Hacker News Reader

Comment by jonah | Hacker News Reader

Maybe on the next rover, they can include a brush or blower on the arm so they can dust off the solar panels occasionally.

View on HN

Eventually we'll have equipment on Mars that we want to function for a long duration, and we'll need to solve that problem, but for InSight (and others) death by dust was by design.

It costs money to operate these probes with a whole staff here on earth monitoring, commanding and analyzing the data that we receive. After some time you get diminishing returns on how much you can learn from the same probe, and would be better off paying these people to work on a new probe (improved using what you have learned) or even an identical probe, deployed elsewhere on the planet.

When these missions are designed that is taken into consideration to determine the desired lifespan of the mission, and the probe is designed to that lifespan (with some margin). Spending money (or worse mass) to make a component survive well beyond that lifespan would be a waste, and could cut into the (fiscal or mass) budget resulting in tradeoffs that make the probe less capable during the lifespan it has.

Insight was designed to operate for at least two years with margin. It has hit the limits of that margin after four years and it's time to shut it down.

Well said. Never thought about it from this perspective.

It's all true, but times are changing. Soon it will be cheaper, as lift cost drops, to just send a thousand cheap, heavier probes towards mars... than one super engineered probe.

But with a thousand probes you still might not care about dusting the panels off. It all depends on how long you need the probes to last. Mass savings will still be important, in the same way material costs become more important when mass-producing something than when making a one-off.

The sweeper arm idea is better for panels on Earth due to humidity: https://news.mit.edu/2022/solar-panels-dust-magnets-0311 Electrostatic based solutions using a layer called an electrodynamic screen that was introduced in the early 1970s using interdigitated electrodes has potential for moistureless environments like Mars. But, the development cost for ad hoc Mars application is a high barrier.

Maybe a series of thin plastic layers that can be pulled inside a container every few months, sort of a carpet-umbrella.

Motorcycle racers use "tear aways" on their helmet visors. Thin plastic sheets that they can tear off and throw away when the visor gets too dirty.

(Not sure I'd want to deploy a system that intentionally litters single use plastics onto pristine planets though. We're already the species who spent way too long tossing old-fashioned non-biodegradable styrofoam cheeseburger containers out of 1967 Cadillac Eldorado Convertibles with whale-skin hubcaps getting 1mpg doing 110mph down the freeway...)

Might be able to use something like a toner transfer belt/blanket in a laser printer, with brushes and/or electrostatics to clean the belt as it cycles in a loop.

I mean, the alternative is littering dead rovers, so a little plastic sheet doesn't sound as bad

Arguably at least there's good purpose behind those...

<tin foil hat>And after all, they left the Pyramids and Stonehenge behind here, right???

Make it a cellophane type of substance that will dissolve in wate...oops. ;P

InSight is a non-mobile ground station, not a rover.

The rovers can position themselves such that wind removes dust.

So it only needed a "turn-table" base?

I'm sure it's not that simple, but I suspect that it simply isn't worth it to launch extra mass to Mars. InSight was successful in its mission, I don't know what value would be gained from extending its life further.

I always want to bike-shed this problem so bad. Brushes, electrostatic cleaners, vibrators, vortex generators, reel-to-reel plastic film over the panels...

There are so many things that seem like they would work but I know it's only because I don't understand the tradeoffs. In space tech, everything comes with a catch.

Is it easier to train a bunch of vacuum cleaners to be rovers or to train rovers to dust themselves off a little.

A MIT researcher recently devised an electrostatic solar cell cleaner.

https://news.mit.edu/2022/solar-panels-dust-magnets-0311

EDIT: sorry this is a repeat link

I wonder if they have any plans to try flying Ingenuity over Perseverance's solar panels to blow dust off?

Perservance doesn't have solar panels. It's powered by a radioisotope thermoelectric generator

I assume there are also worries about letting the helicopter fly near it, in case of damage

Perseverance uses an RTG (radioisotope thermal generator) and does not have solar panels.

And, as mentioned, you don't want the helicopter flying anywhere near the rover for fear it would collide and damage the rover.

Also, not really ironically, the helicopter's own solar panels (which sit above the rotor blades) are collecting dust, and that plus the lower sunlight during this part of the Martian year have significantly reduced power levels. They have had to implement measures to reduce power consumption, which will reduce the operating life of the internal batteries. It is possible we won't see any more flights, not sure yet.

wondering if rotating solar panel works. just rotate 180 degrees to dump sand to the ground and then back.

It's not actually sand, it's very fine electrically charged dust that "sticks" to the surfaces of the solar panels. Tipping the panels wouldn't help.

Apply a negative charge to the panels?

Now you just added another USD100M to the cost of the mission ;)

Reply on news.ycombinator.com