Something to consider: going as fast as we are, if we flew right into the outer layers of the sun, we might emerge again from the sun before there was time for us to heat and burn up. That would create a very considerable deceleration. Indeed, as a calculation quickly shows, too much deceleration. We would perhaps survive; our humans, not. So the more complicated solution of gravitational drag must be studied. Would however have been interesting to fly right through a star and out the other side!