When Will NASA's Mars Rovers Fade? Not Tonight

Any day now one of my dearest friends – perhaps even two of them – will die, leaving a huge hole in my world. Even though I've imagined and rehearsed it in my mind countless times I don't know how I'll react when I hear the news, which I've known is coming for a couple of years now; all I know is that when the awful day comes, and I read the announcement, I'll feel like a part of me has died too.

So who are these beloved friends? Treasured schoolmates from years ago, suffering from some terrible illness? Work colleagues, injured in a horrible accident and left lying in a bed, with drips in their arms and machines beeping around them like R2D2? No. They're machines. Robots. Or, to be more precise, rovers. I know them as "Lame Spirit" and "Oppy," but you'll know them better as 'Spirit' and 'Opportunity,' the Mars Exploration Rovers, and to me, they've developed characters and personalities every bit as loveable and real as Artoo's. They're like Serenitys on wheels.

I'm proud of them and all they've achieved, those plucky, apparently immortal machines. They arrived on Mars all those years ago so bright and so shiny, their clean metalwork flashing in the Martian sun as they emerged like aluminum butterflies from their cocoons. Now they're weary and worn, and each day they wake seems like a miracle. Oppy is still in pretty good shape as she works her way around the serrated rim of Victoria Crater, but on the other side of Mars my poor gal Spirit is suffering. Smothered in Sun-dimming, circuit-clogging dust and dragging a frozen wheel behind her as she hauls herself around Homeplate, she's on borrowed time and she knows it.

In fact, everyone following their incredible mission – from the white bunny-suited techs who physically built the rovers, to the Mars nuts like me who follow their journeys of exploration daily on our flickering PC screens – knows that both rovers are living charmed lives now. Both rovers have now survived on Mars ten times longer than they were expected to, so every day (sorry, every 'sol') is a bonus. If both died while I wrote these very words, they would have fulfilled their mission a thousand times over, and no-one would consider their passing premature.

Except people like me.

Scattered around this achingly beautiful blue and white globe – by now pale-skinned and square-eyed after countless hours spent locked indoors staring at flickering monitors – there are many thousands of people who have, since Sol 1, been the rovers' constant companions as they rolled across the rugged Martian landscape. We've walked patiently and faithfully alongside these incredible, death-defying space age Lewis and Clarks as they trundled across the wide open spaces of Barsoom.

Sitting here, typing this, I can remember keeping Oppy company as she explored the rubble-strewn interiors of Eagle and then Endurance crater, before helping her weave her way around bank after endless bank of deathtrap dunes of butterscotch-hued dust on her epic trek to Meridiani's Deep South. I was there, brushing fine grains of dust from Spirit's aching back as she trundled past wind-sculpted outcrops of ancient, jagged rock on her way up the rugged slopes of Husband Hill, urging her onwards, telling her she can do it, she Can Do It, she just has to keep going ? and after triumphantly reaching the Hill's summit with her, I paused with her there, with my hands resting on her dust-scratched solar panels, staring down with her in wide-eyed wonder at the rusted world below?

Of course, I didn't do all those things really, but it felt like it as I sat here, mouse click-a-clicking on one weblink after another. Looking at the latest images from the rovers has become every much a part of my daily routine as brushing my teeth or swearing at a politician's lies on TV. I get up, and before I go to work – before I've even rubbed the sleep out of my eyes – I've booted up my PC, gone online and headed straight to Exploratorium to see if any new images came down thru the night. Back from work hours later and before my bag has even hit the floor I'm checking for new pictures again, letting out a disappointed sigh if there are none to be found, celebrating with a "Yes!!" if an as yet unclicked link, written in glorious bright blue, appears at the foot of the list?

I now have two homes. In the Real World I have a flat, with shelves groaning under the weight of copies of books about Mars and walls decorated with printouts of MER pictures. In the world we so quaintly used to call Cyberspace I live on a forum called Unmanned Spaceflight.com, now one of the world's most respected meeting places for people with a passion for space exploration. There we talk about the rovers and their discoveries daily, discuss what we can see – and sometimes think we can see! – on the new images, and even post our own images, Photoshop merged and colorized versions of the already-spectacular black and white raw images enjoyed by Everyone Else. Every time I log on to UMSF I feel as welcome and comfortable as Norm walking through the door in Cheers.

And every time I log on I feel a cold nugget of fear in the pit of my stomach as I wonder if this is the time I read that one of my friends has died.

I'm heading there now, just as soon as I've finished writing this.

Not tonight. Please, not tonight?

• Red Planet Rovers: Still Stalking Science
• Mars Rover Special Report
• All About Mars' Watery Past

NOTE: The views of this article are the author's and do not reflect the policies of the National Space Society.

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