Can this be doable in theory? Because who in the right mind would build this :) Let us imagine if we could build a steel rod, that has mass of 1 Kg, that has length about 300000 km. Yeah I know, impossible, but how about some material that can weight 1Kg or even 10Kg. But in space even 1000 tons of material is like a feather. Now let's say that we anchor one side to earth, asteroid or whatever. If rod is r in circle, then quarter of circle would be 471000 km. Now few cm from anchor we push or pull rod for a 1/4 circle, because there is no resistance in space/universe, or it is minor, it could be pushed or pulled by a second or fraction of a second. So the far end would cross 471000 km by a second or less.