Shooting a rocket at something in space is very obvious, akin to shooting someone in a crowd with a canon. Everybody that is not deaf and blind (sensor arrays or radar of some type in this case) is going to notice.<p>Changing the orbit of another satellite is very noticeable too. Much like if you were in the desert and a car came over the horizon straight at you, you&#x27;d have a very long time to do something about it.<p>A heat beam is a little more concerning. It is a threat that presents itself in seconds, not minutes or days. If it happens at a point where you don&#x27;t have your own IR optics watching space you could miss it and be very confused as to what occurred to your sat.