Artist concept of the Dawn spacecraft near Mars. Image credit: NASA/JPL
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Launched in September of 2007, and propelled by any one of a trio of hyper-efficient ion engines, NASA’s Dawn spacecraft passed the orbit of Mars last summer. At that time, the asteroid belt (where Dawn’s two targets, asteroid Vesta and the dwarf planet Ceres reside), had never been closer. In early July the spacecraft began to lose altitude, falling back towards the inner solar system. Then on October 31, 2008, after 270 days of almost continuous thrusting, the ion drive turned off.
Artist concept showing one of two Mars Exploration Rovers. Image credit: NASA/JPL-Caltech/Cornell University UPDATED on Jan. 29: Spirit Working Well While Diagnostics Continue
Diagnostic activities performed by Spirit on Thursday, Jan. 29 narrowed the range of factors that may have contributed to its unexpected behavior earlier in the week. No clear explanation has been established yet. Spirit is healthy and responding to commands. It recorded and returned images of nearby scientific targets. The rover team plans further diagnostics on Friday of Spirit’s inertial measurement unit — a combined gyroscope-and-accelerometer device that measures rover movements and attitude. Spirit may resume driving over the weekend.
