Experimental analysis of laser ablated plumes for asteroid deflection and exploitation

It has been theoretically demonstrated that laser ablation is effective in the potential deflection and mitigation of asteroids. However, there have been few experimental studies to support this claim. The theoretical models are currently based on assumptions regarding the laser beam diameter, the power requirement, the formation of the ejecta plume, and the potential for ejecta to contaminate and otherwise degrade any exposed surface. Recent proposals suggesting the use of a solar pumped laser, in particular, can be deeply affected by the re-condensation of the ejecta. To either validate, amend and/or eliminate these assumptions a series of laser ablation experiments have been performed. Using a 90 W, continuous-wave laser operating at 808 nm, a rocky magnesium iron silica based material – olivine – has been ablated. These experiments were used to examine the validity of the theoretical model and the experienced levels of contamination. It will be shown that the current model correctly predicts the ablated mass flow rate for rocky based asteroids, but overestimates the contamination rate and the degradation of the optics.

► Compared to the model, reduced ejecta degradation effects were observed.
► Comparable mass flow rate between the experiment and the theoretical model.
► The experiment resulted in a higher gas velocity and estimated thrust.
► Over time, the experiment's plume formation experienced a lower divergence angle.