The Double Asteroid Redirection Test probe, known as DART, is programmed to head toward a tiny rock millions of miles from Earth and then collide with it.
NASA wants to demonstrate that DART can nudge an asteroid, in this case the moonlet known as Dimorphos, off course.
That makes DART something of a test run for a potentially planet-saving maneuver.Over the next year, the probe will power up its ion thrusters and slowly gain speed as it makes its way toward the asteroid pair.
It's a relatively inexpensive metal box with two rollout, extendible solar arrays for power, a single camera and a smaller satellite, or CubeSat, that'll be deployed right before impact.
The teeny satellite will deploy 10 days before DART's asteroid impact, providing essential footage of the collision and subsequent plume of materials.
NASA hopes to catch the collision's juicy details before, during and after impact, so "in its final moments," the Johns Hopkins University overview says, "DART's DRACO camera will help characterize the impact site by providing high-resolution, scientific images of the surface of Dimorphos."