3 ms·And is also a way to send a signal back...by jacobush 7y agoAnd is also a way to send a signal back...olooney 7y agoGood point!pugworthy 7y agoIn this case (Breakthrough Starshot), the core of the probe weighs grams. It would never make it to the ground.jacobush 7y agoI was more thinking about the flash when something of relativistic speed hits something else. An atmosphere for instance.