication.
Expedition 9 Science Officer Mike Fincke works on In Space
Soldering Investigation in the US Laboratory, Destiny.