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Wear and tear is a part of every vehicle's life. While NASA's Mars Curiosity Rover resembles a car in many ways, including size, it's a bit tougher to get it to a mechanic for a tune-up. That's why NASA's Jet Propulsion Laboratory (JPL) has spent 18 months working on software to upload to the rover on Mars, with the hopes that it will help give it some new life.
Curiosity's wheels started wearing down in 2013, but JPL scientists have been anticipating that long before. The rugged Martian terrain, for all its beauty, is tough when it gets jagged.On a flat surface, Curiosity's six wheels, which are called grousers, move at the same speed. But when a wheel goes over uneven terrain, the incline causes the wheels behind or in front of it to start slipping, as NASA explains.
The slipping problem grows exponentially when Curiosity is trying to get past a sharp or jagged boulder. "If it's a pointed rock, it's more likely to penetrate the skin between the wheel grousers," says Art Rankin of JPL, the test team lead for the traction control software. "The wheel wear has been cause for concern, and although we estimate they have years of life still in them, we do want to reduce that wear whenever possible to extend the life of the wheels."
The software, a traction control algorithm, uses real-time data to adjust each wheel's speed, reducing pressure from the rocks. It measures changes to the suspension system to determine the contact points of each wheel. Then, the software calculates the correct speed to avoid slippage, improving the rover's traction.
While wheelies are among the coolest thing one can do in a vehicle, NASA does not want Curiosity pulling off stunts, no matter how sick they may be. Every now and then, one of the rover's climbing wheel will keep rising, lifting off the actual surface of a rock until it's free-spinning. This becomes a problem because it increases the pressure placed on the wheels still on the ground. When the software notices a wheelie, it will decrease pressure on the rover's back wheels until it rights itself.
The software update will allow NASA to extend Curiosity's tour of the planet, which has already provided a wealth of knowledge about the history of Martian water.
Source: NASA
