Massive Martian dust storm endangers NASA rover | Hacker News Reader

Massive Martian dust storm endangers NASA rover

nature.com

111 pointszerotosixty51 comments

I'll just link this short story: https://www.wired.com/2016/12/jon-rogers-a-martian-goes-hunt...

I am a bit confused by the "Massive" statement. I understand that Mars has barely any atmospheric pressure, therefore, any "Massive" storm would be a gentle wind.

If fact, Andy Weir, the author of the "Martian", called the beginning of the book where the hero gets stabbed by a metal rod during the massive storm a complete fabrication for the purposes of the story and impossible in real life.

I think they're calling it massive because the storm covers 1/4 of the planet and is still growing

Massive in extent, it covers large parts of the planet, and in duration, could last for weeks or months.

The threat to Opportunity isn't that the storm could rip it apart. It's that even a low-pressure wind can lift a lot of fine dust which blocks out the sun and leaves the rover without power from its solar panel. If it lasts too long the rover could literally freeze to death.

NASA has an image from another major storm in 2007 [1], it blocked 99% of the sunlight. This one is worse.[2]

[1] https://mars.nasa.gov/resources/7948/a-darkened-mars-sky/ [2] https://www.reddit.com/r/space/comments/8qvnrw/mars_rover_op...

As you say, direct damage from wind isn't a major risk on Mars, contrary to the book. However, dust storms do happen, and according to the article they can affect huge areas and block out most of the sunlight.

Is the idea that this one lasts long enough that it deposits sand on my friend's panels, and they doesn't have enough backup juice by then to move/clean it off?

From what I heard buildup on the panels isn't that big a deal because the wind also blows it away. But if sunlight is cut off too long the battery becomes empty and the heaters won't work anymore. So it would literally freeze to death.

The amount of light being blocked is supposed to be unusually high.

It's only letting 0.002% of sunlight through.

The endangerment part comes not due to the wind but from the dust, which blocks out the sun remarkably effectively and for extended periods of time. This is an existential threat for a solar powered probe. Opportunity won't get blown over, knocked around, nor impaled by a metal rod, but it will be (has been already) starved of power. There are key elements of the rover which require active heating, the rover is fully capable of "freezing to death" if it spends to long without power.

I'm intrigued by what research and plans have been made for how Martian colonists will deal with this sort of problem. I'm guessing solar won't be enough to keep a colony going. Wind power, even in a dust storm, wouldn't be possible because the air is so thin. Nuclear of some kind seems the only other option.

Maybe the Kilopower reactor [1]

[1]https://en.m.wikipedia.org/wiki/Kilopower

Summary of the linked Wikipedia entry: a nuclear heat source driving a Stirling Engine connected to a regular electric generator.

A test reactor has been constructed, called KRUSTY or Kilopower Reactor Using Stirling Technology. It is designed to produce up to 1 kilowatt of electric power and is about 6.5 feet tall (1.9 meters).[12] The goal of the KRUSTY experiment is to closely match the operational parameters that would be required in NASA deep space missions[13]. The prototype Kilopower uses a solid, cast uranium-235 reactor core, about the size of a paper towel roll. Reactor heat is transferred via passive sodium heat pipes, with the heat being converted to electricity by Stirling engines.

Sounds neat, I'd like one at home. Electricity is always handy, and the waste heat can be used to keep my house and cars warm.

Also cool: uses passive heat pipes rather than coolant, further reducing the number of moving parts (making it that much more reliable).

I still wouldn't want that much U-235 in a critical configuration in my home. If something goes wrong, I'm not a superfund site, I'm the reason why someone started WW3/why my neighbourhood is no more.

Why would it explode? Don't you need high purity and high compression with perfect timing for that? Wouldn't it just get really hot in a reactor design?

It's not easy to contain really hot things. If it gets out, it won't be a nuclear explosion but, if water or combustibles are around, there will be some sort of explosion.

Frankly I'd be more worried about "passive heat pipes filled with liquid sodium" (read: "pipes filled with substance that transmutes water to fire"). Not in my backyard.

In order to get a full-yield nuclear detonation, yes, but even a "fizzle" still has the power of a good-size conventional bomb.

A criticality event is _bad_. If you are near it, you get cancer. And there are many ways a small nuclear reactor can malfunction without that much yield, and still ruin my neighbourhood. I have to agree, the crater is the worst case.

Not to mention the whole no radiation shielding thing.

A quibble - in space applications, "nuclear heat source" makes me think a radioisotope thermal generator (i.e. a lump of an unstable isotope decaying naturally). That's what's used on the Curiosity and Mars 2020 rovers. Kilopower, on the other hand, is a for-real, critical-mass nuclear reactor.

That's a good point. Too late you edit my comment now, but I agree it should have said something like "heat from a nuclear reactor ...'

As awesome as the Kilopower reactor is, this really isn't its intended use-case - it's supposed to provide low-output, very longterm power in spacecraft and rovers, where mass is limited, shielding unnecessary, and maintenance impossible. For mars colonization, a significantly larger purpose-built reactor would be much more feasible, and almost certainly a better solution than solar.

This article[1] used as a reference in the Wikipedia entry certainly makes it sound like Mars colony is Kilopower's intended use-case.

1. https://www.space.com/37348-nasa-fission-power-mars-colony.h...

I stand corrected! Previous articles I had seen had only discussed the prototype and one kilowatt design, but both this and the Wikipedia article show heavier designs for Mars missions.

The article doesn't say what the exact power drop is, but it appears to have been at least 75%:

> Within days, Opportunity saw sunlight dimming as atmospheric opacity — a measure of how much dust is in the air — soared. The rover’s energy production dropped by half over the course of 2 days, and then half again in a single day, Callas said during a media briefing on 13 June.

Aside from nuclear, some reasonable mitigations for this kind of thing might include substantial over-provisioning of panels, some kind of battery, or some kind of temporary measures to consume very little energy in an emergency.

I think over-provisioning might actually be the most practical solution, particularly if any Martian settlement needs a massive solar farm anyways in order to produce electricity to convert water and carbon dioxide into methane and liquid oxygen. Making rocket fuel is important, but not so important that it can't be curtailed for a few weeks if that energy is needed elsewhere.

> An optimized system of this design massing 50 kg "is projected to produce 1 kg/day of O2:CH4 propellant ... with a methane purity of 98+% while consuming 700 Watts of electrical power." Overall unit conversion rate expected from the optimized system is one tonne of propellant per 17 MWh energy input.

https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin...

Burning rocket fuel to generate electricity might also be an option if there's a temporary shortage.

Exactly this - giant solar farm for rocket fuel production, turn it off at night, turn it down or off during dust storms. Rocket fuel could be used during these lulls (nights/storms) to provide power, maybe recapturing the exhaust gases as pure feedstock.

edit - batteries might be the better option for overnight, but would have serious mass penalty to use for long term backup power. Using fuel as storage is simple solution.

Power from combustion seems like a bit of a tough sell in an environment severely lacking in O2. Then you also need to bring some sort of high efficiency engine (probably an LNG turbine) with you too with an appropriately sized generator. Capturing exhaust gasses is a neat idea, but now you need to bring compressors and high pressure storage tanks with you.

O2 isn't the only way to do combustion. There is also a fair few of autooxidizing materials (monopropellant) which require nothing but a spark to burn up, no oxidizer necessary.

But like with O2, it's all dangerous to contain as it easily burns without much options to extinguish (esp. Flourine Compounds are nasty and some will burn up sand, fireblankets, water and your fire extinguisher)

If you have locally manufactured fuel that can be used in a rocket, that fuel is going to include an oxidizer; e.g. the SpaceX plan is to manufacture methalox (methane + liquid oxygen) and store both of them.

Overprovisioning probably won't help.

The power drop isn't 75% it's nearly 100%. The last image transmitted is pitch black only the camera's sensor introducing some noise during the long exposure to be visible.

The mitigation is either "lots of batteries" or "have a (nuclear) generator and power down" because solar will not produce anything under the currently present conditions.

(Well not "nothing", it's generating a couple milliwatts, enough to drive the rover's internal timer so it can periodically check if it's charging batteries)

Yeah, that's a good point; I saw that later in another comment that illumination on the ground was almost nothing.

I guess burning rocket fuel for electricity/heat is probably the most practical mitigation. I expect it would be tremendously inefficient, but better than freezing due to a once-a-decade dust storm.

Lots of batteries or nuclear could also work if it's available.

> Wind power, even in a dust storm, wouldn't be possible because the air is so thin.

From what I've read around the web, it actually would be possible. The efficiency would be around 10% of an equivalent wind turbine on Earth, but it has one thing in its favor: you could construct them with mostly local resources even at early stages of a Mars colony. PV cells are too high-tech for that, they would have to be shipped from Earth.

https://space.stackexchange.com/a/5669

https://www.youtube.com/watch?v=0xtW7g4R_vs

They might be able to store excess energy using a gravity system https://www.planetforward.org/tv-segments/storing-excess-pow...

TL;DR -- The issue is lack of sunlight rather than damage from dust or blanketing of the solar panels.

I was curious if Opportunity has a way to clean its solar panels. Answer: no, but sometimes a wind gust helps out.

https://www.quora.com/How-does-a-Mars-rover-manage-to-clean-...

Curiosity doesn't have solar panels but rather a "radioisotope thermal generator".

JPL has a recording of the 13th press conference here:

https://www.youtube.com/watch?v=fIKxdRFx2Wo

Do dust storms only occur on planets with an atmosphere? And does their severity depend on how dense the atmosphere is?

IANAAstronomer but I would imagine the atmosphere is necessary for both the suspension of dust particles and the propulsion of dust particles.

Impacts by asteroids, meteoriod, etc. could raise dust clouds.

Dust particles achieving orbital velocity would be sufficient too (small moons, this is possible)

From https://saturn.jpl.nasa.gov/news/1206/kicking-up-dust-saturn...:

"The planetary magnetosphere comes into play with the charged dust particles. The rotation of Saturn’s magnetic field generates an electric field directed radially outward from the planet. This field will eject small, electrically charged particles, into interplanetary space. Once that happens, the interplanetary magnetic field “frozen” into the solar wind can accelerate the dust particles to high speeds, creating the bursts of particles recorded by cosmic dust detectors. Evidence for this interpretation came from the changes in direction of the stream particles when the interplanetary magnetic field changed direction, in close timing with the Sun’s rotation."

So my guess is that a planet with no atmosphere and a magnetosphere weak enough to accelerate the charged dust just only enough to keep it moving without being ejected of the planet could have something happening, I'm not a planetary scientist and I don't know if a storm would be plausible so take it with a grain of salt and hope for someone else to jump on the question.

But if we're talking about "common" dust storms, without an atmosphere there would be no winds, so no common storms, and since air density in Mars is much lower than Earth (around 1% of ours), high speed storms in Mars would not be as severe as in Earth, wind speeds that would turn a car or rip trees on Earth wouldn't even push a human out of his place in Mars.

Our Moon has "sort of" dust storms of ionized dust. They are driven by electric charge from ionizing solar wind rather than an actual atmosphere.

The story reads like a movie and everybody seems to just believe it. It's interesting to watch something unfold that has absolutely no evidence and still people believe it's true based on trust alone.

All the Flat earth like societies could invest in some equipment and prove once and for all the truth about what the claim is.

“It’s like you have a loved one in a coma in the hospital, and you have the doctors telling you you just have to give it time and she’ll wake up,” says Callas. “But if it’s your 97-year-old grandmother, you’re going to be very concerned, and we are. By no means are we out of the woods.”

This is just a sad analogy. Yes, let's compare the life of a robot to the one of a human being.

The life of a human being can be evaluated in terms of how many people they've interacted with, the influence they've had on those peoples' lives, and the lasting memories that people carry with them once that human has gone.

It is quite possible to apply the same metrics to "a robot" (which is actually an entire science program at JPL), and see that this program has affected the lives of many more people than most humans ever will. There are people whose entire careers have been based on this program, and the community of technicians, scientists, engineers, administrators etc around the robot is just as real as the community around any person.

If this robot ceases functioning, the entire project stops, careers are ended, and a community is fractured. To this community the robot is just as important as any human.

Your lame attempt at concern trolling shows very little respect for the community involved in this project.

Not to mention that far more than a lifetime has been collectively invested in it. Given its budget of $400M, and assuming an engineer costs roughly $1,000/day, we have about 1000 people-years invested in this project.

A modern day pyramid: monumental sacrifice and sights to behold.

Not to mention the rest of us. The razor sharp images from the twin rovers have been a constant source of awe and wonder for the last fifteen years. For me, these almost snapshots really helped establish Mars as a place, as somehwere, just like anywhere else. Thank you, America. One of your nicer cultural exports.

How is this trolling?

Put in to perspective, I'm not diminishing the work accomplished, I'm simply criticizing the comparison. Would you do such comparison if it was towards a person you know?

"Oh, your brother is in a coma? How sad, it's just like when Mar's rover went through that sand storm.. .don't worry it he will wake up any moment".

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