For a rover with an initial mission duration of just three months, the NASA Opportuny rover has greatly exceeded its lifespan.
On Monday, a seasoned rover marks the twelfth anniversary (yes, 12 Earth years or 144 months) on the Red Planet. It was a hard road for a robot, but it still contributes to science. Moreover, it does this in the most aggressive season of the Martian year, which lasts approximately 687 Earth days.
January 2 in the southern hemisphere of Mars is the winter solstice, marking the shortest and, therefore, the darkest day of the year Opportunity. For the rover, working on solar energy, this is not the best time. Opportunity needs sunlight to charge its batteries, so during a limited daylight hours, rover drivers should set it at an optimal angle to catch as much sunlight as possible.
But the insanely extended mission had some problems. Martian dust was collected on solar panels, subsequently limiting the amount of sunlight used to charge batteries. Only recently, the mission’s engineers were concerned about the state of the rover’s solar panels; they are so dusty that the energy input from the sun is reduced to a minimum.
After the Martian nature intervened and provided for Opportuny, surprisingly in time, he needed the “cleaning measures”. Purification measures have become a crucial, but unplanned component of a long-term, solar-powered mission on the Martian surface. Opportunity and his brother, the rover Spirit, processed the Martian wind, blowing their bodies and removing part of the dusty layer, giving them extra power. The latest cleanup of Opportunity took place at the end of 2015, before diving into the Martian winter, thus allowing the Mars Rover to continue its valuable work in 2016. “Opportunity remained very active this year, in part because its solar panels were much cleaner than last winters,” said Mars Exploration Rover project manager at NASA Pasadena, California, from NASA news feeds, said John Callas.
Since landing on the Meridian Plateau on January 24, 2004, Opportunity has provided some clues to the wet past of the Martian environment, explored the unique geology and dynamics of the planet's atmosphere. Suddenly, the long-term presence of the Mars rover on Mars taught NASA some things in engineering and working with aging robotics, on a planet that is 10 million miles away.
The greatest test of old age, at the moment, is not breaking the measuring devices of the rover or the freezing of the drives of its wheels, and in fact, its flash memory. The Opportunity flash memory (not like a hard disk on a computer) not created for a multi-year mission began to wear out, and NASA engineers began working on a strategy for bypassing damaged memory blocks, switching to a volatile memory of the rover (i.e., a similar computer memory, which does not store information).
Despite the obvious limitations in what Opportunity can accomplish, it still makes a valuable contribution to science. More recently, the rover used a tool that erases a stone in its mechanical arm to scrape a circle in the surface of a stone called “Private John Potts” in “Marathon Valley”, so named because it found the “finish line” of Opportuny’s 26-mile journey from the moment of landing. in 2004. From the material collected from the surface of the rock, other tools that are in the mechanical arm study its composition and help geologists to understand the conditions under which this rock was formed. The Marathon Valley is located in the Ring of the Crater Endeavor, investigated by the rover in 2011. The orbital observations of the valley showed interesting clay deposits (formed when the Martian environment was much wetter than it is now), which Opportunity explored.
“With the increase in power level, we expect to complete work in the Marathon Valley this year, and to continue the path of Opportunity,” concluded Callas.
It may look like the fight against aging, but Opportunity certainly does not finish its work on Mars.