When Opportunity was being designed, and then built, and as she was mounted on top of her rocket and then blasted from Earth, exiled to Mars, it was hoped that she would land safely and then survive for up to 90 days on the surface before failing in some way. As she flew to Mars we all pondered what might happen to her, what might end her mission. Maybe a computer glitch would claim her, or a piece of her would fail mechanically? Maybe Mars itself would kill her, by smothering her solar panels with dust, or breaking a wheel with a jagged rock? When she landed we watched her drive off her landing platform and trundle enthusiastically over to a band of finely-layered rocks, protruding from the crater wall like the fossilised bones of some ancient martian dinosaur, and celebrated when they turned out to be rocks altered by water – exactly what she had come to Mars to search for, and there they were, right in front of her nose!
And then, as Opportunity got down to work, we waited. Like schoolkids repeatedly staring at the clock as they sit an exam, or patients nervously checking their watches as they sit in a dentist’s waiting room we watched the sols tick by… ten… Twenty… Fifty…
We watched through our fingers as Opportunity approached the 90 sols line… and then crossed it. Nothing bad happened. She didn’t fall apart like a clown car. No wheels popped off to cartwheel across the martian desert, bouncing and boinging from rock to rock. Her camera mast didn’t sway and topple like the mast of a Royal navy warship hit by a cannonball during a great sea battle. She didn’t grind to a halt as her computer failed, sending her into an endless hibernation, like some martian Sleeping Beauty. She just kept going, and going, and going. She headed for, reached and explored one crater after another. She found meteorites sitting on the dusty ground like martian sculptures. She survived dust storms, harsh winters, and everything Mars could throw at her. And the sols ticked by…
But every time we went online to check out her latest images, and to see how far she had driven since the last time we’d checked, we wondered “Is today the day? Is today the day the images are blurry, or on their side, showing something has gone badly wrong, or there are no images at all? Is today the Today NASA announces that Opportunity has perished through the night, and that’s it, game over?”
Today is “Sol 4,984” for Opportunity. That means she has been on Mars for 4,984 martian days, because martian days are referred to as “sols”.
Just look at that number again… 4,984. 4… 9… 8… 4. Opportunity has been working – driving, studying, exploring, doing amazing science – for four THOUSAND, nine HUNDRED and EIGHTY FOUR days on Mars. And before we know it, barring any catastrophes, Opportunity will have been on Mars for FIVE THOUSAND DAYS.
It’s easy to put this down to Opportunity being “an incredible machine”, a technological marvel that has, like some charismatic Star Wars droid, totally independant and reliant on itself, faced and beaten the odds to survive this long in a hostile environment. That’s a lovely, romantic image, and one I have in my own head, I’ll admit. Time and time again in this blog, and in my writings and Outreach talks elsewhere over the years I have given Opportunity human qualities, feelings and resilience, and I’m okay with that; it helps non-astronomers and the general public to identify with the mission, feel involved with it, and generally “get it”.
But Opportunity is not alive. She is a machine, a construction of metal, wires and glass. Although she has some capacity for making decisions about where to drive, to she is no angst-ridden, poetry-writing AI. She is no martian Roy Batty. She has no free will, no sense of stubbornness or defiance. She has no more sense of identity or mortality, no more sense of pride or shame, no more sense of fear or bravery than the laptop, computer, phone or tablet you are reading this blog post on.
Sometimes, when reflecting on Opportunity’s ongoing success, praising her apparent immortality, we need to remind ourselves that Opportunity has only reached Sol 4,984 because of people back on Earth. She has been kept alive by the incredible work, dedication and professionalism of men and women at JPL, and elsewhere, who have worked hard all these years to drive her safely across Mars, to steer her around obstacles and between wonders. She is still sending back images only because people here on Earth work hard daily to keep her computers healthy and to maintain her communications link with Earth. She is now within touching distance of Sol 5000 only because people have fought tooth and nail for the funding needed to keep her driving across the cinnamon-sands of Mars.
Opportunity has been on Mars for fourteen years now, operated, nurtured and protected for all that time by incredible people. Out here we just see the photos of martian rocks, crater floors and pink skies take by Opportunity as she trundles about, ancient martian stones popping and scrunching beneath her wheels. What we don’t see are all the human stories behind them. Not just the years of study and exams needed to get to a position where you can even apply to join such an incredible project, but the subsequent years of training needed to learn how to do the job properly and then better. And outside of work, all the personal and family sacrifices endured over the years: the missed birthday parties and holidays, the missed school plays, music recitals, and more.
There will be people who joined the MER team as young, starry-eyed students who are now adults, married, with children. Experienced engineers, technicians and analysts who joined the mission after launch will now have grand-kids running around their legs when they visit their own children.
To the public space missions are short. A rocket goes up, and sends a probe to somewhere else. The probe then goes about its business, and eventually stops working, end of story. But to the people involved in those missions, they are like the generation ships beloved in science fiction. The people – the crew – that set off on the mission – the ship – will almost certainly not be the ones who see its end. People come and go during the lifetime of a space mission, and MER has been no different. Only one of the drivers skilfully guiding Opportunity down the channels of Perseverance Valley today was at the wheel to drive her off the ramp after she landed in Eagle Crater, almost a decade and a half ago; they are not all the same team who steered her to and then into Victoria Crater, before she set off on her long trek across the great Meridiani desert to Endeavour Crater, where she is now, sending back beautiful views like this…
So, this blog post is a personal THANK YOU to all the people involved in the MER missions, past and present, who have looked after our brave girl all these years. She is a fine rover, and is now essentially a martian, seeing as she has been on Mars far longer than she was on Earth. She might not have a physical heart of her own, but she carries the hearts of the hundreds, probably thousands of people who have made her the success she is.