(CN) – A NASA rover that discovered signs of water on Mars over a 15-year mission, widely exceeding expectations on interplanetary exploration, was declared dead Wednesday after attempts to communicate with the intrepid explorer were unsuccessful.
NASA last communicated with the solar-powered Opportunity rover on June 10, 2018, just as a planet-wide dust storm blanketed the western rim of Perseverance Valley on the Martian surface.
Scientists sent over 1,000 commands to Opportunity’s sensors Tuesday evening as part of an eight-month effort to revive the rover but were unsuccessful.
"It is because of trailblazing missions such as Opportunity that there will come a day when our brave astronauts walk on the surface of Mars," NASA’s Jim Bridenstine said in a statement. "And when that day arrives, some portion of that first footprint will be owned by the men and women of Opportunity, and a little rover that defied the odds and did so much in the name of exploration."
With dust covering the rover’s solar panels, preventing its batteries from recharging, scientists’ hope of the rover’s recovery faded precipitously, even as another wind storm in January blew some of the dust from the panels.
Opportunity, also known as MER-B, marked its 15th year on Mars on Jan. 24.
When first dropped on the Red Planet on Jan. 24, 2004, along with its twin rover Spirit, NASA only planned for Opportunity’s mission – taking photos, collecting soil samples and finding evidence of past water activity on the surface – to last 90 sols (92 earth days) over about 1,100 yards of the surface.
But the golf cart-sized explorer managed to travel about 28 miles, from Eagle Crater to the outer rim of the massive Endeavor Crater, where it found white veins of the mineral gypsum – a sign that water traveled there once through underground fractures.
The journey across Mars’ treacherous terrain was not without incident: Opportunity was frequently caught in sand ripples and lost function of various mechanisms.
In 2015, the rover lost use of its 256-megabyte flash memory. In 2017, it lost steering to its other front wheel.
The Spirit rover, which landed at Gusev Crater on the opposite side of the planet and managed to collect soil samples during its mission, was declared dead in March 2010.
The twin rovers dramatically changed scientists’ understanding about the red planet’s history.
Their missions uncovered evidence that Mars was likely wetter and warmer in the past, conditions that could have served as a cradle for life at a time when life was first emerging on Earth.
The 384-pound Opportunity explorer was the first rover to classify sedimentary rocks on a planet other than Earth. The rover identified small spheres of hematite nicknamed "blueberries" that formed late from rising, acidic groundwater on Mars.
"For more than a decade, Opportunity has been an icon in the field of planetary exploration, teaching us about Mars' ancient past as a wet, potentially habitable planet, and revealing uncharted Martian landscapes," NASA’s Thomas Zurbuchen said in the statement.
NASA affirmed in their statement Wednesday that their mission to deeply explore the red planet continues unabated, with plans to land more robots in the next few years.
The 1-ton, nuclear-powered Curiosity rover, now the only functioning NASA machine on Mars, is exploring the interior of the Gale Crater.
NASA's Mars 2020 rover and the European Space Agency's ExoMars rover will both launch in July 2020, the first rover missions designed to study signs of past microbial life on the red planet.
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