As a matter of record at this time, Spirit has spent 738 sols on Mars and traveled some four miles, and Opportunity, at 718 sols, has traversed a bit more than four miles. To put this accomplishment into perspective, Spirit is 648 sols and Opportunity 628 sols past warranty,• respectively, an indication of just how well they were planned, designed, and assembled. These are very impressive stats considering the hostile environment that surrounds the rovers as the seasons change from summer to winter on Mars.
Not intended just for level-terrain prospecting, Spirit embarked on a long journey to Husband Hill, which is as high as the Statue of Liberty, and proceeded to climb to the top through the careful steering of the rover driver back on earth. On the way up the hill, Spirit was able to justify the primary reason for its long journey from earth to Mars: It found rocks that at one time contained or were formed in water.
Spirit made other significant discoveries including molten rocks born as a result of meteorite impacts, rocks formed from erupting volcanoes, and the accompanying lava flows. On its journey, Spirit has taken more than 70,000 images, giving our scientists an impressive look into the history of our neighbor. Not yet ready for the junkyard, Spirit is scheduled to head south to yet another foreboding territory, aptly named the Promised Land.
On the other side of the planet, Opportunity was making equally impressive finds as it traveled from crater to crater. Practically from the beginning of its Martian journey, Opportunity provided images and data that clearly showed the effects of water in the rock formations. As Opportunity made its way into deeper and deeper craters, scientists were able to determine by examining different layers of deposits that water had been present, not just once, but at several times over the history of the planet. One unanswered question remains: Is there ice buried deep below the Martian surface? Future missions undoubtedly will find out.
As I recall, the rover program had some very tight budget constraints and yet, in spite of limited funding, the engineers and scientists working on the project have achieved phenomenal successes. Unquestionably, the results have far surpassed everyone's expectations. And if it weren t for these talented technologists, the outcome of the program most assuredly would have been quite different.
