Goals: This last of the Ranger series of missions was to provide live TV images of the Moon's Alphonsus crater and the surrounding area en route to crashing into the crater.

Accomplishments: Ranger 9 impacted the lunar surface just 6.5 km off target, well within Alphonsus crater. During its descent at nearly 3 km per second, it transmitted pictures with resolution down to 25 cm, viewed live by TV audiences. Tracking data from the Ranger missions was used to improve knowledge of the Moon's mass by an order of magnitude and to determine that the Moon's center of mass is displaced from its geometric center.