Having survived two years on Mars, obviously both MERs have succeeded beyond our wildest dreams... but I'm curious. What did everyone expect/hope them to go on to achieve on those heady landing days? How far did you think they'd get? What did you think would be their "best picture"? How long did you think they'd survive?

Might be interesting to compare our hopes and dreams with the reality...

Squyres is on record saying that he thought, 120 - 140...maybe 180.

Personally - I was thinking 180, twice the life of Pathfinder just about.

900....don't be so stupid.



Doug

QUOTE (Stu @ Jul 13 2006, 10:14 PM)

Having survived two years on Mars, obviously both MERs have succeeded beyond our wildest dreams... but I'm curious. What did everyone expect/hope them to go on to achieve on those heady landing days? How far did you think they'd get? What did you think would be their "best picture"? How long did you think they'd survive?
Might be interesting to compare our hopes and dreams with the reality...

I was with TPS on Spirit landing day and met with Bill Nye who's the one that got the idea to use the Sundial as a sundial. He was setting up a challenge worldwide so children around the world could make up their own sundial and could "compare" time on Earth and on Mars at the same time. Moto was "Two planets, One sun". When back to France I tried to hurry up the school teachers where my young son is studing and told them : you've got 3 months maximum to make it work!
We ALL know that spacecrafts last longer than their designated life but I was more thinking as "Soujouners", not "Voyagers"! That's my thought. Now I'd like to see dust devils in Gusev from the plain instead of uphill and I'm looking forward to the ENTIRELY NEW mission of Oppy when she'll get to Victoria.

I look back at Dan Maas animation and remember not believing it would work at all. I mean, how many other missions have cratered or flown bye? When Spirit landed, the first images were a yawn: all the interesting stuff seemed in those hills waaaay over there. But after oppy's hole-in-one I was saying yeeeehaah! it's game on. Get to work.

Never thought they would get to the hills or get out of eagle crater. Glad they did.

Stu, great thread !

Never, never expected that. We take for matter of course the flow of new images from exploratorium site every day.
This event is unique in our history. Any outcrop, rock, hill, crater taken from these rovers
NEVER been seen before from any human on our world. ! !

500 years ago C.Columbus was happy to see new coastlines in our world.
This is an another world.

Think about that.

I think we should see this from a whole new perspective.

When Spirit took a look around, I figured that, if we were very lucky, we might get all the way to the rim of Bonneville. Spend a month or so exploring the ejecta, hopefully find some lacustrine materials to make the mission worthwhile (to its "follow-the-water" goal), and die with a breathtaking view of a decent-sized crater. The hills on the horizon looked enticing, but I figured that, being several km away, there was no way in the world we'd ever actually be able to drive to them. (When they did annouince they were going to try and drive to them, I wished them luck and decided you have to have impossible goals in life... but that's what I thought it was, an impossible goal.)

When Oppy landed and spent sol after sol, week after week, puttering around that tiny little crater, I got distinctly edgy. I figured that, no matter how interesting the sediments in the walls were, we were completely ignoring the possible diversity we would find out on the plains. I was certain that there were interesting things to discover out on the plains -- and I despaired that Oppy would die before she ever got out to look at them! As much as I enjoyed the results we got from the rocks in the walls of Eagle Crater, I felt it was disastrous to spend so much time inside of it, when there were vast plains out there to explore.

I am gratified, to say the least, at how much more each of these brave girls has managed to do than what I expected. May they be like the Energizer bunny, and just keep going and going and going and going and going and going and going and going...

-the other Doug

I remember talking to my dad about Beagle 2 and saying that 1. I thought it would probably fail and 2. That if it didn't it was going to be totally upstaged by what the Americans were planning!

Even so I don't think I really had any idea of how spectacular it was really going to be, I think my mindset was infuenced too much by Pathfinder - I didn't expect the rovers to go trundling off over the horizon! After all they were only going 600m - you'd still be able to see the lander.

I remember seeing the Dan Maas animation and thinking that the terrain looked rather optimistic. I expected it to be much rockier and harder going. I was really surprized at how accurate the animation turned out to be when Spirit landed. Then came Oppy!

Just after the primary mission was over I remember a figure of 250 sols being mentioned and thinking, "no way, that's crazy".

I would have laughed at anyone crazy enough to suggest numbers like 900, (I still find it hard to beleve!) or that both rovers would drive 'miles' - Oppy driving out of the landing ellipse, Spirit not only making it to the hills but climbing to the top of one, etc.

I didn't expect to be so 'involved' - just read the press releases look at a few images now and again. I never expected to know the downlink times, and wait impatiently for the new images. Then examine them all closely - measure angles - identify features - stich - make colour from the different filters - spend 'hours' working on large pans - spend 'months' writing and refining my own image processing software. And best of all, getting to talk and share it all with so many like minded folks! (Thanks)

James

I thought 130... 150... maybe even 200 sols. As for distance, I was pulling for Spirit to circle Bonneville crater and examine her heat shield, then move on to the parachute. Of course, the direction actually taken was almost opposite. I was cautiously optimistic about Opportunity making it to Endurance once the journey was underway, and desperately hopeful about Spirit actually reaching the hills and maybe, just maybe, crawling up a ways.

Now both rovers are showing clear signs of age and breakdown and I'm thinking 300, 400, maybe 500 more sols. More now than I gave them at the start.

I remember clearly how after Bonneville Spirit's planners decided to move in the direction of the Columbia hills - they were cautious enough to not claim that the hills were an actual destination! It did seem like a very optimistic goal at the time, but I have to say that for me this was based in part on how the hills looked in the images from the landing site. They looked really far away. I've learnt again and again since then to always mentally add a disclaimer: "objects in these images are closer and smaller than they appear".

Still, odometers don't lie, and I certainly never imagined on landing that the rovers would do 7 or 8 or more km, and indeed pass over the horizons that were visible upon landing!

It's also so cool that for both rovers we've always had another intriguing destination ahead. This I did not expect. What if Spirit had landed nowhere near any hills, or Oppy far from any sizable craters? This to me has really made the missions so compelling to watch (take part in??!). Absolutely fundamental to this has been the work of Tesheiner, Alan, et al on mapping. It took jpl too long to catch on how important up to date mapping was to make the public feel like they're taking part in the missions.

I was expecting nothing, from some spiritual training, and also from experience, as I follow the space exploration program since its beginning. There was so much dreadful failures, along with some outstanding long lasting success (Voyagers)...

However my technician background was telling me that these frail looking machines were not designed to live long in a rugged terrain. With their stated goal, three months, 600 metres... and Spirit's software problems just after some metres. I would have be really surprised if I had a vision of the future at time of landing!!

Now Spirit seems definitively unable to move for long distances, but she could still bring some surprises. If I was the mission planner I would try to send her toward the smaller hills to the south of Columbia hills. They look strange and different. The future of Oppy is still unpredictable, and I shall not try to guess when she will encounter a crippling failure. Tomorrow, one year, ten years... a motor could stall, batteries are cycling... So I receive each passing sol as some divine grace. Exploring Victoria may take months, and Oppy could not climb back. But if she does, the wild bet would be to send her toward the big crater in the south-east... the only place which is not covered with evaporites and which could bring a glimpse of the underlying soil.

I can't speak for the rest of the gang, but I share your perspective as well. On Pathfinder, I remember seeing the twin "peaks" off in the distance to the west. When Tim Parker did the triangulation, I was surprised at how close they turned out to be and a bit taken aback when I realized we could have seen a person standing on them. I knew they were far out of reach of little Sojourner, but I had hoped that we would have been able to drive her up a mild slope to the North and possibly peer over. I resolved then that we really needed a rover that was free of its lander and able to trundle off away from our landing spot. Prior to MPF/Sojourner the thought that it might really be possible to build a "roving" spacecraft was just a tad too "out there" to be real. A few of us in late '97 considered a design for '01 where the inner box of the MPF lander would stand up and drive off. Mark Adler came into my office in April of '00 with the same idea and the rest is history. Being stuck in one spot is frustrating (unless your lander is a backhoe like Phoenix).

I agree with James, Dan Maas' video seemed too unreal to be believable. Despite the rock abundance estimates from Matt Golombek, I fullly expected a site (at Gusev) that was closer to VL-2 and MPF than the relatively drive-able place it turned out to be. I was thrilled that we actually made the decision to head to Bonneville, but I was really (pleasantly) surprised when the science team decided to head to the hills the moment they discovered that there where no outcrops in Bonneville. When we finally got there I realized that Dan's video was the tip of the iceberg so to speak. Dan is a visionary. (I gave Dan a tour of the sandbox testbed rover last year - it was the first time he had seen a rover with his own eyes. He is amazing.)

Back in March '04, in the 5th floor science room a huge MOC strip of Eagle down to Victoria was laid out on a line of tables. Endurance was still the target, but Tim gave me a serious look and pointed to Victoria as our ultimate destination. I laughed but secretly hoped that he was right. We weren't even sure if those little "snake-like" structures between Eagle and Endurance were traversable. What if they were hollow and the rover fell in? 6 km looked like a long walk.

Before landing I guessed that the longest these two would have lived was about 4-5 months and about a km or so. Certainly not 10x both life and distance. No one did (at least no one admitted it to me). The team is still rather skeptical.

-Rob Manning

***********
Comments made here are the express opinion of the author and do not represent the views of JPL, Caltech nor NASA.

After the landings and the slow initial journeys, I thought they would make it to winter which was 200 - 250 sols. Then after they made it thru winter and got dust devil dust-off, I no longer had any expectations on how long they would keep going other than they would keep going and going. Now, my hope is that they both make it to when Phoenix lands. Having 3 operating spacecraft on Mars is a cheery thought (assuming Phoenix makes it, too).

From the little data we got from MPF and Sojourner, we estimated something like a quarter of a percent per sol loss on the solar arrays from dust accumulation or 25% or so after 90 sols. There was some test data that suggested it could be better - or worse. We all thought that the dust would be "sticky" and no amount of wind could remove it. (There were afternnon dust devils that passed on top of the Pathfinder lander that did not have much affect on the accumulated dust on the arrays. why? height above ground?)

Apparently, design margin, the wind and milder temperture swings has made all the difference.

-Rob

I remember when the rovers landed and my idea was "Pathfinder/Sojourner on steroids" but nothing else.
A longer mission (90 sols), longer driving capabilities, and that was the scenario; I didn't expect (by that time) they could surpass the nominal mission by more then 50%.
When they planned to go toward the hills I thought it would be very nice to end the mission with pancam images resolving details on the hills, that's all.

I think there are two things I could never imagine before this mission:
1) It's longevity, therefore the big number of sites that could be visited.
2) The almost immediate access to the images and the ability to work with them, giving the feeling of being "part of the mission".

Hi all!

I've been a lurker for a good while now but this is my first post, since I can't really speak authoritatively on the more serious topics.

I had high hopes at landing, at least 100 sols maybe even 150-200 and at least one rover to rove over 1km. I had much higer hopes for Gusev (I really like the PP presentation by Nathalie Cabrol advocating for it). Meridiani always felt like such a sure thing, only really unique site identified by TES and so flat. I was certainly surprised by the results, though I still have a soft spot for Spirit.

Eluchil

Great replies and memories guys, thanks

As for me, well, being the Mars nut that I am I was almost unbearably excited when it came to landing day(s), having sat here at my PC watching the launches of both MERs on tiny Real Player boxes all those months previously. The night before Spirit landed I was actually a guest - the token "amateur astronomer and space enthusiast" panel member! - on a BBC Radio 5 phone in show, which linked people in Carlisle (me), London (I can't remember which author/scientists it was now... I think it was Ian Ridpath... yes, pretty sure it was...) and a MER team member over at JPL (definitely can't remember who that was now!) to discuss the next day's big events. I remember sitting in the studio, on my own, at midnight (cos of the time difference), with the big clunky headphones on thinking wow... Spirit's closing in on Mars right now, as I sit here...

( Sadly, the phone-in, which was supposed to be a serious discussion about what discoveries the rovers might make in the DAYS ahead turned into a pathetic "Couldn't the money be spent on better things?" tirade by irate callers, thanks to the go-for-the-easy-and-cheap-shot attitude of the presenter, Richard Bacon (UK board members will be nodding, thinking "Ah, no surprise there...") and Ian and I both got very frustrated with the whole thing, as the science and discovery aspects were swept aside by Angry From Milton Keynes rants about how the money should have been spent on things "down here"... the same people I'm sure who don't think twice about renting DVDs, buying takeaways or... well, don't get me started... and I went home very annoyed. But it was so late when I got back that the landing itself was just hours away, so I stayed up, bleary-eyed, and gulped down huge amounts of coffee before the coverage started...

... and as the first pictures came in I really thought that we were going to see "more of the same", thatw e'd have a couple of months, maybe six, of pictures of rocks and dunes, like a mobile Viking. The Columbias seemed like they were on the end of a martian Oregon Trail, so far out of reach they weren't even worth thinking about never mind aiming for... Then Oppy landed, that amazing cosmic hole in one in Eagle Crater, and I just thought "Well, that's it, better get used to this scenery, gonna be here a while..."

But as time passed and the rovers went on their way I began to think that yeah, this was going to be different after all. This was discovery, a trek, a genuine adventure. New pictures every day, new discoveries, new speculations... I've said it before, I know, but it really began to feel like walking alongside Lewis and Clark, seeing new landscapes and landmarks with every sunrise...

I hoped for maybe 6 months of life on Mars from one rover, with the other meeting some kind of accident or technical failure, I certainly never expected both to survive. I hoped that one of the rovers would manage to snap one image showing Earth in the sky. Yep, did that. I hoped that one of the rovers would find a meteorite on Mars, being a meteorite collector myself. Yep, did that too.

And it's just been one met challenge after another since then. I remember when Spirit stood at the foot of the Columbias, staring up at the summit of Husband, half a light year above the Gusev plain, and thinking "No way...!" But she did it.

What I didn't expect, and others have touched on this, is just how personally involved I would feel in these missions. I thought NASA might release a few pictures each week - yet every day there are dozens of new images, higher resolution than I dared imagine. I thought I'd maybe check for new pictures a couple of times a week - but I drool over new images several times a day, given the chance; I thought there'd be a couple of Forums where people would discuss NASA images - I never dreamed there'd be a place like this where people would take raw images and turn them into literally stunning works of art, unique and beautiful. I thought I'd get blase about the rovers, and not think of them as anything more than mere machines, but I find myself actually worrying about them, and hating the idea of Spirit dragging that wheel behind her in a race against time to find a slope to survive the winter on. It's crazy! They're just machines! But they're not, they're real to us, and they're our eyes on and ambassadors to this fascinating, brutal, beautiful world called Mars, and god, I'm going to miss them when they're gone.

The biggest and best surprise has been being able to share this adventure with other people, the people reading this; when I sat there on that sleep-deprived morning, watching Spirit's first images appear on my screen, smiling like an idiot at the sight of the airbags crumpled around the lander, I thought "Well, here we go, six months of lonely screen staring, nobody else 'getting it'..."

You all 'get it', and I'm not alone when I look out at this new Mars. And that's wonderful.

Gusev was quite a disappointment to me at first glance, then the rover stopped working for a while.
And like many I wondered if we even would get much images or science from this rover at all.
But when it eventually started to go the first drives were slow and it was obvious that the drivers actually
were learning the skill of driving at Mars on the go.
With all this in mind Bonneville crater wasnt even one obvious goal, but a distant hope, the hills were just a pipedream in those early days. And with the problems Spirit suffered I didnt expect it to last the mission time of 90 days.

Opportunity was another story, I got as enthusiastic as anyone with what was found in Eagle crater, but soon
wanted to move on to Endurance and the rover couldnt move fast enough for my taste. I could see the mission days ticking away and feared the rover would have any kind of mishap. I knew the potential of the rocky wall we could see from the distance on the side of Endurance. I hoped that it would provide a peek back in time to see what earlier geology might have been like. So early on I both wished and almost prayed that Opportunity would last longer than expected and be allowed a mission extension to be able to explore the crater in detail - as it eventually also did.

Edit: I have to agree with jamescanvin. I didnt expect to get captivated by a mission like this either.
And Im still trying to find the reasons for me with my background to be caught by the two rovers in this way, so im still trying to do psychoanalysing on myself about this
But the -almost- daily images changed have changed the way I use the Internet completely, and that I spend several hours a day at this are something I find unbelievable even when writing this very sentence.
Buyt the fact remains the planet always have had such a special meaning to me that as a teenager I did daydream about exploring Mars when walking on high elevation ground here where you dont see much more than soft sloping mountains, gravel and lichens groving directly on the rocks. So its not suprising, and im happy to have found a place where theres others with the same interest - thank you all!

Whouaaa! I didn't realize THE Rob Manning was in the Forum!
Since I saw you for real the day after Spirit landing day at the TPS "Creazy about Mars", you're my hero Rob. You're not only a TOP engineer, you're what we all need : a wonderfull communicator. And to stay on Stu's topic, one of my interogations after Oppy's landing was : "OK, Rob is 3 for 3 now, will he continue to give us another or more clean and successfull EDL?" I didn't expect to be able to ask you the question over the Internet ...and the UMSF forrum.
Climber

Do you remember problems of Spirit several days form landing? I thought 'this is the end'. Yes, so pessimistic I was .
I dreamed of Spirit on a top of Columbia hills. I realized, that their distance is feasible for Spirit to travel. But again I was pessimistic and treated it only as a hope.

Since then it's been one pleasing surprise .

The low point was Pete saying
"There is no one fault that explains all the observables" and looking like a head teacher telling off the class when he said it. Scared the hell out of me that did.

Doug

He also said at one point that, if recovered, Spirit will never get back to 100% capabilities! He should have said 1000% instead

I expected fossiles, abysses, crawling creatures, and even that the rovers would last long...well...not that long...but at least in that mad supposition I got right...

Hi Guys

I agree with just about everything Stu said with one exception. I do get personally involved in these missions and tell people at work things like, 'one of my landers is going to arrive today!' because they are all mine! Mine! I tell you, but I'm happy to share them with everyone at UMSF.
While I've got the basic geology, it's good to have the experts here and the photo wizards too.
To summarize, I expected little and got lots, and am hoping for more ("aliens, Listy, aliens."(Red Dwarf))
Roy F
aka Reckless

Actually I do the same thing. When refering to the rovers I use 'we' as in 'us and them' - quite odd.

Doug

A little before the MER launches, KSC was holding a Nasa direct question and answer session streamed on the net. I sent two questions to them, one about the rover radios (this one got asked, which meant that I received a MER patch, sticker and pin). The other question was essentially "Is there any possibility that a rover might survive the Martian winter?". Basically I was looking for any bottom line survivability limits for the rovers, like the batteries were for Pathfinder. Unfortunately they didn't include this question in the session, maybe they thought it too far fetched :-).

But surviving two martian winters. I couldn't thought of that.

I remember being upset and depressed when I saw the nominal mission duration... 90 days. How could they send rovers to Mars and only design them to last 90 days!? I thought a short mission was inevitable due to dust buildup. Needless to say, my spirits have lifted since then.

I was expecting a lot less than what we've gotten. My sights were set on a nominal 90-day mission, rather like an enhanced Pathfinder/Sojourner mission. Then I lived a stop-at-a-time: first Eagle, then Endurance, then the Heatshield, and thence the journey south. Same thing with Spirit, although the initial part of the mission was travelling from the landing site to the Columbia Hills, with a side trip to Bonneville.

They will go as they go. And after they are gone, we'll still be working with their legacy: the data.

--Bill

I remember watching the landings live, and I'd hoped and expected that they'd do better than the Pathfinder lander did. I was discouraged seeing Spirit struggle with its software issues, but when they fixed it and when Oppy got going in the crater, I was just happy seeing day after day of success, hoping there'd be more days of great pics from Mars. I didn't expect THIS though In fact I remember one of the project managers saying the rovers would no longer be operational when the Mars Reconnaissance Orbiter was scheduled to fly in 2005, during a televised press conference. Whoever said that's gotta be eating some delicious crow.

Initially I expected perhaps a 120 day mission. I thought mechanical failures, dust buildup, or getting stuck in the dunes (because the wheels are too small!) would've ended both missions earlier. I am very pleased we have made it this far, both rovers have far exceeded what I had thought possible.

I am hopeful we might even get another two earth years out of the rovers.

Hey Rob,
Any plans for an Imax documentary for MSL a la Roving Mars? I absolutely loved seeing those high-res pictures of the rover on that giant screen, and listening to the team's trials and tribulations through the project.

What about Nova and MER? I bought both of their MER videos, and would love to see a third followup with the "story until now", perhaps "A Thousand Martian Sunsets" would be a good working title.

I remember following Nozomi, Mars Express, Beagle 2, Spirit and Opportunity to Mars in 2003. I tried to guess odds beforehand of each one succeeding so as not to be too disappointed. Worked out pretty much exactly the same as my predictions: the ones I thought had a less than 50% chance of success failed, the others succeeded.

The Spirit landing I found hugely exciting but also very slightly anti-climatic. I was hoping for dramatically different terrain: it looked just like the old sites, but with fewer rocks.

The first images of the Opportunity site shocked me. In a good way

I loved what Stu wrote about this community. I too was glued to my little RealPlayer feed during the Spirit landing, very excited but also a bit lonely- even most of my professional colleagues didn't find this mission quite as riveting as I did. So discovering this group of fellow-fanatics, who are as thrilled as I am by every nuance of the landscape as we (yes, definitely "we") keep on rolling forward, has been one of the best surprises of the last 900 sols. Thanks as always are due to Jim Bell and Steve and their generosity with the images, which has made this level of vicarious involvment possible.

Like everyone else I'm amazed by the longevity of the rovers, but I'm also amazed how the extreme slow-motion pace continues to hold my attention. Lewis and Clark made it to the Pacific and back in the time the rovers have taken to cover their handful of miles, but still I can't wait to log on every morning and see that incremental bit of terrain revealed by the previous sol's few steps forward. It's just a bunch of rocks and sand, but it's on another freakin' planet! I'm glad you all "get" it too.

I remember all but laughing at someone, either on this forum or a similar one, who was saying around Sol 300 that he thought at least one rover would make it to Sol 1000. I'm not laughing any more....

Back in early 2005, Steve Squyres went on informal record saying that
he thought Spirit would reach 800-900 sols and Opportunity would go on
"indefinitely".

I wonder if at least one of them will still be around when MSL lands?

Or dare I say even ExoMars?

I remember seeing this image and thinking Wow!. I didn't realize how small those rocks were. I was thinking they were much bigger

After the landing, it was my extravagent hope that the mission would make it to Bonneville with Spirit and Endurance (for a quick and dirty look) with Oppy. I had faint hopes that one of the rovers might be able to hit a second major target.

I thought there was a minor chance that one of the rovers would be be able to survive as a stationary outpost through the winter...like Spirit is now (her, I suspect, final resting place).

>I remember seeing this image and thinking Wow!

I remember those first images. Thinking "we're in a crater. that's like a roadcut!" and "rocks. stratified. sedimentary!".

I faithfully followed our rovers on my own for about the first year, I hadn't found discussion groups. I found one, but I came to realize that it was a bit odd in that it seemed to be an institution run by the inmates. Eventually I found UMSF, and nirvana...

--Bill

Oppy's landing place was really a shock to me... it was so outlandish! Another shock was some days later, when I discovered the vision of gypsum vugs... For some hours I did not understood anything, thinking to fossils and the like, until I realized it was gypsum vugs. This alone was already a great discovery.

High moments too were when healing Spirit problems and also when getting out of Purgatory. Being in electronics, I was not completely astonished by repairing a software only through an intermitent radio link, but Oppy seemed so hopelessly stuck in sand... I was sending messages for a solution to the MER site. (They seldom reply, but I think they read all). It is in this way that I found UMSF...




Yes I understand that THIS was disapointing!! Discovering a new world, and still being stuck into such petty concerns... The fault of the presenter, but the public, knowing him, knew what to expect and only the ones interested into stupid ranting came, I guess. Unless the questions were "selected" to be a "realistic sample" of the public... disapointing for us too, for the ones who posed interesting questions.

Just to add one more memory.

I was in Madagascar doing voluntary work in April - July '04 and was totally out of touch with the outside world. I remember checking into this forum from an airport terminal in Mauritius on my way home expecting that at least one rover would be no more (it was getting on for twice the mission liftime after all!). I was so thrilled when I read that not only were they both still alive but that Spirit had made it to the hills and Oppy was down inside Endurance!

James

P.S. I use "we" all the time as well.

NASA just posted a news item on the upcoming Viking 1 landing 30th anniversary,
and it says that the Vikings were also guaranteed to work for only 90 days. Must
be a standard spacecraft warranty contract for all US Mars landers.

The Viking 1 lander outlasted all the other components of the Viking mission,
reporting back to Earth until 1982. Had there not been a glitch, it was predicted
to keep returning images and weather data until 1994. NASM had even set up a
station to display images from the lander.

First of all, I was real glad launch went fine for Spirit. The days before landing I couldn't get it out of my head..a mixed feeling of looking forward to see, maybe disaster. EDL is very exciting I figured, we're about to HAVE that, we'll see what else..I decided to switch to optimistic mode and remember being rather soft-eyed watching the team members joy and first images from the surface as Spirit finally made it bouncing over the plains.

This is what I had been waiting for since Pathfinder, and it only got better.

When Opportunity landed I went, Oh cr**, we got two of them !!

Well -it's been awesome so far, I expected the rovers to die much sooner, they didn't. After 180 sols I stopped worrying and frankly, there was a lot of data already accessible -back to work now..

Great thread

Nico

Another interesting result is that, despites the fact the two rovers are US, the results are, in a way, an international joy. This is especially visible on UMSF, where there are people of all the countries where there is freedom of Internet.

International, indeed. Remember the Frappr site: http://www.frappr.com/unmannedspaceflight .

--Bill

Which was started by a Brit, has a Belgian as his #2

Dou

Hi Climber,

Thanks for the kind words. Ironically being a "communicator" is essential to being a good systems engineer (“jack of all trades” so to speak). It comes in handy when I need to get engineers and scientists from disparate disciplines to talk to each other.

I am lucky to be 3 for 3 on EDL, but I have to say that building these beasties took a lot out of my family and me. Working in the Mars program office, I am able to take a break from the intense stress (and yes, fun) of flight projects. I am not directly working on MSL but I spend a lot of time with my friends on MSL technical issues as well as on MRO and Phoenix. Building Mars missions is more than a bit addicting though - probably for the same reasons that you all are excited about it.


Hi Arccos,

Yes I remember the Spirit "Sol 18" anomaly (that is what we all call it now). It was very depressing. We were so jazzed about Spirit doing so well (we were just about to RAT Adirondack – I remember the “GO” command being sent and the Honeybee gang almost ready to explode with excitement. And to have it suddenly stop talking to us was just creepy. It reminded me of the times that MPF disappeared (actually more than once). We have a little display that allows us to see the “carrier signal” before the data starts to flow. This typically shows up within a second or two of when we would expect it. When it does not show up after about 10 seconds, you can pretty much be assured that it is NOT going to show up and that something bad has happened. Makes for instant knots in your stomach.

Our project manager’s comments about Spirit’s probable demise were based on our collective feeling that we most likely had a hardware (memory) failure. It is better to be clear with the world that we were pessimistic than to paint unnecessarily rose colored picture. Ironically it was during that press conference that we got our first tiny bit of data that started us to think that maybe the hardware was fine and that it was a memory data corruption problem of some sort. We raced to tell him, but we were too late.

Aquo,

The Mars Pathfinder lander (which among other things provided the communication path to and from Earth for Sojourner) used a very old primary battery technology – silver-zinc (we did not have many choices). This technology only allowed us to reliably re-charge the battery 40 or so times (I think we got something like 60 charge cycles out of it). It was a ticking time bomb that limited the life of MPF. Once it died, we had to resort to solar arrays in the day time and nothing at night. It just got too cold for the electronics. On MER we used the same Li Ion battery technology you use on your cell phone. These are much better at charging up (if done properly). The dust accumulations on the solar arrays (and motor brush wear) were our only “life limiters”. But still – we are surprised at the duration and distances traveled.

Centsworth –

90 Sols was all we could guarantee assuming the dust accumulation rate on the solar arrays we saw on MPF in ’97. We actually extended the size of the solar arrays (the additional “flip out wings”). The “wild card” was the need for heaters in the early morning hours. If the temps got down below -90 or lower the heater usage would go way up. Our design had a nasty “smoke stack” where a lot of our precious heat would leak up the Pancam / Mini-TES mast periscope at night. We had a hard time really understanding what the actual temperatures were going to be. We had to be conservative to meet the 90 Sol requirement, but we never knew in advance how conservative we were (or weren’t).

Hendric-

I do not know of any plans for another IMAX or NOVA documentary for MSL. These tend to show up near the end as the project nears launch (after many of the cool tests have already taken place).

"A Thousand Martian Sunsets" WOULD be a good working title! These sorts of decisions are up to others who have the interest and money to do it. The NOVA producer really went out on a limb – can you imagine all that investment in filming while watching the trials and tribulations (and threats of cancellation)? If MER did not make it to launch then his show would not have aired and he would have wasted about 2 years of film making. I was impressed.

Richard- I totally agree with your “international joy” comment. In particular the Mars science community is absolutely international. Just look at the instruments on MSL. It is fun to be part of an international experience.

-Rob Manning

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Comments made here are the express opinion of the author and do not represent the views of JPL, Caltech nor NASA.

Isn't temperature cycling on external hardware (like the Pancams and Navcams) still an issue? As far as I know, Pancam has no survival heater, only a warmup heater for nighttime operations. Surviving 2000 sols' worth of deep temperature cycles is proving to be a little bit of a challenge for our MSL instruments. (Up on the mast we can't get any of that nice RTG waste heat to keep us warm at night.) Maybe the margins for the MER cameras were really large, or maybe our solder joint lifetime models are just way too conservative.

Hi Mike,

Maybe I should have said "dust accumulations on the solar arrays (and motor brush wear) were our PRIMARY “life limiters”." You are right of course. The diurnal temperature cycles also limit life on bonds and solder joints, but in the MER design phase, we figured that dust and brush wear would most likely beat out Arrhenius-like thermal cycling failures (although we had to prove it). At this point I would have to agree that thermal cycling is a looming threat to the rovers.

And yes there are no survival hearter on the Pancam and Navcams. However MER's survival heaters were not intended to help the thermal cycling problem, they were intended to prevent the instrument temperature from going below the flight allowable temperature (or worse, going below the qual temp). They were meant to keep the hardware from breaking under extreme low temperature conditions. The energy needed to run heaters to reduce cycles would likely be a lot higher than for surival heaters.

The issue of thermal cycling is critical for any Mars lander that has to be designed to last on the Mars surface. The hard part is proving that it will last. It is hard enough to "prove" that the design works and survives for 90 sols (with margin), let alone a Mars year. It is a tough one.

Good luck!

-Rob

I just noticed that Spirit hit 900 Sols last night. I know of no one on MER who believed in 10x the design life. No way. I guess we will have to begin to imagine that they could keep on going for some time.

very cool.
Thank to you all for your support and interest in the excitement of Mars Exploration.


-Rob Manning
Ex-MER FS system engineering manager

Just thinking - 83ish Sols for Pathfinder, with Sojourner still going strong could be considered nearly a 12x 'shelf-life exceed'. I desperately hope that MRO might catch some tiny hint of where Sojourner is compared to it's last know location back in 1997.

Thinking of the MSL mast thermal issues - has there been any thought of a solar absorber ( as there was with Beagle 2 ) designed to just warm up during the day and dump it out over night...or is the risk then that during heavy useage, the entire lot ( and there's quite a bit of kit up there I guess ) would get too warm.

Doug

Hi Rob,

Congratulations !!

to you and the whole team and please see that I did make note of Spirit hitting 900 Sols earlier today in the Spirit thread listed below. 10 x design lifetime is such a fantastic milestone that I felt it deserved a special mention.

http://www.unmannedspaceflight.com/index.php?showtopic=2961

ken