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gribblefrit t1_iu2vll0 wrote

Reply to comment by djdsf in NASA spacecraft records epic ‘marsquakes’ as it prepares to die by marketrent

In the documentaries they talk about complexity. Every little gizmo, servo, control board and gadget they include is doing double or triple duty. They all have redundant systems. It all adds up to a very complex machine. They do things like tilt the panels to shake dust off, but adding the complexity to clean the panels is super hard and, in the long run, not effective. In specific cleaning solar panels with a brush could degrade the panels faster than leaving them alone, theee aren’t the reinforced shatterproof panels on your roof. They are so light weight and delicate that even a brush could damage them. This is some of the balancing act they take each time they send a rover up. How long to get a return on investment so to speak and how long before it goes to sleep.

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grim-one t1_iu3hvuu wrote

OK, OK... We'll spring for a soft brush for the delicate panels :P

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Nidungr t1_iu3o10k wrote

The problem isn't the hardness of the brush, but the dust. It is harder than any sufficiently lightweight material we could make solar panels out of.

Apparently brushing off the dust would just replace opaque dust with opaque scratches, if the panel isn't already sandblasted to hell to begin with.

Edit: The dust is electrostatically charged and clings to surfaces, so you can't easily tip/blow it off.

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WimpyRanger t1_iu3xhlo wrote

If it’s electrostatically charged, then you could induce a new charge to eject the dust, yah?

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tea-man t1_iu40jsk wrote

If I'm not mistaken, this is exactly what's beginning to happen with some of the more advanced solar power projects. Though it is very new technology requiring precise control of the electric fields in individual layers of the cells, so it's still a few years away from large scale adoption.
I suspect that any solar powered rovers that began their initial design in the past year or so may adopt this if it's proven successful.

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plzsendnewtz t1_iu41ndf wrote

Rotate the shield harmonics! Aye, Captain!

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enderjaca t1_iu46cj2 wrote

Reverse the polarity in the deflector array by negative 5! I cannae captain, it won't respond!

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alex_sz t1_iu3o6j6 wrote

A directed blow of air would do nicely I imagine

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Dsiee t1_iu3tk99 wrote

Not much air on mars, sorta why the wind isn't the best at cleaning. Also the dust is actually somewhat stuck as it has a static charge.

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dangly_bits t1_iu3smgi wrote

I would imagine the required air pump would not only use far more energy than the rover has on tap and would likely be one of the first fail points.

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colt_420 t1_iu4wbdk wrote

What if it just runs constantly like an air hockey table (Half joking half not mostly just wanted to be another random Reddit or with useless ideas here) Hi everyone :)

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Tricky_Invite8680 t1_iu3wvyr wrote

estimated 2 years, actual 4 years service life. I'm thinking maybe they can redesign the panels to have some kind of thin film cartridge that can basically renew the surface at least once. maybe even an antistatic film to boot. the land based ones must have more structure on the panels then an orbiter.

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wartornhero t1_iu407ys wrote

And weight budget. At the end of the day they can only send what they can launch and land in one go currently. So if you spend 1 kilogram on a system to clean panels that is 1 kilogram where you don't have a science instrument. It is also like 100 kilos in propellant to get that 1 kg to the surface.

So yeah it is usually better to just try other means of keeping them clear that may extend the life but may not.

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bathroomheater t1_iu43b00 wrote

So if you have the ability to tilt and move why not give it the ability to swing upside down and tap gently against the rover to knock the dust off

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enderjaca t1_iu46rys wrote

Because it's very light dust that is electrostatically attached to the panels. Tapping wouldn't do much. And as other folks have mentioned, adding more complexity to the rover means a greater chance of failure and adding more weight, which means more cost, and that you have to choose what other scientific instruments you can't include because you have a maximum weight/cost limit.

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bathroomheater t1_iu4gwki wrote

So I guess sci-fi shows have lied to me all my life and reversing polarity after randomly slapping a keyboard also won’t solve it either

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enderjaca t1_iu4l323 wrote

Anytime I get mad and slap a keyboard, I solve that problem and boom, I instantly have a different problem. Molotov cocktails work the same way.

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DeifiedExile t1_iu47ik9 wrote

You can't just knock the dust off. It's electrostatically charged, so it clings to the panels like a magnet. Additionally, those panels are significantly more delicate than what your average earth-based panel.

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Alt-One-More t1_iu4wx00 wrote

I hear this a lot but I just never understand the reasoning given. There's no way it isnt possible to clean off the panels, it's more likely funding issues in the design as well as the official "lifespan" of these probes being months not decades.

Ie they'd rather save the weight on a cleaning mechanism in order to add another scientific instrument.

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Hennue t1_iu3x6hk wrote

If the panels were as delicate as you say here, they wouldn't survive launch and EDL.

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BecomingCass t1_iu40ppr wrote

I'm pretty sure they're folded up until after landing. Nothing to get scratched on

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Rainbowdelights t1_iu3cjm5 wrote

A counter argument to this is the billions of dollars spent to land this thing and do all the rest, could completely mitigate this cause of failure through the addition of a few relatively inexpensive parts

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BirdOfSteel t1_iu3dr9a wrote

Spacecraft engineers would love nothing more than to implement all the features they will/might need if they could afford it. When your budget is determined by the government, ya take what you can get

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Throwaway_97534 t1_iu47auh wrote

But when almost every successful lander is limited by their solar panels at the end of the project, at what point do you start prioritizing them?

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BirdOfSteel t1_iu49qny wrote

I'd say you'd need to start spending more time/money on solar panels if the of one really needs it to function. So far, probes seem to be getting by fine with the current panels we put on them so there isn't too much pressure to be focusing on solar panels if they're doing the job well enough.

I think someone else also mentioned this, but adding things like wipers and whatnot would also increase weight. That's weight which could be dedicated to other important parts of the craft. Yes, you'd end up collecting more power and perhaps you'd maintain your solar cells better than before if you cleaned them, but it would take research and development on something that already works well enough.

That said, solar is something that's useful down here on the ground too, so I imagine that takes some pressure off of space agencies develop the tech from the ground up.

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Star_king12 t1_iu3ftjl wrote

Anything you send to Mars is excruciatingly expensive.

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