Not a single person would have thought it possible or even probable that the two Mars rovers could still be alive and well today after more than six years of traversing and exploring the surface of the Red Planet. Originally designed to operate for an approximately three-month prime mission, Spirit and Opportunity are still performing incredibly beyond all expectations. Actually, through recent software uploads, Opportunity now is making its own decisions on what further tasks should be undertaken when it encounters an object exhibiting particular characteristics.
In a recent article by Darren Quick in Gizmag, the new software, Autonomous Exploration for Gathering Increased Science (AEGIS), enables Opportunity’s computer to “examine images that the rover takes with its wide-angle navigation camera after a drive, and recognize rocks that meet specified criteria, such as rounded shape or light color. It can then center its narrower-angle panoramic camera on the chosen target and take multiple images through color filters.”
In early March of this year, the final checkout of the AEGIS was performed. As reported in the Mission Manager Reports, Opportunity was completing the circumnavigation of the crater Concepción while AEGIS was analyzing images from the navigation camera for cobbles, rocks based on size and brightness. Upon finding a cobble that met the prescribed criteria, the software automatically took a high-quality picture of the target, verifying the checkout.
Before AEGIS, as noted in the article, the information collected by Opportunity as it drove over the Mars terrain had to be transmitted back to earth to be post-analyzed by the scientists. If the researchers noted something of interest in the recorded data, then they would drive Opportunity back to that location to take some additional images. The new software lessens the need for extensive post-analysis on the ground.
According to the article, previous software upgrades to the rovers have enabled them to perform certain tasks on their own to safely navigate across the Mars terrain. For instance, they can make decisions as to which is the best route to follow when maneuvering around large objects. In addition, the rovers now know how far to extend their robotic arms enabling them to make precise contact with a rock, for example.
Also, other nontechnical forces are helping the rovers stay alive. Uncharacteristically, the Mars environment is extending the operational life of the rovers. As you may expect, while the rovers roll over the surface, the Martian dust tends to collect on the solar panels. With dust on the panels, they become less efficient. However, the Mars winds are doing a pretty good job of blowing the dust from the panels, helping to restore the panels’ efficiency.
There are some rather interesting conclusions that might be explored and debated concerning the magnificent success these two robotic marvels have enjoyed since early 2004. Obviously, the rover developers, not having to pay particular attention to lengthy long-term operational demands, could well design circuits and specify components and mechanical parts and the like that don’t have to function flawlessly for extended periods of time. Possibly mean time between failure was not even a consideration in their calculations.
Not requiring highly reliable parts and using technology from previous landers should have resulted in a lot of money saved in the design and construction of the rovers. Parts designed for a three-month prime mission should be cheaper and more readily available than parts for a three-year mission.
But, might there have been a completely different goal envisioned by the rover team from the very beginning? Considering the current longevity of the program along with the real possibility of many more months of operation, is it possible the designers actually conceived and planned the development of the rovers so they would vastly exceed the original intent of the project? Did they really foresee not a three-month prime mission, but a much longer operational period of one year, three years, and more? Did they purposely set out to overdesign the rovers, paying little or no attention to the original mission requirements? I personally don’t think this is the case, but the thought does cross one’s mind as Opportunity and Spirit travel merrily on the planet with little signs of slowing down.
Without question, the entire Mars rover team is to be congratulated on the tremendous success of their program. They have demonstrated that space exploration can be truly gratifying and the results can surpass even their most wildly optimistic expectations.
So, maybe NASA and its contractors should use this three-month mission operational philosophy as a basis for all future unmanned (do we dare think some manned?) space exploration projects? Design and build them for short-term life, and they most likely will perform admirably for years.