New Moon Rover Mixes Old-School Smarts With Latest Tech
National Geographic News
|October 23, 2008|
With six-wheel drive, active suspension, and computerized navigation, a new battery-powered truck being field tested this week in Arizona sounds like the next generation of sport-utility vehicles.
But when the final model rolls out in 2019, only an exclusive group of highly trained professionals will get to drive it—the next astronauts to land on the moon.
The new lunar rover, informally known as the Chariot, is a prototype being developed as part of NASA's Constellation program, which aims to put people back on the moon by 2020.
The current version combines 35 years of technological advances with lessons learned from the original "moon buggies" used during the Apollo missions of the 1970s.
One of the biggest modifications is an optional pressurized cabin that comes fully equipped with beds, a pantry, a waste-management system, and a pair of space suits, allowing astronauts to live and work "on the road" for up to two weeks.
"It's important to keep the crew happy," noted Mike Gernhardt, a veteran NASA astronaut who is helping design the Chariot at the Johnson Space Center in Houston, Texas.
"As long as the food's good and the seats are comfortable, you can put up with a lot."
NASA sent up its first lunar roving vehicle—an open, four-wheeled buggy—as part of the Apollo 15 mission in 1971.
Roving crew members collected a variety of samples to bring back to Earth, including the Genesis rock, a chunk of the lunar crust believed to date back four billion years to the birth of the moon.
NASA ultimately sent four rovers to the moon during the Apollo program, and the hardy vehicles were generally hailed as successes.
But some aspects of the buggies' design proved to be less than ideal.
For example, a T-shaped stick in between the seats was the only steering control. Like an Atari joystick, the system was simple and intuitive: Push forward to go forward, backward to brake, and left or right to turn.
The placement, however, was a tight fit for astronauts in their bulky space suits. (See related photos of a skintight next-generation space suit designed at MIT.)
"Every time Charlie bumped my arm, I moved the steering wheel," said John Young, a retired NASA astronaut who, with colleague Charles Duke, drove a lunar rover during Apollo 16 in 1972.
Also, the rover's range was limited by its two nonrechargeable 36-volt batteries.
"You can't run out of electricity on the moon, that would be a killer," Young said. The farthest any of the four buggies ever got from the lunar module was 4.7 miles (7.6 kilometers).
In addition, the buggy became unstable near its top speed of 7.5 miles (12 kilometers) an hour, noted Robert Ambrose, NASA's lead engineer for mobility of the new lunar rover.
"It started doing something called 'porpoising' and they sorta lost control of it," Ambrose said, referring to the older vehicle's tendency to bounce and tilt wildly.
Does It Come With Leather Seats?
Ambrose and other engineers have been designing the new rover in part based on tips from Apollo astronauts.
To overcome the porpoising problem, for instance, the Chariot has a longer wheelbase and is outfitted with the same automatic stability control used to keep today's sport-utility vehicles from rolling over.
Steering is controlled by a computerized navigation system, and all six wheels can turn in any direction or be individually lifted for greater maneuverability.
The craft also has two gears—first gear tops out at 3 miles (5 kilometers) an hour, while second gear can safely reach 12 miles (20 kilometers) an hour.
Rechargeable lithium-ion batteries allow the craft to venture up to 62 miles (100 kilometers) and back before needing a pit stop at a solar-power station.
One of the more unusual innovations is a pair of slip-on space suits attached to the back of the pressurized cabin.
Rather than taking up room with a full-size airlock, a "plainclothes" astronaut simply slides into an empty suit, pulls a lever to close the hatch and detach, and walks away.
The process can then be done in reverse to re-enter the cabin.
"This is a totally different way of doing business in spacewalking," Ambrose said.
The rover will need to pass several rounds of technical tests and budget reviews between now and 2019 before the design is finalized.
The entire Constellation program, which is slated to cost U.S. $104 billion, has already hit a few roadblocks, including a one-year delay for the first crewed test flight of the launch vehicle and lander, originally slated for 2013.
It also remains to be seen what a new U.S. president will mean for the project.
Last year Senator Barack Obama's campaign announced plans for an $18-billion-a-year education reform that would be paid for, in part, by delaying Constellation for five years.
And while Senator John McCain's campaign says that he has supported funding for a return to the moon, the presidential hopeful recently said he would reduce the federal deficit by freezing for a year all discretionary funding—NASA included.
For now the space agency is holding firm to its 2020 deadline, and projects like the lunar rover are continuing forward with safety and durability as top concerns.
"It'll probably be two or three iterations of design [before] we're going to have it nailed well enough to ask astronauts to risk their lives," Ambrose said.
The field tests underway this weekend will give an astronaut and a geologist a chance to take the current version of the Chariot for a day-long spin in the Arizona desert, simulating the rocky, dusty conditions they would encounter on the moon.
In addition to testing the rover's technology, the road trip will give its passengers a chance to rate the vehicle for comfort—a major safety concern.
"I'm no sociologist," Ambrose said, "but I imagine that if you're cramped and uncomfortable, you're not going to be a very good driver."
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