NASA Technical Publication: Can you weld on Mars?

[Frank S]

Does this technology have some kind of tracking ability, to follow the filler wire and bead? I didn't see any method of the operator knowing where the laser was going to be applying the heat, yet the welds, and subsequent smoothing of imperfections (jealous!!) in some of them, were awesome!

Note the operator sitting and viewing the weld area through and optic viewer his left hand is on the dial like that of a milling machine