Your are driving the red fighter. Remember that the red arrow marks your speed? If you don't, you should look at the first tutorial on movement. Now there's also a missile. It is marked by the orange triangles: the bigger one marks its current position, the smaller one indicates where it will go to if it doesn't use thrust... but be sure: it will! First of all the missile must lock on some target. Here, the brown hexes mark the missile's line of sight. It is a 120 wide arc, and reaches as far as the asteroids, which block the missile's line of sight. As you can see from the crosshair, the missile has chosen your (red) fighter! It has chosen you because the line of sight is traced from the initial hex (where the missile is at the beginning of the turn, the bigger triangle) and not from the smaller triangle, and the missile locks on to the fighters' initial positions. Your fighter (the red one) is at distance 2, while the blue one is at distance 4: this why the missile locks on you. The crosshair appears on your final position, however, because that is where the missile will try to hit you. You click on the fighter's image, and then hit LKKK on your keyboard to escape from the missile. This is the result: The crosshair is following you! This is because missiles move after the fighters, and know where fighters are going.
You will arrive at a distance of 7 hexes from the missile's speed (the orange triangle). A missile has a thrust of 7, and will need to turn at least a couple of times, so you should be safe! You hit "SUBMIT" in the form at the beginning of the screen... ... and this is the result: The missile is three hexes away from you! This is good: it has built up speed in the meanwhile (the dashed arrow) and will probably go against the asteroids on the next round. But how did this happen exactly? You press T on your keyboard to toggle the view and see what happenend during the previous round:

The missile's dashed arrow indicates its speed, the solid arrow marks its real movement. The missile knew where you were going, and was trying to catch your final position: remember that missiles move after the fighters!
Its move was LLSSRSS. Not a really smart move: it could probably have gotten a bit nearer to you (it zig-zagged too much).
As you can see, the blue fighter didn't move: was this a good choice? Suppose it tried to catch you:

The missile would have tried to make exactly the same move, trying yo catch you: the orange arrow which marks its desired movement didn't change. However, since the final position of the blue fighter is now right on its path, it explodes on the blue fighter instead!