NASA has spotted fresh holes in the wheels of the Curiosity rover as it makes its way across the rugged and rocky surface of Mars.
Fortunately, the holes are not expected to hamper the progress of the mission, but they are a reminder that, 225 million kilometers (140 million miles) from Earth, our unmanned machines can be damaged beyond repair. Future missions will need to be able to deal with these issues.
We’ve seen damage to Curiosity’s wheels before, as far back as 2013. This time around, two small breaks were seen in the left middle wheel of the rover on March 19, having not previously been there in the last check on January 27. Specifically, they were in raised treads known as grousers, used by the wheel to grip the ground.
The solid aluminium wheels are 50 centimeters (20 inches) in diameter and 40 centimeters (16 inches) wide, but they are only about half the thickness of a US dime. Each has 19 grousers, slightly thicker treads that extend about 0.75 centimeters (0.25 inches) further out.
Testing on the wheels has shown that once three grousers on a wheel breaks, it will have reached about 60 percent of its useful life. However, these latest findings are not expected to impact the mission as a whole.
“This is an expected part of the life cycle of the wheels and, at this point, does not change our current science plans or diminish our chances of studying key transitions in mineralogy higher on Mount Sharp,” said Curiosity Project Scientist Ashwin Vasavada from NASA’s Jet Propulsion Laboratory (JPL) in California in a statement.
Curiosity is continuing to make its way up Mount Sharp, a central peak in the middle of Gale Crater. It is about 6 kilometers (3.7 miles) from the highest point it is scheduled to reach, with the damage to the wheels not expected to affect reaching this destination.
How machinery degrades on Mars is actually quite an interesting question. With a much thinner atmosphere, but also home to widespread dust storms, machinery does gradually break down over time. The Spirit rover, for example, got stuck in loose soil and ultimately lost power in 2010.
One of the proposed landing sites for NASA’s upcoming 2020 Mars rover is actually Columbia Hills, the same region that Spirit is in. If this site is picked, NASA’s new rover may get a chance to study its older ancestor and take a look at what the Martian environment has done to this unprotected piece of machinery.