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Comment by usrbinbash | Hacker News Reader

> There are nitrates on mars

The martian atmosphere is 2.8% N2. For comparison, Earths atmoshpere is 78.08% N2, while also being more than 100x as dense. And Earth already has soil, and a developed nitrogen cycle, while Mars doesn't.

So there is nowhere near enough Nitrogen in-situ on Mars to support any form of agriculture. It has to be brought from Earth.

> mars has enough gravity to prevent bone loss

https://www.ucsf.edu/news/2017/07/407806/traveling-mars-will...

So yes, lowered gravity has negative impacts on our bones and physiology in general. The gravity on Mars is 1/3 that of Earth. And that's after spending several months in-transit at microgravity.

> But yes, it does mean bringing your own air and being self sufficient, but we do both of those things on the ISS already

The ISS is not self sufficient, and relies on continuos supply runs from earth: https://en.wikipedia.org/wiki/Uncrewed_spaceflights_to_the_I...

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Nitrates on earth range from 10-50 mg/kg in soil, on mars they make up 1100ppm = 0.1% = 1mg/kg, so in the extreme you can convert 10% of martian land to soil. Seems like plenty.

We just don’t know if the 1/3 gravity will cause bone loss problems - going to the moon is the best way to study it, but who knows. Probably, people will just age 3x faster in terms of bone mass on mars. https://en.m.wikipedia.org/wiki/Spaceflight_osteopenia

And yeah, the first years of a mars colony are gonna be dependent on earth. We’d definitely make sure we have enough rockets that they can abort if shit goes south on supply missions, but there’s no reason earth can’t supply them at first.

Nitrogen in Earths soil is present in the form of Ammonia, and derived substances. Occurring naturally, it is the product of microbial nitrogen fixation of diazotrophic bacteria, and subsequent biological processing. Plants can use these compounds directly.

Nitrates on mars will probably be in the form of nitrate salts.

Btw. agriculture also requires soil. Which the martian regolith isn't.

> We’d definitely make sure we have enough rockets that they can abort if shit goes south on supply missions

Have enough rockets where? On mars? Using what fuel? Using what ground installations like scaffolds and launch pads? Also, launching between Mars and Earth is only possible during specific time windows. For an Earth-Mars transit, these occur ~once every 2 years. So if "shit goes south" outside these windows, the amount of rockets won't matter.

> Also, launching between Mars and Earth is only possible during specific time windows.

No. It is always possible, but the optimal windows happen every two years. There is another 2nd optimal window, that happens every 5.5 months, which flies by Venus before continuing on to Earth/Mars.

You are of course correct. I should have said: The lowest energy option for a Mars transfer happens every 24 months.

Transfer outside that window is possible, but requires more energy, which increases the transfer time, limits the payload, or both.

Earth crust has relatively small amounts of iron, or nickel, or silver, but it has areas with high concentration of these, so large as to enable massive metallurgy on Earth.

Chances are, Mars may have local concentrations of nitrous minerals (as does Earth), and these can be used to run a large enough agriculture. Few plants know how to consume atmospheric nitrogen anyway.

Air pressure and temperature can be maintained below transparent domes, greenhouse-style.

Dim sunlight looks like a much bigger problem, which can't be fixed by any terraforming.

> Chances are, Mars may have local concentrations of nitrous minerals

Which would have to be found, ideally near the equator (otherwise landing and solar power generation is going to be a problem), mined and transported. And since Nitrous minerals aren't fertilizer, it would have to be processed (which is an energy intensive process even on earth, where we get to use atmospheric Nitrogen in the Haber-Bosch-Process).

And of course there is no soil on mars, so we have to bring that as well.

Indeed! This turns a nigh-impossible task into a just technically very hard one.

Of course we won't be able to do this now, and still won't be in 10-15 years. In 30 years it's hard to predict: there can be a huge technological breakthrough, or a total loss of interest and regress in capabilities.

Well, it's "a just technically very hard one" right now. Because, we could, technically, just send fertilizer, and soil, from Earth.

The question I am asking isn't "is it possible". The question I am asking is "is it worth it". I see a lot of comparisons with Columbus, colonising America and the first Lunar landing flying around in such discussions. Well, all of these, and in fact most grand far-fetched undertakings of mankind, as un-romantic as that may sound, were the result of a cost-benefit analysis;

Columbus expected to find a valueable trade-route.

Colonising America promised resources, taxes and geopolitical power.

Landing on the Moon showed off who got the biggest most badass rockets to a geostrategic opponent in the middle of a cold war centered around, well, rockets. There is a reason no man has been on the moon since the 70s.

Trying to colonise Mars promises...what exactly?

Colonizing Mars for real (that is, building a self-sustained habitat there) is a way to create a habitat not controlled by any Earth government. That's the only potential upside I see in the short term, an upside for those who care about such things and are ready to pay an immense price for it. Something that a bunch of eccentric libertarian-leaning billionaires might do. (Oh wait.) Large and unconventional religious movements could be interested, too, like Puritans of old, but much more well-funded and determined.

> is a way to create a habitat not controlled by any Earth government.

Yeah, a few tiny problems with that assumption:

a) Earth goverments can easily shut down launches from Earth. Since any Mars Base would be dependent on resupply for probably a very long time, that effectively gives them control.

b) Establishing a Mars Base doesn't work without government support to begin with, so they have their hands in from the start. And even if they didn't, being ruled by a corporation or billionaire overlord instead of a government would be a prime example of "Out of the frying pan - into the fire".

c) In a bid for Braveheart-Style "Freeeedoooooom!", Mars colony has no leverage over Earth. Zero. There is no Unobtainium on Mars.

d) Any ungoverned, larger group of humans, left to its own devices, will eventually form some kind of government, if only out of the need for self-organisation. Proof: The entirety of history.

Regarding d); Now, our Earth governments may not be ideal solutions. And yes, maaaaybe Mars Gov. will be an ideal utopia. I kinda doubt it.

Because that group would be under constant psychological pressure from several life-threatening dangers, where one mistake by one person could kill everyone. They live in a planet-sized dead wasteland, with very limited resources. They are locked in crowded habitats for most of the time. Their lifespan is likley cut short by radiation damage and low-gravity related physiological deterioration.

Now, I am not a psychologist, nor a political scientist. But under such conditions, I imagine the outcome of any government-formation-process to be...unpleasant.

Boston was founded in 1615, and the US declared independence in 1776. A colony will depend on the mother country / planet for quite some time, but has a chance to become materially independent in 150+ years, too.

I'm not saying that this desire is rational, or that the result would be a libertarian utopia, etc. But "all progress depends on the unreasonable man", as history also shows time and time again.

> A colony will depend on the mother country / planet for quite some time, but has a chance to become materially independent in 150+ years

Boston was founded in a breathable atmosphere and a livable climate, in a land that contains building materials, wildlife, liquid water, and arable soil, all shielded from cosmic radiation by Earths magnetic field and in a gravity well our physiology has evolved to cope with.

Yes, life for the colonists was hardship and back-breaking work, but the basic building blocks for survival existed.

Which of these blocks are present on Mars?

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