The concept of space travel was so new to us that when President Kennedy published his famous lunar speech, not even NASA’s leading scientists were completely sure they could actually land on the lunar surface. Some thought that any boat that settled here would simply sink into the moonlight like a massive, airless pit of moving sand! In his latest book, Through Airless Greetings: The Lunar Rover and the Triumph of the Final Lunar Landings, journalist and former Fulbright colleague, Earl Swift, examines the Apollo 15, 16 and 17 missions often overlooked, our last trips to the surface of the Moon (at least until the Artemis project is done). In the excerpt below, Swift takes the reader on a tour of JPL’s hyper-rigorous lunar test track and the battle for the supremacy of the rovers brought here between GM and Bendix.
From the book BETWEEN AIRLESS SAVIORS: The Lunar Rover and the Triumph of the Final Lunar Landings by Earl Swift. Copyright © 2021 by Earl Swift. From Custom House, a line of books by William Morrow / HarperCollins Publishers. Reprinted with permission.
Throughout 1962 and 1963, both GM and Bendix kept an eye on the Surveyor program. However, in the summer, the Jet Propulsion Laboratory presented its requirements for a 100-pound remote-controlled rover that it wanted to put on board the landers. The vehicle will explore the terrain for up to a mile from the Surveyors, while its drivers back on Earth have guided it with television eyes. The lab has warned companies that they plan to submit an offer for the Phase 1 design study – the first normal stage of any new hardware program – that it plans to provide engineering models of its concepts. Proposals were to come in seven weeks.
The short deadline has shocked amateurs. In October the two departing companies – GM and Bendix – began working under contract. GM was ready with its six-wheel design. His lunar Surveyor vehicle was six feet long on eighteen-inch wheels and weighed ninety pounds – half the size and half as heavy as its test bench, with one sure foot that was no less drop-proof. . On Pavlics’ “moonlight” of rocks, craters and slopes outside the Santa Barbara lab, he climbed forty-five-degree slopes, jumped twenty-inch cracks, and bent down in fury and over thirty-inch stairs.
Bekker and Pavlics have been working on the idea for more than three years since then. His main advancement this time around: the rollers. Again, they were made of thread, but were knotted into a wide mesh that resembled chain, and formed into fat donuts. Like the wire tires before the team, they emptied when they hit an obstacle and absorbed some of the shock of cross-country trips. They worked with or without a fabric cover.
“We had a big program going to try to come up with the wire material that would survive the vacuum environment on the moon,” John Calandro recalled. “Frank had designed a test device that created the aspiration environment we needed.”
When fully prepared for a mission, the rover would be an electronic marvel, with subsystems supplied by RCA Astro-Electronics and AC Electronics, a GM division in Milwaukee: it would have a stereo TV imaging device, sophisticated navigation and control, and silver batteries. -zinc recharged from the solar panel. But Santa Barbara’s part of the work, the vehicle itself, was a study to do more with less. The hardware was constantly “being evaluated to see if anything simpler might be able to do the same job,” designer Norman J. James will recall. “‘The part that stops is never broken’ was an often repeated phrase.”
Bendix took a radically different approach. His SLRV was a squared, two-part, articulated robot, with curved legs, shock-absorbing at its corners that ended up in small assemblages of caterpillar tracks. The tracks run independently to follow uneven terrain. His managers guided him with commands to slow down, accelerate or reverse the tracks on one side or the other, and the pivot linking the two halves did the rest. At the moon, it would be powered by a radioisotopic thermal generator – a small nuclear device – hanging from the spine, and set up with scientific instruments and antennas. He weighed a hundred pounds.
Side by side with the GM model, the Bendix machine looked bulky and clumsy, and those small tracks didn’t seem so much a match for Pavlics ’almost spherical wire rolls. But Bendix made a realistic plan until May 1964 when a panel from the U.S. Geological Survey, Caltech, and NASA brought the two models into a volcanic field north of Flagstaff, Arizona, and the he walked away on the injured Bonito. Lava flow. “We had a little section where they could really get into some pretty raw stuff,” Jack McCauley of the Geological Survey recalled years later. “The GM vehicle was perfect. He went from point A to point B without any mishap or turning.
“Poor Bendix’s vehicle had tanklike feet that were made of some sort of rubber-type thing,” McCauley said. “The vehicle began to break down.” In fact, when they finished halfway through, there were no more steps left. So, the GM thing has obviously been our blessing. ”
General Motors had marked a decisive victory. Unfortunately, he didn’t get attached to a rover on the moon. The “Rover Boys,” as that panel of testers became known, were very impressed with the six-wheel drive, but their capabilities did not match the requirements of the Jet Propulsion Laboratory: namely, “turn around and take pictures every ten meters, and also to use a penetrometer to see what the strength of the lunar terrain was — and to do it in a preordered way, ”McCauley said. “Basically, it’s enough to do a network survey.” Bendix had produced too few rovers for the mission; GM had produced too much. The Rover Boys have stated melancholy that no rover meets the stated needs of the Surveyor program, and that was one of the reasons why NASA thwarted the rover component shortly thereafter.
By that time, JPL’s Ranger program had finally given NASA its first careful look at the moon. By conception, they were flimsy flares: Ranger probes flashed on the lunar surface while taking high-resolution photos until the moment of impact. Conceived in 1959, the program had, at times, seemed like another exercise in frustration. After Rangers 1 and 2 made two development test trips in 1961, Rangers 3 to 6 arrived, which were busted. It wasn’t until July 1964, and Ranger 7, that the program began to pay for land. When the spacecraft crashed into the moon, its cameras dropped, and, for about seventeen minutes, it took and transmitted photographs of the approaching surface – 4,316 images in all, some of them at a resolution hundreds of times. larger than the best taken from Earth. The photos did not allay the fears inspired by the writings and lectures of Thomas Gold, but they did establish that the maria was smooth enough for a landing.
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