Cinder Lakes Apollo Training Area
Located in what is now known as the Cinder Hills OHV Area just northeast of Flagstaff are the remnants of the Cinder Lakes Crater Fields (Field #1 and Field #2) that were designed and constructed in July 1967 for astronaut training. Crater Field #1 was specifically designed to duplicate an area within the Mare Tranquillitatis in an effort to train astronauts for the future Apollo mission. Craters range in diameter from 5 to 40 feet and the first phase of the field, which consisted of 47 craters, occurred July 28-31, 1967. The field was expanded in October 8-12, 1967, which added 96 craters (or 143 total). The cinder field is made up of debris that erupted from Sunset Crater in approximately 1064 A.D.
The crater fields were suitable for testing rover prototypes and also used to test procedures for determining location within a cratered lunar landscape. Crews tested their ability to describe crater morphologies and stratigraphic relationships in unconsolidated materials as well as how to use hand tools and test deployment methods for prototype scientific experiment packages. In order to create the crater field, crews excavated holes and filled them with dynamite (312.5 lbs) and ammonium nitrate (13,492 lbs). Test explosions were used to calibrate the amount of explosive needed to generate craters of specific sizes.
Cinder Lake Crater Field #1 was produced in two stages and was 500 x 500 feet. Part of the first stage of the field creation was designed to simulate a small area of the Apollo 11 landing site that was observed in a Lunar Orbiter image. A simulated Lunar Module was installed on a ramp within the crater field for context of where the height of the Apollo ascent windows would be. Astronauts tested mobility systems such as the "Explorer" vehicle and an experimental vehicle called "Grover," which was used to training the Apollo prime and back-up crews.
Cinder Lake Crater Field #2 is located in an area that is used quite frequently by OHV enthusiasts, where basaltic cinders cover clay beds, and thus a light colored clay was excavated by the blasts and produced distinctive markings. Field #2 is 1,200 x 1,200 feet and contains 354 craters, which required 1,153 lbs of dynamite, 28,650 lbs of nitro-Carbo nitrate, and 40,000 ft of Primacord. Several sets of explosions were detonated to create the field and designed to overlap, which simulated lunar impact craters of intermediate age.
Even after all of this time, one can see where the detonations took place if they drive or hike through the area.
For even more photos and information, please visit the city's Flagstaff's Lunar Legacy website. As well, to view a video of how the craters were made, please visit USGS's Astrogeology Science Center website.
Click on the images below for a larger version with explanation of the photo.