An earlier post described the European Space Agency’s Asteroid Impact Mission (AIM), which in 2020 will send a probe to the Didymos binary asteroid system. AIM will initially “perform high-resolution visual, thermal and radar mapping of the moon”, i.e. the smaller of the two asteroids, “to build detailed maps of its surface and interior structure”.
Two years later, NASA’s DART (Double Asteroid Redirection Test) spacecraft will reach Didymos and collide into the moon while observed by AIM. The goal is to measure the amount of deflection of the asteroid and record the effects of the collision on the surface structure of the asteroid. This joint mission is called the Asteroid Impact & Deflection Assessment (AIDA) study.
Here is a video about the AIM plan: