While the Ranger spacecraft sent NASA the first images of the Moon, NASA scientists needed higher resolution photos of the entire Moon - not just the places where the Ranger satellites had crashed! To do so, they designed the Lunar Orbiter satellites.
Photo Credit: NASM
Photo Credit: NASA
The first Lunar Orbiter was launched August 10th, 1966 and took pictures of the Moon between August 18th and 29th. The final Lunar Orbiter was launched and imaged the Moon in August 1967. When each orbiter completed its mission, it was crashed into the Moon in order to keep their radio signals from interfering with future spacecraft.
The Lunar Orbiter program's mission was to map the Moon's surface before the Apollo missions. All five launches were successful, and the satellites took pictures of 99% of the Moon's surface, including both the nearside and the farside of the moon.
While the Ranger satellites were the first satellites to take pictures of the Moon, the Lunar Orbiters were the first satellites to take pictures from lunar orbit and the first to take pictures of the Earth from the Moon! Through these pictures, NASA was able to build a more detailed understanding of the Moon's surface and its hazards, like deep craters.
The Lunar Orbiters used high resolution cameras to take photos to create the very first maps of the lunar surface, and helped NASA pick a landing site for the Apollo missions. These satellites picked up important details about the Moon's terrain.
These images show us the craters and the rocky terrain of the Moon. Unlike on Earth, there is no water and no wind on the Moon, so the surface of the Moon doesn't weather or erode the same way as the Earth's surface does. How do you think the processes of weathering, erosion, and deposition might happen in an environment that is very different from the Earth's?
This video, created by NASA in the late 1960s, describes the Lunar Orbiter's mission and how it converts and sends the photographs it took back to Earth.