Dexterous manipulation of molten metals in microgravity remains unsolved

Establish a practical and reliable method for dexterous manipulation of molten metals in microgravity, specifically enabling accurate steering of molten samples from an induction furnace to a casting process while preventing damage to surrounding components and loss of material during transfer.

Background

The paper motivates a four-stage in-orbit recycling process for space debris, emphasizing step (iii): carrying and positioning molten aluminum droplets using time-varying magnetic fields that induce eddy currents. This step is critical because controlling molten metals in microgravity must be both precise and non-contact to avoid contamination and equipment damage.

While electromagnetic levitators and related technologies have demonstrated heating and static positioning of conductive samples, dynamic dexterous manipulation of molten metals in microgravity has not been solved. The authors present closed-loop position control of semi-buoyant aluminum spheres in a lab as a preliminary step toward addressing this gap, highlighting the broader open challenge of manipulating molten metals during transfer from furnace to casting in microgravity.

References

This steering from the furnace to cast (step (iii) in Figure \ref{fig:recyclingProcess}) is a critical step in the process, as dexterous-manipulation of molten metals in the absence of gravity is yet an unsolved problem, and could represent a step in the process where components are at risk of being damaged by molten metals.

— Non-Contact Manipulation of Induced Magnetic Dipoles  (2511.02761 - Stewart et al., 4 Nov 2025) in Section 1 (Introduction), paragraph following Figure 1 (Recycling Process)