14 DAY TRIAL // Dust is plenty, however more electric power would be pretty nice, since electronics don't run on 'dirt power'. That is true, but so is the following affirmation: 90 is not equal to 1,460! 1,460 days have passed since the Martian rover Spirit landed on the surface of the Red Planet, meaning exactly four Earth years and, after exceeding almost 17 times the expected lifetime, the exploration vehicle is still going strong, running from an imminent death.
Originally designed for a mission that was scheduled to last only 90 days, the Spirit rover celebrates today its 4th year on the surface of Mars, equivalent to 2.25 Martian years or 1,501 Martian days, during which time NASA engineers exploited it to its maximum capacity. Its sibling, the rover Opportunity that landed on the surface of the planet only 21 days after Spirit, will celebrate its 4th year on Mars on January 25th.
Since they were deployed, the two rovers have covered a distance of about 19.1 kilometers, have captured pictures of more than 210,000 images of the surface, which if converted to a more earthly measuring unit would be equivalent to about 55 DVD movies of uncompressed data, have executed more than one hundred geological studies and have contributed to finding evidence of past existent liquid water on the surface of Mars.
Though crippled by multiple mechanical instruments and software failures, the rovers have faced great dangers this year, during the fearsome dust storms that raged across the surface of Mars for more than a month, and that reduced their sunlight harvesting capabilities to levels that almost drove the two to a permanent standstill. Nevertheless, mild wind gusts partially cleared the solar panels of the rovers, ensuring enough power to safely operate them.
Unlike Opportunity, which has it solar panels relatively dust-free, Spirit was forced to move towards the northern end of the Home Plate plateau, in order to reach a designated spot with a 25 degrees angle tilt towards the Sun that could provide more sunlight. However, during its drive, Spirit got stuck for more than a week in loose soil, losing precious time; thus, engineers decided to find an alternative shelter for the battered vehicle. Though NASA is trying to squeeze as much information as possible from Spirit, they are conscious that the solar panels of the rover will not get cleaned any time soon, thus they consider it pretty much done for.
On the other hand, Opportunity has great chances of remaining in operation for an indefinite amount of time, despite the fact that it has also suffered multiple malfunctions. So far, it can operate on the Martian surface, whether it's summer or winter, and does not require sunlight optimization, as Spirit does. Opportunity is scheduled to execute a series of mission involving, scanning the atmosphere for evidence of water-crystals, making atmospheric measurements and, why not, the possible asteroid impact that might take place at the end of this month.