In the 50 years since the Apollo missions took man to the moon there are a lot of images and sounds that have become a part of our history. There’s "Houston, Tranquility Base here. The Eagle has landed." And of course "That's one small step for man, one giant leap for mankind." But do you remember an astronaut on the surface of the Moon saying "This is a rock and rolling ride!"
That's what astronauts Dave Scott and Jim Irwin said as they took the first lunar rover out for a shakedown. Officially called the Lunar Roving Vehicle, it was a part of the final three Apollo missions and dramatically changed those moon missions.
"The fact is that the rover changed everything,” said Earl Swift, an author, and journalist whose new book chronicles the story of the moon mobiles. It’s called “Across the Airless Wilds: The Lunar Rover and the Triumph of the Final Moon Landings."
“We sent six missions up (to the moon, seven if you count Apollo 13 which never landed on the Moon)" said Swift. "The first three, the astronauts were on foot (and) the final three they drove the rover. And there’s no comparison. (During) Apollo 11, Neil Armstrong, and Buzz Aldrin walked an area that was smaller than a football field; you could fit all of their wanderings into a football field with a lot of yardage left over. On the last mission, on Apollo 17, Gene Cernan and Jack Schmitt drove more than 22 miles, and at one point they were very close to five miles away from their lunar module.”
Lunar rovers have existed in science fiction since the beginning of the 20th Century. Then, in the early 1950s, almost a decade before President John Kennedy issued his “end of the decade moon challenge”, former German SS Officer turned American rocket scientist Wernher von Braun wrote an article for Colliers Magazine describing land vehicles that could operate on the lunar surface.
“Enormous, hulking Caterpillar-tractor style rovers with pressurized tanks that could travel for 500 miles. And then you see private industry start nosing around on the idea in the very late 50s. It moved into high gear in the early to mid-1960s, with companies like G.M., Boeing, Grumman, Bendix all studying concepts on how to best move astronauts around. It was obvious from early on that after the first few (moon) flights, the astronauts were going to need to drive if they were going to fulfill all of the potential of the missions to the moon.”
It also became obvious that the vehicle would have to be much smaller than the original concept. Anything that large would require a second Saturn 5 rocket to deliver it to the moon. So they needed a compact design that could be carried on the existing lunar module. But in the late 60s, NASA’s budget was cut and they abandoned the idea of having a rover during the Apollo missions. That didn’t stop engineers in private companies from continuing their research.
“And a Hungarian refugee named Ferenc Pavlics, Frank to his American friends, came up, after four months of trial and error, with a folding rover. A tiny, aluminum go-cart that could fold like a business letter and fit inside the one cargo bay that was available on the lander. It weighed next to nothing, it was minimalist, but it was a pretty viable idea. So Pavlics made a one-sixth scale model of it, and he and his boss Sam Romano took it to Huntsville, (Alabama) to the Marshall Space Flight Center where (Wernher) von Braun was the director. They showed it to him and legend has it that he slammed his fist down on his desk and said ‘Ve must do this!’ and the rest is history.”
Building a vehicle on Earth that could navigate on the Moon had many challenges. At the time no one was 100% sure exactly what the lunar surface was made of and how tracks or wheels would gain purchase. There was also the lack of gravity and the extreme temperatures.
“We’re talking temperature extreme that range from 250 degrees below zero to 250 above Fahrenheit. An airless, hard vacuum, a constant bombardment of cosmic radiation and micro-meteorites which might be the size of a grain of sand but they’re moving faster than bullets and they can do some damage.”
And then there’s the lack of clouds or buildings or telephone poles for that matter, ways we usually use to judge distance and find your way back after a drive. Since the Moon has no magnetic field a compass would be useless.
“They did devise this pretty ingenious system that measured where you were in relation to a starting point. So at the beginning of each drive, Mission Control in Houston and the astronauts on the Moon would agree as to where they were on the Moon’s surface. And as the astronauts drove, inside their control console were electronics that basically married a directional gyro, which just keeps track of where the nose of the rover was pointed, and odometers in each of the wheels. And by keeping track of where you are headed and how far you go in that direction, the astronauts always knew where they were, where they were headed, where the lunar module was in relation to where they were, and what was the fastest route back to the lunar module if they ran into trouble.”
Swift says that NASA has been working on better models of the rover ever since the Apollo missions, and the agency has never given up on returning to the Moon. The next lunar mission is scheduled to land on the lunar South Pole in 2023. The crew will be an unmanned lunar rover called the Viper.
