02.27.08

Brandi Dean
Johnson Space Center, Houston
281-244-1403

Stephanie Schierholz
Headquarters, Washington
202-358-4997/2087

RELEASE: H08-068

NASA'S NEWEST CONCEPT VEHICLE TAKES OFF-ROADING OUT OF THIS WORLD

HOUSTON - 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 available is gold. 

But NASA's latest concept vehicle is meant to go way off-road, as in 
240,000 miles from the nearest pavement, and drive 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 more distant destinations. 

Built at NASA's Johnson Space Center, Houston, the new design is one 
concept for a future lunar truck. 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. 

&quot;To be honest with you, it was scary when we started,&quot; said 
Lucien Junkin, a Johnson robotics engineer and the design lead for 
the prototype rover. &quot;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.&quot; 

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 using 
the remaining five. 

With the number of wheels decided, the next question was 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 several 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. 

&quot;The Apollo astronauts couldn't back up at all because they 
couldn't see where they were going in reverse,&quot; said Rob 
Ambrose, assistant chief of the Automation, Robotics and Simulation 
Division at Johnson. &quot;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.&quot; 

The vehicle also can be the ultimate low-rider. 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 for the design of 
a rover that eventually goes to the moon. NASA's lunar architects 
currently envision pressurized rovers that would travel in pairs, 
with two astronauts in each rover. The new prototype vehicle is meant 
to provide ideas as those future designs are developed. 

&quot;This rover concept changed the whole paradigm,&quot; 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. &quot;It's not 
something I would have expected. It provides an alternative 
approach.&quot; 

To view images of the lunar truck and another rover technology in 
development, visit: 

http://www.nasa.gov/mission_pages/constellation/main/lunar_truck.html 

A Video File of the lunar truck will air on NASA Television. For 
schedule and downlink information, visit: 

http://www.nasa.gov/ntv

	
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