Yes, run forwards and jump over it, while deflecting it into the ground beneath you for a massive rocketjump. You take almost 50% of your health away including fall damage, although if you don't go up, but more forwards, you take about 50 damage.
It is shocking to see, and theoretically (very rare to happen) the soldier will watch you in awe, try and shoot another rocket at you, and being higher in the air, you can easily deflect back down at his feet. Alternatively, steer yourself in midair to land on top of him and MEL?E for the absolute favourite kill you will ever have! Good luck, I've done it twice in a real game (it really isn't the sort of thing you should be aiming to do), and one of them I just landed closer to the guy with less health than before. So the tactical value is limited. Othertime I got the mel?e kill, which is why fireaxe is better than axtinguisher.