The problem with lasers is that they are unguided, but the advantage is that they move way faster than anything else. Since lasers also move at the fastest communication speed, the will have see you at the same time you see them. The standard response to unguided missiles is to move out of the way, which happens to be very easy in orbit because a small change in veloocity results in a large change in position. Unfortunately, that position is usually on the other side of the orbit, meaning that evading close-quarters fire is fasirly hard. Fortunately, it's very hard to get close enough to a spaceship that lasers would not have prediction problems, and at this range, missiles would both be more effective and (maybe) cheaper. In response to some of the previous posts, missiles could not be kenetic, specifically because of the amount of complexity that would add. The next time you play ksp, I'd like you to destroy a station in orbit around something by positioning it in an orbit going the opposite direction as the station. It's quite hard, because you have to get it to 0m seperation at closest approach, while getting <1 second to make an assesment on where you are. It is an order of complexity greater to do it when the other ship is maneauvering as well. The final blow to this is that the target could simply deploy some chaff. Good luck hitting your target when your missile has been taken out of commision by thousands of micrometeorites. The way space combat is most likely to evolve is to support land combat on a planet or asteroid. An orbiting satellite could be quite effective at delivering large payloads (eg. nukes) and deliver intelligence (already being done). The other half would be ground-launched explosive countermeasures with lots of shrapnel. It is much easier to deal with a target orbiting in the same direction as yourself, and with and explosive warhead, you'd only need to get within the lethal zone (which could be anywhere from 1 km to 10 m). The countermeasures from satellites would probably be ecm in the form of disruptive electromagnetic waves. Anything else would be too heavy for a satellite.