Spirit and Opportunity: A Tale of Two Rovers
01.12.09
Green board. 5, 4, 3, 2, 1.
Engine start and lift-off of the Delta II rocket carrying the Spirit from Earth to planet Mars.
3, 2. Main engine start. Zero and lift-off of the Delta rocket with Opportunity. A chance to explore and unlock the secrets of our neighboring planet.
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We’re on Mars everybody!
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Steven Squyres: The two landing sites are very different. And we’ve used the two vehicles very differently since we arrived there. Opportunity’s landing site is smooth and flat. You can drive for miles. It’s all very easy. Spirit’s landing site is very rugged, very rocky. Moving around is much more difficult. Spirit’s landing site is at a higher latitude, so the winters are much more severe. And so coaxing that vehicle through a cold, dark Martian winter is a much tougher job than it is for Opportunity.
Ashley Stroupe: Now they are well named. Opportunity really has been incredibly opportunistic and lucky. It basically found water from its lander. It’s been able to do all kinds of things because it was lucky, like being able to drive into these craters. It found it’s own heat shield. And we were able to examine for the first time a heat shield that was used on another planet because it happened to land nearby. Spirit really has had to have a lot of spirit to keep going. It’s been the little rover that could, in a way. It’s had to work very hard for all of its discoveries.
John Callas: These are phenomenal vehicles. So well engineered and designed and built that they have been able to last. But they’ve been able to do this very challenging dangerous exploration of the surface. I mean, they are very much intrepid explorers. You know, our proxies on the surface of Mars. Going forth to explore this hostile and alien world.
Steven Squyres: Mars is a nasty place. And one of the things that Mars does is every so often, blows up into a global dust storm. Our third summer on Mars it happened. Storm went global. Blocked out the sky. If you were sitting at the surface of Mars where Opportunity was the amount of direct sunlight hitting the solar panels was less than one percent of what it would be with a clear atmosphere. You can barely tell where the sun was in the sky. This is a very scary thing if you are a solar powered vehicle obviously. It was this kind of helpless feeling. You’re sitting there, and Mars is doing what it does, and it’s like the planet’s trying to kill our rovers. And we had this very challenging job of managing this tiny amount of power that we had on board the vehicle.
The bad wheel on Spirit has been both a curse and, as it turns out, a blessing. The curse part is obvious. It’s very hard to drive that vehicle now. Spirit’s in some pretty tough terrain anyway, and now you’re dragging this dead wheel through the dirt. Ten meters is a really good day for Spirit these days. But, it’s had a wonderful silver lining.
Scott Maxwell: These trenches that she was digging, that just sort of naturally happened by dragging a wheel through the dirt, had these bright patches at the bottom. Some of those patches turned out to have a very high like 90 percent silica content. And the way you get a high 90 percent silica content is lots of water activity. So by dragging Spirit’s broken wheel around she actually turned up some of the best evidence we’ve found of water on either vehicle so far on Mars.
Steven Squyres: Getting to Victoria was great! It was 21 months of trudging endlessly across these plains and hardly seeing the scenery change at all. And then one day we’re right at the rim of it and, phooww. There’s just this spectacular scenery, this fabulous geology just laid out in front of us and yah, the combination of just what a glorious view it was plus so much effort that went into getting there. Pulling up to the rim of Victoria was to me one of the really special moments in the whole mission.
How do I feel about the fact that it’s gone on for five years? Exhausted. (Laughter) Really tired! I thought we were going to get maybe six months out of these things. I never thought we’d get five years.
John Callas: I was one of the optimists that felt the rovers would survive the first winter, and that we would have an extended mission. But I never though they would last through three Martian winters and continue to explore for five years.
Scott Maxwell: I never in my wildest imagination believed it was going to go on for five years and give me this opportunity to see so much of Mars and for so long. And to learn so much about, not only about the vehicles, but about the science of Mars and about the area in which they landed, and to just have this opportunity that I thought was going to be a terrific little short honeymoon just go on and on and on and on and on. And just get better all the time.
Steven Squyres: We’re going to push these rovers as hard as we can, for as long as we can. As long as they keep on moving, as long as they keep making discoveries, it is our responsibility to push these vehicles until they drop.
John Callas: The rovers have made Mars familiar to us. You know, prior to their landing it was this mysterious place. And even though we had had successful orbiting missions, we didn’t have a human perspective on Mars. It was always a very distant perspective. The rovers have given us that human perspective, and now it is familiar to us.
Steven Squyres: Mars is such a complicated place, and these are such capable vehicles, that there will never come a time when we’re done. Regardless of when this mission ends…whether it’s tomorrow, or five years from now. There’s always going to be some wonderful, tantalizing thing just beyond our reach that we didn’t quite get to.
Jessica Collisson: When our children and grandchildren bring home that science book where it says there is evidence of liquid water on Mars, to know that you helped build and operate and direct the rover to that spot, yeah, that’s very rewarding.
Steven Squyres: We’re tired, but there’s just nothing more fun than getting up in the morning and going to work and seeing something nobody has ever seen before. And then deciding, all of us sit down together today on this planet to decide what’s going to happen tomorrow on that planet. That’s fun.
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