https://phys.org/news/2018-07-image-binary-asteroids.html

"ESA's Hera mission, currently under study, would be humankind's first mission to a binary asteroid system, targeting the Didymos pair of Near-Earth asteroids," explains Paolo Martino, Hera system engineer.

"The plan is to map surface features of these bodies on an automated basis to pinpoint Hera's position in space and chart its onward trajectory. And GRALS is letting us test candidate navigation algorithms in a real-world way."