Thursday, February 14, 2019

An everlasting itch for things remote


So it's official. Today, eight months after a raging dust storm on Mars silenced the Opportunity Rover, NASA pronounced it dead. A day earlier they'd sent a final "wake-up" call, to which it did not respond, just as it had not to earlier calls after the storm lifted.

Opportunity and its twin, Spirit, working on opposite sides of the planet, were designed to last 90 days: technically 90 Sol's, a Sol being a Martian day, which is 37 minutes longer than an Earth day.

It has been fifteen years since they landed, a testament to the engineers who built and then controlled them, steering them out of untold numbers of deathtraps since 2004.

Even at the start, they did not so much land as bounce. After using a heatshield to punch through the Martian atmosphere at 20,000 km/h, they would drop away from the "mother" craft on a line, the mother popped a chute and then used retro-rockets to slow down almost to a complete stop above the surface. Five seconds before hitting the surface, each vehicle inflated a set of tough rubber balloons that completely encased it - and then cut the cord to "mother", dropping to the surface and bouncing as high as a five story building, with 40g impact the first time, bouncing a few more times and finally coming to rest, after which the "airbags" deflated to expose the rover and allow it to be on its merry way.


As crazy as it sounds this had worked before with the little 1997 Pathfinder / Soujourner rover, but it was not used for the latest rover, Curiosity, which weighed 900 kilos.

Spirit died in 2010 after getting stuck in yet another sandtrap and being unable to orient its solar panels for the approaching Martian Winter. Both it and Opportunity had already survived numerous dust storms that had dropped their power supplies close to zero, providing barely enough power to keep the electronics from freezing.

At one stage, Spirit's front right wheel simply froze, and for the rest of its life, the rover was forced to drive backwards, dragging the wheel around like a lame animal. But in the usual paradox of discovery, one day in 2006,  the stuck wheel dragged through a thick layer of dust in a crater that Spirit was crossing, revealing a bright, white layer of silica. On earth there are only two environments where silica can be formed; a hot spring, where the silica is dissolved away and deposited somewhere else, or a fumarole where acidic steam rises through cracks, dissolving other minerals and leaving mostly silica. On Earth, both environments teem with life. It was a hell of a discovery, and something the machine was not designed to find.

Opportunity had an easier time of it, driving across a lot of stone as it explored four different craters, putting 45km on the clock, the greatest distance travelled by any rover on any planet. It nailed down the water theory too, not just via spot mineral analysis, but extensive readings over distances that proved there had been kilometre wide bodies of water - actual lakes - on the Martian surface.

As is often the case, the humans using the machines got very attached to them, to the extent that when JPL managers suggested that some Spirit members might like to transfer to Opportunity, they all said no, as you can see in this clip:

National Geographic: Five Years On Mars
Opportunity was certainly the lucky rover ... [but] Spirit was my favorite rover, because Spirit had to work for everything she ever got in her life.
In 2018, Opportunity's luck finally ran out, when a massive dust storm rose up near her location on the rim of the 22km wide Endeavour Crater, and then spread across the entire planet, burying her in near darkness for longer than ever before. The global storm also made viewing the planet a pain during its closest approach since 2003, when I was able to show my kids the polar ice caps. This time around the youngest child got the short end of the stick, with merely a fuzzy red blob to look at.
"Opportunity likely experienced a low-power fault, a mission clock fault and an up-loss timer fault"
Like her twin, Opportunity simply froze to death. But that's not actually a bad way to go, especially with such a life of achievement behind you.

The Curiosity rover continues to roam the surface of Mars and, since it's nuclear-powered, will not suffer the problems of its solar-powered predecessors, so it could still be working in 2030. And as another hopeful sign of our unfolding future it should be noted that while the Cassini probe attracted anti-nuclear protest crowds during its launch to Saturn in 1997, there were none for Curiosity's launch to Mars in 2011.

11 comments:

RosscoWlg said...

Hi Tom,

Great story, fascinating. What ingenuity we have as a race and why the optimists will always survive! Love the personification of those little guys so far from home pushing the final frontier a little bit closer... "one small step..

Cheers Wiggo

Kimbo said...

At one stage, Spirit's front right wheel simply froze, and for the rest of its life, the rover was forced to drive backwards, dragging the wheel around like a lame animal. But in the usual paradox of discovery, one day in 2006, the stuck wheel dragged through a thick layer of dust in a crater that Spirit was crossing, revealing a bright, white layer of silica. On earth there are only two environments where silica can be formed; a hot spring, where the silica is dissolved away and deposited somewhere else, or a fumarole where acidic steam rises through cracks, dissolving other minerals and leaving mostly silica. On Earth, both environments teem with life. It was a hell of a discovery, and something the machine was not designed to find.

You read something like that and you wonder if manned space travel to Mars is worth it. The series of some 20 years ago, "From the Earth to the Moon" did a good job of explaining how only humans could have discovered the "Genesis Rock" in 1971:

https://en.wikipedia.org/wiki/Genesis_Rock

...but when you consider how robotics and AI will likely improve immensely in the next two generations, sticking to unmanned probes only is likely the best way to go. Cheaper and safer too.

Tom Hunter said...

Cheaper and safer too
Safer!!!!

Who gives a fuck about "safer" and "cheaper".

What are we: Men - or Mice? Did all those men die in vain on the field at Agincourt? Was the man who burned Joan of Arc simply wasting good matches? Should we have sent all the money for Project Apollo to LBJ's Great Society Democrat vote-catching schemes instead?

We didn't fight our way to the top of the foodchain just so we could send Robby The Robot out to explore the universe. We need to keep a close eye on them; look what happened to the Cylons when we didn't.

On the other hand, looking at that last one now...

Lord Egbut Nobacon said...

In man's quest for knowledge, and in his ignorance, when landing in the new world killed millions of people with diseases that had been nurtured in the slums of continental Europe...smallpox, TB, influenza etc. Entire communities were wiped out.

The Spanish in Sth America, the English and French in Nth America and the Pacific and the Russians in Alaska caused innumerable deaths from diseases and associated starvation.

All this was done in ignorance but now we have crossed a line knowing full well that should an accident occur we would contaminate part of a pristine planet untouched by man with nuclear fuel. Slamming into a planet at 20,000kph would certainly over come any safety measures put in place. Our arrogance knows no bounds, we see it, we want it so it's ours to do as we will.

The English match struck on the French matchbox was wasted.....as is always the case the murder of Jeanne d'Arc turned a misguided religious fanatic into a martyr and a rallying point for the fractious French.


RosscoWlg said...

Eggie sometimes you blather on about a load of crap and surely this has to be one of these occasions!

I suppose you stay indoors and wear one of those pressurised suits with its own life support system.

I thought of editing your comments into something useful but then I realised there was nothing useful they could be turned into.!

Besides I just heard that life from outer space has just landed in central France and civilisation as we know it is dying out, they are hoping to contain it to France

Kimbo said...

I thought of editing your comments into something useful but then I realised there was nothing useful they could be turned into.!

I tried and came up with this. During World War II a British diplomat was being given a tour of the White House and, given the need for the Anglo-American Alliance to function well each party was desperately keen to ensure things went smoothly. At one point the American stopped and observed some charring on the beams.

"Oh, I say, what is that?" he asked.

"Um, that was damage caused during the war of 1812".

"Oh, really?" Who were you fighting" he continued.

"Er, the British" came the reluctant reply.

"I didn't know we fought you in 1812" the diplomat responded, realising he had stumbled into a problem.

"Yes, the British burned Washington" the host explained, "but it was a long time ago". he hastily added.


"Well I never", said the Brit. "I knew we burned Joan of Arc, but George Washington too?!"

David said...

Jesusonapogostick Kimbo, you can't tell your Seppos from your Poms.

Kimbo said...

Yes, realised I had jerked it once I posted. Thanks for the correction. The Brit notices the charring and...

RosscoWlg said...

Well done Kimbob, like your joke and fair superior to anything Eggie could come up with, I'm not sure but I think he may have had a sense of humour lobotomy.

Over night the only other thing I could think of that remotely came close to Eggie being an apologist for mankind was that moron from the Labour Party who apologised for having 3 things dangling between his legs.

Cunniliffe wasnt it, who then quickly flamed out into obscurity

Adolf Fiinkensein said...

Kimbo suffered an episode of premature ajocultion earlier so I've fixed it for him. Very well done, kimbo,


I thought of editing your comments into something useful but then I realised there was nothing useful they could be turned into.!

I tried and came up with this. During World War II a British diplomat was being given a tour of the White House and, given the need for the Anglo-American Alliance to function well each party was desperately keen to ensure things went smoothly. At one point the Brit stopped and observed some charring on the beams.

"Oh, I say, what is that?" he asked.

"Um, that was damage caused during the war of 1812".

"Oh, really?" Who were you fighting" he continued.

"Er, the British" came the reluctant reply.

"I didn't know we fought you in 1812" the diplomat responded, realising he had stumbled into a problem.

"Yes, the British burned Washington" the host explained, "but it was a long time ago". he hastily added.


"Well I never", said the Brit. "I knew we burned Joan of Arc, but George Washington too?!"

Kimbo said...

Thanks, Adolf. And good to see your blog walks the line between criticising someone’s actions while not engaging in personal abuse - “ajocultion”. Very good. I wish I’d said that. To paraphrase James McNeill Whistler’s reply to Oscar Wilde, “You will, Kimbo. You will”.