The Lunar Roving Vehicle, or LRV, allowed astronauts to travel farther from their lunar modules and carry more equipment with ease despite wearing bulky space suits. Furthermore, its design made using it even simpler.
Its aluminum chassis was hinged to fit neatly into a bay on the lunar module, and production took only 17 months from General Motors and Boeing to broaden Apollo surface mission capabilities.
The design
The lunar module (LM) provided only limited space for its equipment and supplies to fit, forcing the rover to fit within this tight confines. When fully packed, it was more than six feet long and almost five feet wide, roughly equivalent to a small van. Made of 2219 aluminum tubing welded assemblies featuring foldable front and rear sections which folded over onto one another when stored, held together by pin retract mechanisms, telescoping tubes, push-off rods and other gadgets.
Mobility was an integral component, comprising wheels, traction drive, suspension and steering systems. The astronaut seated in the crew station used a T-shaped hand controller on the control and display console post to operate this system and maneuver forward/backward/left/right the vehicle as desired.
Driving over Moon dusty surfaces caused its wheels to push down onto it and create a plume of regolith as they passed by, sending waves of fine regolith upwind with each pass, which was kicked up into astronaut’s space suits, leading to overheating issues and leading them to overheat more rapidly than expected. To mitigate this effect, engineers developed dust guards for each wheel.
The LRV also contained several additional systems beyond its mobility systems, including: crew station with two seats and control/display console between them; television camera for remote communications with Mission Control; science payloads such as tools, samples and instrument stowage bags. Furthermore, an onboard dead reckoning navigation system displayed its location as well as distance to LM.
The lunar rover was intended to operate for several hours during each lunar day and could make exploration sorties as far as 92 kilometers (57 miles). This limit was determined based on how much oxygen and coolant was available in astronauts’ portable life support systems should all systems fail on its mission.
The engineering
One of the greatest challenges of earlier Apollo missions was traversing the moon’s dusty regolith terrain. Although astronauts could spend considerable time outside their lunar module (LM), their mobility was often constrained by limited energy supplies, spacesuit durability and oxygen availability – an issue which became less of a factor with the advent of the rover.
Marshall Space Flight Center’s Rover Team set out to create an all-terrain vehicle capable of withstanding lunar environments while carrying everything needed by astronauts for EVAs. Furthermore, engineers had to ensure their weight wasn’t excessive; while still remaining tough enough for lunar terrain but not adding unnecessary bulkiness.
General Motors provided them with invaluable assistance by designing the wheel system and creating a prototype that fit easily inside LM. Engineers then used this rover as a test bed for the LRV itself – engineers utilized its ability to drive across uneven lunar surface terrain while handling any bumpiness; weight tests with and without payloads attached were conducted as well as how much the vehicle could support on EVAs.
Apollo 15, 16 and 17 astronauts found such great success with their LRV that they used it all over the moon to predetermine locations for geological samples and other work, climbing out each time to perform assignments before driving back to replenish their air and water supply at LM. Thanks to this vehicle, they covered four times more ground than on previous Apollo missions.
The rover was carefully designed to operate smoothly on the moon; however, like any machine it can experience setbacks. One such issue was discovered quickly on their first trip out when steering issues surfaced quickly due to damage sustained from launch accident; with quick fixes applied by astronauts they completed all three planned excursions of their LM successfully.
The testing
The rover had to be small enough to fit inside the lunar module’s storage bay while still remaining sturdy enough to travel over rugged terrain at up to six miles per hour, traversing slopes up to 25 degrees with ease. Furthermore, it must withstand extreme temperature swings–due to lack of atmosphere on the Moon–and operate effectively at one sixth of Earth’s gravity; otherwise astronauts might struggle with staying balanced while standing on it.
Engineers at Boeing employed Space Chamber A to test their rover, simulating conditions on the Moon’s surface as accurately as possible. Pumps removed air to create a vacuum while giant refrigerator coils filled with liquid nitrogen chilled it to -320 degrees; high intensity xenon arc lamps produced sunlight glare; while liquid-nitrogen filled tubes acted like giant refrigerator coils chilled the chamber further down to -320. Engineers further tested it by driving it over obstacles simulating lunar terrain such as rocks and craters at speeds reaching 30 feet per second – astronauts would have no time for recovery should something arise whilst on Moon!
After passing its initial test drive, the rover was loaded with the weight it was designed to carry on the Moon, dropped in a lunar simulation to ensure it would fold up and fit back into its storage bay after landing, and driven for another 78 hours while simulating sorties on the lunar surface before dropping it back again to simulate an impact with lunar surfaces.
The rover was an essential tool during Apollo missions 15 through 17. It enabled crews of Apollo 15, 16, and 17 to quickly arrive at their destinations, gather geological samples or conduct other scientific activities without needing to walk too much; and it reduced most of their need to walk–which could be slow, tiring and dangerous. Unfortunately however, several unexpected problems did arise: for instance when Commander Gene Cernan accidentally broke off one of its fenders when setting his pocket hammer against it–preventing dust from being kicked up into astronaut faces or equipment- luckily NASA created a map-and-duct tape replacement fender so no harm came befall them!
The landing
Apollo 15’s crew arrived safely on the Moon on August 7th 1971 after 12 days and seven hours in space, exploring with a rover for the first time, venturing farther than any astronaut had on previous missions. Commander David Scott and Lunar Module Pilot James Irwin successfully conducted their exploration.
Clad in heavy spacesuits, the astronauts stepped from their LM and into their LRV. Now in control, they were ready to begin exploring the Moon.
The rover featured a front compartment equipped with communications equipment (high-gain antennas for voice and data communications, low-gain antennas for TV/VCR pictures), power (two 36-volt batteries) and navigation systems; behind this was its two-seat lawn-chair-type body equipped with aluminum chassis wheels with galvanized piano wire mesh treads and titanium chevron treads – these being fitted into its aluminum chassis and galvanized piano wire mesh wheels, along with galvanized piano wire mesh tread wheels; while its rear compartment held scientific and rock sampling gear.
At landing, astronauts used mylar tape to slowly lower the rover onto the Moon’s surface and activate support cables and telescoping tubes that provided it with enough support for safe landing away from the LM. Release pins, spring-loaded legs, and various mechanisms also helped unfold and secure its landing location.
Once on the Moon, the rover was powered by electric motors that drove each wheel independently. A navigation system kept track of overall direction and distance traveled from LM with a combination of directional gyro, odometer, and Sun-shadow devices.
The Apollo 15 mission covered nearly 13 km (9 miles) during each EVA traverse, or drive by astronauts over the course of its three EVA traverses. To view where they went visit this temporal traverse map which displays astronaut activities minute-by-minute (sometimes second by second) along with Dr. Phil Stooke’s meticulous mapping and digitalized path of LRV’s path based on meticulous mapping done prior to launch; you can even switch over to stereo view to follow its progress!