I’m ploughing my way through Walter Lewin’s 8.01 Physics course online. He recently covered orbital mechanics, on which today’s invention is based.
It’s a way to sample the surface of an asteroid without having to create and deploy a costly lander.
A body in space with no atmosphere, such as an asteroid, would allow a small spacecraft (yellow) to enter into orbit around it (1->2->3->4->5).
From this would be ejected backwards a tiny (red) satellite (eg a cubesat).
This could be given an intial speed just great enough to allow it to return to the mothership, without significant additional fuel cost or active control, following the kind of orbit shown.
As the cubesat passed close to the asteroid’s surface, it would drop a small mass which would create a plume of dust through which the craft could fly on a second orbit before returning to the main satellite.
I’m tempted to suggest that repeated applications of this technique could be used to erode and thus deflect a dangerous, earthbound rock.