After two years, Mars' punishing environment has certainly left its mark on NASA's Curiosity rover
Last week, as NASA's Curiosity rover was forced to abandon plans to take a 'soft route' to its destination at the base of Aeolis Mons (or Mt. Sharp), the toll the Red Planet was taking on the robot explorer was really becoming apparent.
After two Earth-years worth of driving around in the barren environment, rolling over harsh terrain and sharp rocks that haven't seen any significant kind of weathering (besides sand-blasting) in millions to billions of years, Mars is really starting to 'show' on Curiosity.
The biggest effect, and the greatest punishment, is to the rover's wheels. However, whereas the image included in last week's article showed some of the worst damage done, the effects are much more striking when shown in contrast to just after the rover arrived on the planet.
These two images show the condition of Curiosity's right front wheel, on her third Martian day (Sol) after arriving, and her 689th Sol (August 9, 2012 and August 15, 2014, respectively). The amount of dust accumulated on the rover is one thing, but the dings and scratches and tears in the wheels show the rough punishment she's been put through.
Why have her wheels undergone so much punishment? Why weren't they designed to withstand it all? Mostly, it was due to weight factors, and a bit of underestimation:
"They designed Curiosity to handle all the challenges that Spirit and Opportunity had experienced," Planetary Society senior editor Emily Lakdawalla wrote in her blog, "especially sand, which Curiosity traverses substantially better than her predecessors."
"They designed Curiosity to handle the sand traps, flat bedrock, and rocks-perched-on-sand landscapes seen by all the previous landers," she added. "They just didn't imagine the possibility of the peculiar and never-before-seen terrain type that they found in Gale crater."
"There are [places] on Earth that do have these sharp ventifacts, but we hadn't seen them on Mars and we didn't test against them," she wrote, quoting Curiosity Project Manager Jim Erickson.
For a full view of this kind of comparison, showing off just how much dust and dirt Curiosity has collected on her deck, check out The Planetary Society website (MER's Opportunity is also shown there).
One part of the rover that's fared a bit better than the rest is her mast - with its numerous cameras (2 hi-res colour Mastcams and 4 B&W Navcams, along with the 'big eye' of the ChemCam, which can fire a laser to zap various targets for analysis).
For this, it's simply a matter of proximity to the ground and lack of any large flat surface for dust to accumulate on. Her cameras are still remarkably clear and clean though, returning amazing pictures to us here on Earth.