Dust storm on Mars is threatening the Opportunity rover.

[Canopus]

6 minutes ago, Shpaget said:

This existing approach stinks of planned obsolescence.

Oh come on you can't be serious..

[Shpaget]

Sure I can.

A rover does just good enoug job to justify a next mission, which starts another multi-year cycle of R&D and mission planning, but not more.

Planned obsolescence is omnipresent in everyday life. Why would you assume it's nonexistant in aerospace? Those people and companies too want to have a job after they finish that one assignment. Why would they build something to last beyond mission parameters if just meeting them is enough?

[Tullius]

7 hours ago, Diche Bach said:

So, to you guys who are buffs or experts on this stuff: why did they send rovers to Mars without a radioisotope generator? That tech is like what . . . 45 year old? Was it just cost?

It seems it was always pretty obvious Mars is a dusty place, and thus solar power was problematic

Curiosity's RTG produces only about 100-125 W, amounting to about 3000 Wh per sol (Martian day). The solar panels on the MER rovers are usually capable of producing 300 to 900 Wh per sol. Considering the size difference, the solar panels on the MER are actually not that bad in comparison to Curiosity.

Edited June 14, 2018 by Tullius

[kerbiloid]

1 hour ago, Streetwind said:

Already answered two posts above yours:

It was designed to operate for 90 days. Long-term maintenance gear was considered pointless.

This explains why not RTG or another expensive equipment. Not 20 USD wipers + tax + delivery.

[Streetwind]

That's like saying the box that a microwave meal comes in should be made resealable, because resealable boxes are ubiquituous and cheap. Nevermind that there is no point resealing a dirty, empty box. Regardless of the cost involved, adding wipers to a rover designed to be discarded before the panels even have a chance to get dirty is equally pointless*.

Besides, you have no idea of the engineering effort involved. A "20 USD wiper" would be broken before arrival on Mars, because rubber becomes unusable in extremely low temperatures (and who knows what several months worth of hard vacuum does to it). Their cheap electric servos are not sealed against regolith dust, and would fail within weeks on the surface. Wipers also cut into the mass budget the rover can work with; even 250 grams is no trivial amount on a vehicle that only carries a few kilograms of science payload. Then you're going to have to budget tens of thousands of dollars (or more) for development time, ground tests, reliability assessments, design reviews, sterilization... the list goes on.

It's always easy to play the armchair engineer with 20/20 hindsight. Real life is often far more complicated.

 

 

*(Whether it makes sense to design your rover that way is an entirely different discussion.)

[Ho Lam Kerman]

Hang in there Oppy!

[YNM]

3 hours ago, Shpaget said:

Somehow I believe that such expensive projects should be built with as many safeguards as possible for indefinite extension of operation.

So something that's launched now should have like, petabytes of bandwith ?

Sure, but 10 years after we'd want exabytes of bandwith.

 

It's not about "planned obsolesence", it's because we've moved forward.

Keeping a relic working takes an insane amount of effort. Look how the UK keeps their victorian railway relic up to a western modern standards - fascinating, sure, but very expensive. You don't have these capabilities for probes (at least yet) : the only space probes with provisions for upgrade is the HST, and see where it takes us.

 

It's not our fault that we always want more.

[VaPaL]

3 hours ago, Shpaget said:

Which begs the question, why is such complex and expensive hardware expected to last only a few months, while the total mission time from concept and design to data analysis takes many years. I think that both Spirit and Opportunity showed us that there is plenty of science to be done well past the designed lifetime.

Somehow I believe that such expensive projects should be built with as many safeguards as possible for indefinite extension of operation.

This existing approach stinks of planned obsolescence.

Every space hardware seems to live longer than expected and I think some factors are involved. Uncertainty factor cause the safety factor to be higher, there are a handfull of rovers in Mars, that's not enough to know exactly how every factor impacts the life of the hardware, let alone the difference in regions they are. A little of overengineering, is better to have something a little less capable that does the job than one that brakes on arrival, so even if the conditions are very well known, they will go a over the top to be sure.

So in the end will make a rover that is expected to live some months and you make your mission duration as so. If it endures more, you extend your mission. There is no point in making a 10 year mission if your hardware is not expected to survive that long. Also, if this was planned obsolescence, they wouldn't extend the mission for so long.

6 hours ago, kerbiloid said:

Why does this fully mechanised rover not have a simple windshield wiper.

This could be due to the risks of scratching the solar panel. The martian dust in the region could had been more abrasive than expected, over the time the scratches would build up and reduce the capacity of the panels. A safer solution would be a dust blower, but that would also be heavier. And after all, it was shown that cleaning the dust is not needed

[Diche Bach]

I don't think spacecraft or rover production volumes are sufficient to "host" a true "planned obsolescence" design and marketing philosophy. Rather, as others have stated in more indirect terms: these projects are about designing to meet specifications and reduce unintended bad outcomes. In order for planned obsolescence to be an advantageous strategy there needs to be a high enough volume that future needs are highly probable.

[tater]

This was not planned obsolescence. They were planned to last 90 days, it's been rather longer than 90 days since they landed.

 

[wumpus]

29 minutes ago, tater said:

This was not planned obsolescence. They were planned to last 90 days, it's been rather longer than 90 days since they landed.

I'd have to assume that a 90 day dust cleaner would involve a compressed gas used to remove dust.  No way that there would still be any available by now.  Maybe some future rover will compress the martian atmosphere to produce a dust cleaner, but I'd hate to think how much that would deplete already dangerously low batteries.  Any other ideas?  Orbital (double orbital?) feather duster?  presumably a single light feather with minimal stress on the duster (although it would have to move fast enough so it doesn't leave dust on the panel)?

[magnemoe]

1 hour ago, wumpus said:

I'd have to assume that a 90 day dust cleaner would involve a compressed gas used to remove dust.  No way that there would still be any available by now.  Maybe some future rover will compress the martian atmosphere to produce a dust cleaner, but I'd hate to think how much that would deplete already dangerously low batteries.  Any other ideas?  Orbital (double orbital?) feather duster?  presumably a single light feather with minimal stress on the duster (although it would have to move fast enough so it doesn't leave dust on the panel)?

You would compress air before the storm and use it to clean afterward, but yes this would increase mass and it has worked so far without it. 

[cubinator]

Picture from Gale crater one week ago, featured on APOD today:

[Scotius]

It looks like pea soup Thin atmosphere, my gluteus maximus. It still carries some nasty weather patterns. Global sandstorm, geez...

[Gargamel]

On 6/14/2018 at 3:13 AM, Shpaget said:

Which begs the question, why is such complex and expensive hardware expected to last only a few months, while the total mission time from concept and design to data analysis takes many years. I think that both Spirit and Opportunity showed us that there is plenty of science to be done well past the designed lifetime.

Somehow I believe that such expensive projects should be built with as many safeguards as possible for indefinite extension of operation.

This existing approach stinks of planned obsolescence.

They weren't designed to last 90 days, they were guaranteed for 90 days.   

If they were designed for 90 days, that would mean under a normal distribution, the mean mission length would be 90 days.  Half of the time, the rover would fail before 90 days, the other half after 90 days.  But since they were guaranteed for 90 days, then something like 99.9% of the time, the mission would fail only after 90 days.  Of course they couldn't say 100%, krakens happen. But given a normal distribution, if the guarantee was 90 days, the mean expected mission length would be much much loner than that. 

Because they were guaranteeing 90 days, the mission would be funded for those 90 days.  They would also easily have funding and plans in place for the next 90 and so on, as the fail rate would slowly increase. 

So this isn't engineered obsolescence, it's careful and honest planning.

 

 

Edited June 17, 2018 by Gargamel

[cubinator]

23 hours ago, Scotius said:

It looks like pea soup Thin atmosphere, my gluteus maximus. It still carries some nasty weather patterns. Global sandstorm, geez...

It's thin enough to cause problems, and thick enough to cause problems. 

[NSEP]

Picture taken from Navcam Right B. Looks pretty dusty.

I love the fact that NASA releases raw images on the internet.

Last image taken by Opportunity:

Edited June 17, 2018 by NSEP

[FleshJeb]

1 hour ago, NSEP said:

Last image taken by Opportunity:

Is the white streak an artifact, a meteorite, or a moon?

[ProtoJeb21]

3 hours ago, FleshJeb said:

Is the white streak an artifact, a meteorite, or a moon?

Looks like an artifact or glitch to me. 

[Kerwood Floyd]

"That's no moon!"

[kerbiloid]

Spoiler

8 hours ago, NSEP said:

It's full of stars!

 

[Gargamel]

Given the amount of dust in the air, I'd guess those aren't stars....

[kerbiloid]

Spoiler

3 hours ago, Gargamel said:

Given the amount of dust in the air, I'd guess those aren't stars....

Famous last words from Odyssey 2001.

Spoiler

 

 

[Wjolcz]

I will be pleasantly surprised if it comes out of that one still working. I don't think it will though.

[NSEP]

Analyzing pictures for fun is fun. I like having a little but of insight on what is going on in the world on another world.

This one was taken yesterday by Curiosity.

 

For comparison, this one was taken 20 'sols' earlier

The signal clearly has a little bit of difficulty punching through the dust storm.