After a year of orbital study, the probe was at the end of its operational lifespan, and controllers decided it might as well go out with a bang. Of science! They used the last of the propellant to start a slow dive toward the surface, to take as many pictures as possible on the way down and to teach these Near Earth asteroids that they're not the only ones in the solar system that can go around slamming into things. As an orbiter, NEAR Shoemaker had less landing gear than a fish and was even less likely to survive. They'd only slowed it down so they'd know exactly when to high five and aim middle fingers at the sky.
This is for the dinosaurs, asshole!
So when NEAR Shoemaker sent signals asking "OK, I'm down, what's next?" they had to think of something very quickly, to make sure the unkillable spacebot didn't work out that they'd just tried to murder it. NASA begged extra time from the Deep Space Network communications array, otherwise the probe would have come back to find out why they stopped returning its calls. A gamma ray spectrometer designed to work at a range of kilometers was reprogrammed for the slightly more in-your-face 10 centimeters. NEAR Shoemaker continued to send unprecedented data for another 16 days, and spent the whole time wondering when they'd let it deploy the drills and nuclear warheads.
It worked so well that NASA designed another probe to ram a comet on purpose. And just to take the piss out of movies that weren't as cool as what they do, they called it Deep Impact.