Below are remarks made by Mars Exploration Rover Project Manager John Callas at the NASA Jet Propulsion Laboratory’s Spirit Celebration on July 19, 2011.
“We are here today to celebrate this great triumph of exploration, the incredible mission of this Mars rover. As bittersweet as the conclusion of Spirit’s time on Mars is for each of us, our job was to get to this day. To wear these rovers out, to leave behind no unutilized capability on the surface of Mars. For Spirit, we have done that.
What is truly remarkable is how much durability and capability Spirit had. These rovers were designed for only 90 days on the surface and one kilometer of driving distance. On her last day, Spirit had operated for 2210 Martian days, drove over 7730 meters and returned over 124 thousand images.
But it is not how long this rover lasted or how far she had driven, but how much exploration and scientific discovery she has accomplished. Spirit escaped the volcanic plains of Gusev Crater, mountaineer-ed up the Columbia Hills, survived three cold, dark Martian winters and two rover-killing dust storms, and surmounted debilitating hardware malfunctions. But out of this adversity, she made the most striking scientific discoveries that have forever changed our understanding of the Red Planet.
With the rovers originally designed only for a limited stay in the relatively comfortable environment of the Martian summer, the many years of extended operation meant these vehicles operate most of their time in the extreme environments of frigid temperatures and dark skies, well outside of their original design limits. The longevity and productivity of these rovers under such severe environmental conditions speak to the talent and dedication of the people, who designed, built, tested and operated these vehicles.
Spirit’s discoveries have changed our understanding of the Red Planet. We know now that Mars was not always a cold, dry and barren planet. That at one time liquid water flowed on it surface, sustained by a thicker atmosphere and warmer temperatures. At least, kilometer-scale lakes persisted in places. And that there were even sources of energy, hydrothermal systems, that could have supported life in this earlier habitable world.
We can’t do the impossible, make these machines operate forever. But, we have come as close to that as humans can. Spirit’s very accomplished exploration of Mars has rewritten the textbooks about the planet. Further, this rover has changed our understanding of ourselves and of our place in the Universe and approached questions of, are we alone and what is the future of this world?
But, beyond all the exploration and scientific discovery, Spirit has also given us a great intangible. Mars is no longer this distant, alien world. It is now our neighborhood. We go to work on Mars everyday.
But, let’s also remember that Spirit’s great accomplishments did not come at the expense of some vanquished foe or by outscoring some opponent. Spirit did this, we did this - to explore, to discover, to learn - for the benefit of all humankind. In that respect, these rovers represent the highest aspiration of our species.
Well done little rover. Sleep in peace. And, congratulations to you all. Thank you very much.”