Cinder Lake: Blasting crater fields to test drive Moon cars
Before the first car toured the Moon, Apollo astronauts test drove the lunar rover around dynamite-blasted craters.

In July of 1968, the USGS Branch of Surface Planetary Exploration added a second crater field to their training grounds at Cinder Lake. The endeavor used 1,153 pounds of dynamite, 28,650 pounds of ammonium nitrate fertilizer, and 40,000 feet of detonation cord. Before detonating, one team member, Norman “Red” Bailey apparently rented a “burner” to burn off the plants from the field. The following January, the geologists added extra realism and teaching opportunities for astronauts by “salting” the crater field with additional rocks
The astrogeologists with the U.S. Geological Survey were instrumental in planning the Apollo moonwalks and preparing NASA's astronauts to collect samples and observations while on the lunar surface. Among other noteworthy endeavors, they used explosives to create crater-filled replicas of the Moon’s surface to use in training simulations. To do that, they first tested different amounts of explosives to figure out how to make craters of different sizes, allowing them to closely match the terrain of the Moon
To test logistics long before astronauts arrived for training exercises the geologists would themselves dress up in space suits. Here, astrogeologists Tim Hait and David Schleicher explore their simulated lunar terrain at the Cinder Lake Crater Field in Flagstaff, Arizona, in October 1967. They wanted to see how well astronauts could use different maps and follow planned traverses while navigating an actual crater field. Behind the geologists is a mockup of the lunar module ascent stage.
Another important aspect of the Flagstaff team’s work was to design and demonstrate the hand tools the astronauts would use for sample collection. Here, USGS geologist Tim Hait shows how to take a soil sample from a crater wall in the Cinder Lake Crater Field in March 1968.
The USGS also engineered and tested vehicles for astronaut training. They built this early lunar mission development vehicle, the “Explorer,” in 1967. Here, Dick Wiser takes the Explorer for a spin after the team added a gyrocompass navigation system to the dashboard in July 1968.
The geology of Northern Arizona looks especially Moon-like in this aerial view of Cinder Lake Crater Field 2.
When it came time to build a Moon-bound rover, NASA gave the job to the Boeing Company. But you can’t ride around on a lunar rover on Earth — its Moon-gravity specs would collapse under your Earth-gravity weight. Because of this, Boeing was supposed to provide a “1 G” version of the rover, but as astronaut training approached and USGS was rover-less, they had to get creative. That’s why, the USGS Branch of Astrogeology’s Field Test Support Unit built their own rover replica, mimicking the plans from Boeing, in just 90 days. By August 1970, the new “Grover” — geologic rover — was on its first test drive across Cinder Lake Crater Field. The Grover was used to train crews for Apollo 15, 16 and 17. Here, Apollo 15 astronauts Jim Irwin (left) and Dave Scott participate in a training exercise in November 1970 at the Cinder Lake Crater Field.
Boeing eventually did come up with a “1 G” rover, but it was prone to breaking and couldn’t actually sustain field simulations. NASA spent $1.2 million on it. According to USGS’s Gerry Schaber, “when Don Beattie [the boss] asked Putty [charged with building Grover] how much did this thing cost, Putty said, ‘something like $1,900.’ Beattie said, oh we couldn’t say that to NASA Headquarters — so they multiplied the cost by about 10 and claimed that we built it for $20,000 — still a great bargain.” Here, astronaut Jack Schmitt participates in a final geology exercise with the Grover before Apollo 15 at Coconino Point, Territory of the Navajo Nation, Arizona in June 1971. Schmitt was the only geologist who would also become an astronaut