Maybe that's not liquid water on Mars after all | Hacker News Reader

Maybe that's not liquid water on Mars after all

phys.org

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Is there a reason we have not yet explored it directly with a rover? Aren’t there multiple rovers on mars? Surely taking samples from this ice is more important than examining rocks??

Because launching a robot is a multi billion dollar affair and the robots we have launched are very far from the south pole. This is a whole planet after all, and they move on the scale of meters per second for maybe a few hours / day.

> Because launching a robot is a multi billion dollar affair

They don't have to be though. Spirit and Opportunity entire project budget (including design, building, launching, and operating for 90 days) was 820M. Even with the mission extensions the total cost is < 1B. And a lot of things have changed since then. Launches are cheaper, tech has improved and some recent missions have proven that even CotS hardware can exceed expectations (see the helicopter).

I would love to see NASA do something like the CLPS but for Mars. They could pay for launch services (which are way cheaper now with F9 / NG), and help with EDL (using the same parachute + airbags thing that has worked before), and leave the rover parts to 3rd parties.

We could have universities join the competition, building the rovers, exploring CotS stuff, autonomous driving and so on. Lower stakes than the decadal big rovers (Curiosity & Perseverance), but also cool and useful to train the next generations of students. Hell, I bet even companies could enter the race, with Toyota / Tesla / whoever else supporting this effort.

I like that idea, would you volunteer to convince Musk to personally do a Full Self-Driving demo on Mars? Teslas would sell like hotcakes, tell him that. One can still hope.

No pedestrians. No traffic. No traffic signs and rules. No hurry. Self-driving on Mars should be a piece of cake, compared to SF.

> They could pay for launch services (which are way cheaper now with F9 / NG)

Are either of the rockets mentioned capable of launching a payload to Mars? The Tesla was launched on a Heavy which is 3 F9s. While maybe cheaper than a Shuttle launch, it's still at least 3x the F9 you're suggesting

A Falcon Heavy launch is about 30% more expensive than a Falcon 9 launch, given the reusable mode. I suppose it's the servicing the launch that costs most, not the fuel or insurance premia.

Yes. F9 has a catalog payload to mars of 4020 kg [1] and Spirit and Opportunity had a total mass of 1,063 kg [2] each. So an F9 launch could easily launch 3 similar missions on a single rocket (the MERs were launched separately on Delta II rockets). Squeeze out some weight (material advances, fuel optimisations, better transfer windows, etc) and you could probably get 4.

Anyway, in a CLPS type program you could also cover kickstage development, like some of the new companies are proposing. Impulse Space is working in that area, developing intermediary stages that can take payloads from LEO to GEO, TLI and TMI.

[1] - https://www.spacex.com/assets/media/Capabilities&Services.pd...

[2] - https://en.wikipedia.org/wiki/Mars_Exploration_Rover

What I'd like to see is a stationary lab / communication relay that processes samples that are brought to it by a variety of rovers that can be launched with the lab or in other missions.

It would be neat to see different companies, schools, or nations come up with variations on the rovers that only need to support the common interface of passing materials to the lab for analysis.

You could even drop more labs and build a network of them and expanding the range of your little rover nodes.

Once you have a decent rover design sorted out you can work on mass producing it and achieving economies of scale.

> they move on the scale of meters per second

That’s still 2 or 3 orders of magnitude too high. The top speed of the Perseverance and Curiosity rovers is around 45 millimeters per second.

Yeah seconds per meter would be a more appropriate measure.

I assume because of the conditions on Mars. The ice could actually be much deeper than thought.

The furthest distance a robot on mars has traveled from its landing position isn't even 50km. Over many, many years.

For example, on Nasa's website it says this about Perseverance:

> This map view shows the route NASA’s Perseverance Mars rover has taken since its February 2021 landing at Jezero Crater to July 2024, when it took its “Cheyava Falls” sample. As of October 2024, the rover has driven over 30 kilometers (18.65 miles), and has collected 24 samples of rock and regolith as well as one air sample.

That's about 8.5km per year.

So I think they would have to land a new one pretty close.

Why does it move so slow?

Isn't it solar powered? So it could just keep moving in the right direction?

The two solar powered ones are decommissioned, both mostly because of diminishing power but one got stuck first. Away from the equator solar power is less effective right? And it's colder, which exacerbates a serious problem: most the energy goes to heating the main components.

The nuclear rovers are doing their assigned missions, and can go about 100m/day IIRC. So, 5000km trek to the pole would take about 50,000 days at 10d/km. Give or take a few thousand km. (It's a whole planet right?)

This is all Wikipedia level research and from memory.

You really don't want the vehicle to get stuck. Recovery may be impossible.

Unfortunately, the roadway infrastructure on Mars hasn’t been updated in decades, so there are lots of rocks and potholes/craters and other obstacles that need to be avoided. You know how those jeeps go out to Moab, Utah and do the 4x4 trails? It’s like that but there’s only one vehicle and no human and 1 hour communication round-trip and if something goes wrong the tow truck is millions of miles and billions of dollars away

One major issue with transportation in the Martian environment is the extremely abrasive dust and the sharp rocks. Pretty much every rover has had the issue that the wheels deteriorate very quickly and dust gets into every nook and cranny, eventuelly destroying important movement-related mechanisms. As to their movement speed, that's mostly down to the movement being manually commanded and with the light delay of about 20 mins (one-way), you can only command the rover to go so far before involuntarily hitting an object.

This doesn’t bode well for any human base there does it? We will have these same abrasive dust problems on human movers and machines.

The dust on the Moon will be even worse.

why? there's less wind. supposedly, the astronaut footprints are expected to remain intact for quite a long time because of it.

Exactly. There is no wind. All the little solidified impact glass particles, with their razor sharp microscopic edges, have not been smoothed by even the slightest wind erosion.

I recall reading that a major candidate for any early colony is in lava tubes, dust on the would be one factor, but radiation shielding is another. Either you have to ship materials from Earth and build them, consume whatever is available and useful locally, or make use of whatever Mars-nature provides. If you can get away with lighter materials to build below surface then it seems better compared to more durability/shielding requirements above.

Humans are better at cleaning than robots.

The rovers are controlled remotely, so imagine playing a video game where your inputs lag by upwards of 40 minutes and you can't crash.

They have metal wheels that wear out. Even given unlimited power they would no longer be capable of movement after enough wheel/tire wear.

The Jezero crater where the Perseverance rover has been roaming looks a lot like it was a lake and was expected to tell us whether Mars has held life. It was a good guess because the rover has found clay and organic molecules.

Human habitation on Mars is a pipe dream for oligarchs, most serious space people are more interested in extraterrestrial life and the history of the solar system.

> Human habitation on Mars is a pipe dream for oligarchs

It’s just the one oligarch in particular, isn’t it?

It is noteworthy though that the causality goes the other way: the crazy one pipe dreaming about a city on Mars had this dream first and then became an oligarch to make it reality.

It seems doubtful to me that that was his main motivation. Afaict he didn’t express interest in Mars publicly until around the time of his PayPal exit.

That said, it’s true that belief in fantasies can motivate people in powerful ways. All the old cathedrals in Europe are a testament to that.

And those cathedrals will outlast a lot of buildings from twenty years ago.

You say that, but I once suggested that humans weren't going to colonize Mars in this century, and got downvoted - here on HN.

A lot of people seem to think, hmm, we've been watching fictional people go to Mars since Buck Rogers; it must be pretty achievable. (Hint: it's not.)

I think I read somewhere that we have so far stayed away from regions that could support life in order to reduce the risk of contamination? I hope that future missions will be as responsible but there's the danger they won't be.

Because ice surfaces can be very unsafe for equipment. There can hidden gas pockets in them, chasms and other unstable surfaces.

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