sentences:  Approximately 40 minutes after separation, when the spacecraft was at a safe distance, the impactor was fired into the asteroid surface by the detonation of shaped charge of plasticized HMX for acceleration.The copper impactor was shot to the surface from an altitude of about 500 meters and it excavated a crater of about 10 meters in diameter, exposing pristine material.The next step was the deployment on 4 June of a reflective target marker in the area near the crater to assist with navigation and descent.