NASA's Newest Concept Vehicles Take Off-Roading Out of This World
Images above: While designing the lunar truck, JSC engineers threw out some traditional assumptions on what a vehicle needs -- for instance, doors and seats -- and added interesting new capabilities such as active suspension, six-wheel drive with independent steering for each wheel. Credit: NASA
In a car commercial, it would sound odd: active suspension, six-wheel drive with independent steering for each wheel, no doors, no windows, no seats and the only color it comes in is gold.
But NASA's latest concept vehicle is meant to go way, way off-road -- as in 240,000 miles from the nearest pavement, driving on the moon. NASA is working to send astronauts to the moon by 2020 to set up a lunar outpost, where they will do scientific research and prepare for journeys to destinations like Mars.
NASA is testing many technologies needed for research on the moon. Two examples are a lunar truck for astronauts and a rover equipped with a drill designed to dig into the moon's soil.
View images of the lunar truck.
View video of the lunar truck. Windows Media
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The concept for a future lunar truck was built at NASA's Johnson Space Center, Houston. The vehicle provides an idea of what the transportation possibilities may be when astronauts start exploring the moon. Other than a few basic requirements, the primary instruction given to the designers was to throw away assumptions made on NASA's previous rovers and come up with new ideas.
"To be honest with you, it was scary when we started," said Lucien Junkin, a Johnson robotics engineer and the design lead for the prototype rover. "They tasked us last October to build the next generation rover and challenge the conventional wisdom. The idea is that, in the future, NASA can put this side-by-side with alternate designs and start to pick their features."
One of the first standards to go was the traditional expectation that a vehicle should have four wheels. Mars rovers Spirit and Opportunity, still cruising around the Red Planet, have already proved the value of a couple of extra wheels. When one of the six wheels became inoperable, the rovers had no problem rolling on the remaining five.
With the number of wheels decided, the next question was just how those wheels should turn. On a car, the front wheels turn a few inches in either direction, and both wheels point in the same direction. On this rover, all six wheels can pivot individually in any direction, regardless of where any other wheel points. To parallel park, a driver could pull up next to the parking place, turn all the wheels to the right and slide right in.
Of course, astronauts will not have trouble finding a parking space on the moon. But the feature, called crab steering, has advantages for a vehicle designed to drive into the craters of the moon. If a slope is too steep to drive down safely, the vehicle could drive sideways instead -- no backing up or three-point turns required. The all-wheels, all-ways steering also could come in handy when unloading and docking payloads or plugging into a habitat for recharging.
Introducing crab steering drove the concept in a few other ways. If the rover's wheels turn to drive in a different direction, the driver needs to be able to do the same. The driver stands at the steering mechanism because sitting in a spacesuit is not comfortable or practical. The astronaut's perch -- steering mechanism, driver and all -- can pivot 360 degrees.
"The Apollo astronauts couldn't back up at all because they couldn't see where they were going in reverse," said Rob Ambrose, assistant chief of the Automation, Robotics and Simulation Division at Johnson. "If you have a payload on the back or are plugging into something, it could be really important to keep your eyes directly on it."
The vehicle also can be the ultimate lowrider. It can lower its belly to the ground, making it easier for astronauts in spacesuits to climb on and off. Individual wheels or sections can be raised and lowered to keep the vehicle level when driving on uneven ground.
Some, all or none of these features may be selected to be in the design of a rover that eventually goes to the moon. NASA's lunar architects currently envision pressurized rovers that would travel in pairs, two astronauts in each rover. The new prototype vehicle is meant to provide ideas as those future designs are developed.
"This rover concept changed the whole paradigm," said Diane Hope, program element manager for NASA's Exploration Technology Development Program at NASA's Langley Research Center in Hampton, Va., which sponsored the vehicle's development. "It's not something I would have expected. It provides an alternative approach."
||A Robot to Find Water and Oxygen on the Moon
A robot rover designed for prospecting within lunar craters has to operate in continual darkness at extremely cold temperatures with little power. The moon has one-sixth the gravity of Earth, so a lightweight rover will have a difficult job resisting drilling forces and remaining stable. Lunar soil, known as regolith, is abrasive and compact, so if a drill strikes ice, it likely will have the consistency of concrete. Meeting these challenges in one system requires ingenuity and teamwork. Engineers used this lunar rover to demonstrate a drill capable of digging samples of regolith. The demonstration used a laser light camera to select a site for drilling then commanded the four-wheeled rover to lower the drill and collect three-foot samples of soil and rock.
Image at left: This robot shares some features with the lunar truck, but is equipped with a drill designed to find water and oxygen-rich soil on the moon. Credit: Carnegie Mellon University
For more information about NASA's plans for a lunar outpost, visit: