It keeps going and going.

NASA's Opportunity rover has logged a total of more than 30 kilometers (18.64 miles) of travel on Mars since 2004, thanks to a recent drive of 482 feet (146.8 meters) that put it past the 30 km milestone.

In a report, NASA noted the distance is "50 times the distance originally planned for the mission and more than 12 times the distance racehorses will run next week at the Belmont Stakes."

The twin rover Spirit has been out of communication with Earth since March 2010 after driving 4.8 miles, and NASA finally gave up on trying to communicate with it just last month. But Opportunity is still rolling along and taking photos of nearby craters, such as a 30-foot hole informally dubbed "Skylab" after the first U.S. space station.

Opportunity has been investigating exposed rock outcroppings on a long journey to Endeavour, an enormous impact crater measuring 14 miles across that's now only about 2 miles away.

The rover's right front wheel motor has been drawing more power than the other wheels, and intermittent cosmic rays have delayed Opportunity's progress, but its extended performance after its initial three-month mission has been remarkable.

Thanks to the painstaking care of NASA managers, it has survived a sand trap, dust storms, and numerous other hazards. We hope Opportunity's first landfall at Endeavour comes soon.