Opportunity: The Nasa Mars Exploration rover that kept on going

During 14 years of intrepid exploration across Mars, it advanced human knowledge by confirming that water once flowed on the red planet—but Nasa’s Opportunity rover has analysed its last soil sample.

The US space agency lost contact with the rover during a dust storm in June and it was declared officially dead on 13 February, ending one of the most fruitful missions in the history of space exploration.

Unable to recharge its batteries, Opportunity, known affectionately as Oppy, left hundreds of messages from Earth unanswered over the months, and Nasa said it made its last attempt at contact on 12 February evening. “I declare the Opportunity mission as complete," Thomas Zurbuchen, associate administrator of Nasa’s science mission directorate, told a news conference at the mission headquarters in Pasadena, California. The community of researchers and engineers involved in the programme were in mourning. “It is a hard day," said John Callas, manager of the Mars Exploration Rover project. “Even though it is a machine and we’re saying goodbye, it’s very hard and it’s very poignant."

“Don’t be sad it’s over, be proud it taught us so much," former president Barack Obama tweeted on 14 February. “Congrats to all the men and women of @NASA on a @MarsRovers mission that beat all expectations, inspired a new generation of Americans, and demands we keep investing in science that pushes the boundaries of human knowledge."

The nostalgia extended across the generations of scientists who have handled the plucky little adventurer.

“Godspeed, Opportunity," tweeted Keri Bean, who had the “privilege" of sending the final message to the robot.

The programme has had an extraordinary record of success: 28.1 miles traversed, more than the Soviet Union’s Lunokhod 2 moon rover during the 1970s and more than the rover US astronauts took to the moon on the Apollo 17 mission in 1972. “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 administrator Jim Bridenstine said in a statement. Opportunity sent back 217,594 images from Mars, all of which were made available on the internet.

“For the public, the big change was that Mars became a dynamic place, and it was a place that you could explore every day," said Emily Lakdawalla, an expert on space exploration and senior editor at The Planetary Society. “The fact that this rover was so mobile, it seemed like an animate creature," she said. “Plus it has this perspective on the Martian surface that’s very human-like."

Opportunity landed on an immense plain and spent half its life there, traversing flat expanses. It was there, using geological instruments, that it confirmed liquid water was once present on Mars. During the second part of its life on Mars, Opportunity climbed to the edge of the crater Endeavour, taking spectacular panoramic images—and discovering veins of gypsum, additional proof that water once flowed among the Martian rocks. Opportunity’s twin, Spirit, landed three weeks ahead of it, and was active until it expired in 2010. The two far exceeded the goals of their creators: In theory, their missions were supposed to last 90 days.