NASA’s Mars Exploration Rovers, Spirit and Opportunity, were only supposed to last 90 days on the Red Planet. Defying the odds, they have survived nearly three (Earth) years. Spirit landed first, and today it experiences its 1,000th Martian day (each so-called sol is 37 minutes longer than an Earth day).
Spirit won't be dancing a celebratory jig, however. Mission controllers are keeping it still. Mars is currently in conjunction on the far side of the Sun as seen from Earth, making it impossible for the Jet Propulsion Laboratory to communicate reliably with the rovers. Thus both Spirit and Opportunity will be staying put and merely snapping some photos, taking other measurements, and beaming them to Earth. Most of the data will likely make it through the solar interference. The rovers will remain incommunicado until the planet moves clear of conjunction on sol 1,015 (November 10th).
Spirit and Opportunity remain in rather good shape considering the harsh alien environment. Spirit has driven nearly 6.9 kilometers (4.3 miles) and is only slightly hobbled by a wheel that no longer turns. Spirit can no longer drill into surfaces of rocks because the Rock Abrasion Tool (RAT) has no more abrasives. In its sprint to reach Victoria Crater, Opportunity has racked up 9.4 km. Its RAT still has enough teeth left to grind a few more rocks, but the instrument-laden arm suffers from a bit of arthritis.