Comment by tsimionescu | Hacker News Reader

Comment by tsimionescu | Hacker News Reader

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As the article points out, that's not even in the top 100 things.

Having a self-sustaining living space is by far the biggest problem (one where all of the waste we produce can be reused to create new drinkable water, air and food, and to reliably continue to do so between Mars launch windows).

The second biggest is probably avoiding contamination of Mars, if we actually care about exploring one of the biggest mysteries of life - has it arisen only on Earth? Are there other modes of life possible, and what do they look like?

The third biggest challenge is human psychology and physiology - could we actually get a group of ~100 people or however many we need initially to live and be productive for the years-long space mission (including travel time to and from)? What do we do when at least one of them inevitably gets sick on Mars?

Each of these problems is fractally more complex than I make it out to be, and none of them would be fixable if rockets were very cheap. And these are just problems for a limited time Martian outpost, similar to a trip to the ISS. Thinking about an actual colony with some prospect of perpetual habitation being in orders of magnitude more issues, some of which may not even be solvable without biologically altering humans to make a new Mars-adapted species of hominid.

None of issues you listed matter at all if launching stuff to space is cost prohibitive.

Without cheap space access they are not even worth properly researching.

> One where all of the waste we produce can be reused to create new drinkable water, air and food, and to reliably continue to do so between Mars launch windows.

None of that is as big of an issue if you can launch often and a lot of stuff. In the limit you don't need to recycle anything and everything has multiple spares. You can also launch outside direct constraints of Hohmann transfer orbit. Again, payload limitations and time are the main reasons we use Hohmann transfer orbits.

> The second biggest is probably avoiding contamination of Mars, if we actually care about exploring one of the biggest mysteries of life - has it arisen only on Earth? Are there other modes of life possible, and what do they look like?

We will not avoid contamination. It's impossible to do. Where humans go our microbiome will follow.

I personally think we should intentionally seed all celestial bodies with life as soon as possible anyway.

If we find life in our solar system (especially life independent from Earth) we should become a lot more aggressive with space settlement, because it would make "great filter" ahead of us hypothesis a lot more likely. Settlement outside solar system should become one of humanity priorities as a matter of survival.

https://en.wikipedia.org/wiki/Great_Filter

> The third biggest challenge is human psychology and physiology

Going to Mars can be a suicide mission and you will still find people who will be willing to go.

Not a showstopper for the willing.

> Thinking about an actual colony with some prospect of perpetual habitation being in orders of magnitude more issues

First things first.

> Without cheap space access they are not even worth properly researching.

On the contrary - these are all useful technologies to the goal of preserving human life. If we had the ability to create self-sustaining colonies in the most extremely harsh conditions on Earth (a necessary step to being able to colonize any other place), we would have a much greater guarantee that humanity would survive a disaster like a huge asteroid/super volcano/deadly plague/etc. We could probably also use the technologies developed for other uses - better homes, more sustainable agriculture etc.

We could also work on miniaturizing the things and then start thinking about sending them in space, perhaps even with currently existing rockets.

> None of that is as big of an issue if you can launch often and a lot of stuff. In the limit you don't need to recycle anything and everything has multiple spares. You can also launch outside direct constraints of Hohmann transfer orbit. Again, payload limitations and time are the main reasons we use Hohmann transfer orbits.

It's far less likely that it's possible to reach the level of cheapness you talk about at all, given the hard physical constraints on rocket masses and available fuels.

> We will not avoid contamination. It's impossible to do. Where humans go our microbiome will follow.

Exactly - hence why humans shouldn't be going to Mars until we have studied the hell out of any possible local life and become convinced we have learned all we can on the subject.

> Going to Mars can be a suicide mission and you will still find people who will be willing to go.

What would be the goals of the mission? Why do you think people desperate enough to accept certain death will be able to achieve said goals or even care about them once they reach the surface?

> First things first.

Exactly my (and the article's) point. First you send robots to Mars while developing colony technologies on Earth, then you start thinking about sending humans to Mars.

> Exactly - hence why humans shouldn't be going to Mars until we have studied the hell out of any possible local life and become convinced we have learned all we can on the subject.

That's not how people work. People will go to Mars for curiosity, greed, fame, or some higher level desire (possibly religious) not necessarily in that order.

Odds of Mars being explored à la Star Trek are infinitesimal, I'd give that hope up.

We can explore how life appeared on planets in other solar systems.

It has worked so far for Antarctica, and saying "it's never going to work" while advocating for it not working is not a convincing argument.

It has worked due to the treaty being worked out in early cold war, when both East and West were already planning military operations and bases in Antarctica - that way, neither side could have it and they were fine with it, sparing a considerable expense.

It has held in place since then by both inertia & similar "if I can't have the resources, no one can" and other resource sources still being usually cheaper to mine.

> What would be the goals of the mission?

Showing that's it's possible right now within reasonable budget.

That's the fundamental difference in logic here.

The goal is to get people to Mars as soon as possible. Not to delay it for as long as possible.

> Exactly - hence why humans shouldn't be going to Mars until we have studied the hell out of any possible local life and become convinced we have learned all we can on the subject.

This is never going to happen. Even on Earth people are not 100% convinced that "shadow biosphere" doesn't exists.

https://en.wikipedia.org/wiki/Shadow_biosphere

> It's far less likely that it's possible to reach the level of cheapness you talk about at all

Starship HLS right now is being build with aim at 100 metric tonnes to the Moon vs. NASA requirement of 2 metric tonnes.

Starship HLS allows to take 50x spares of everything NASA thought would be required for the Moon landing.

And it's costing NASA as much as gross earning of the Avatar movie - $2.9B.

> The goal is to get people to Mars as soon as possible. Not to delay it for as long as possible.

To what end? We could send a few suicidal people to Mars today for little more than the cost of a satellite launch if we don't care about their survival - hell, they don't even have to be suicidal, get some people who recently died, strap them in a rocket, and send them to Mars.

Instead, you have to set an actual short term and longer term mission goal - say, you want a mission that can prove that X people can survive for Y months on Mars without external help, with a longer term goal of hauling them back to Earth at the next launch window or something.

But for this type of mission, you actually need extremely sane people who greatly value their lives and those of their colleagues, otherwise you'll just have a few corpses sitting on Mars like in my initial example.

And more importantly, again, given current technologies, the actual result of the experiment is already known: those people will simply die if sent to Mars with currently known life preservation methods.

> This is never going to happen. Even on Earth people are not 100% convinced that "shadow biosphere" doesn't exists.

Then never send people to Mars - at least not until we have a very clear path to actually establishing a self-sufficient colon on Mars, for which there is plenty of research that can be done on Earth (and in LEO).

> Starship HLS right now is being build with aim at 100 metric tonnes to the Moon vs. NASA requirement of 2 metric tonnes.

Let's see it fly and let's see the total budget before such hopeful conclusions. Let's also see it actually successfully do orbital refueling, which would be a prerequisite for even getting to the moon with the proposed design, not to mention Mars.

And even if Starship achieves all of its goals, it will be nowhere near the ability to send resources to Mars outside the existing launch windows in anything approaching economic efficiency.

You are arguing against strawman. I'm telling you that there is willingness to accept as high risk as it is necessary. Not that we should be aiming at sending suicide squads to Mars.

> for which there is plenty of research that can be done on Earth (and in LEO).

Everybody is welcomed to do the research on Earth. And Starship will make LEO based research some 100x cheaper.

$100B for ISS vs. ~$1B for Starship in a pessimistic scenario. ISS and Starship have similar usable internal volume.

> Let's also see it actually successfully do orbital refueling, which would be a prerequisite for even getting to the moon with the proposed design, not to mention Mars.

Exactly. Working hardware silences detractors better than anything.

SpaceX won that contract including all the legal challenges a bit over a year ago. Give them some time.

> Let's see it fly and let's see the total budget before such hopeful conclusions.

It's a fixed cost contract, not cost+ like SLS which BTW costs NASA 4 billions per launch all things considered according to their own estimates.

> Settlement outside solar system should become one of humanity priorities as a matter of survival.

> Going to Mars can be a suicide mission

These goals seem contradictory.

> Having a self-sustaining living space is by far the biggest problem (one where all of the waste we produce can be reused to create new drinkable water, air and food, and to reliably continue to do so between Mars launch windows).

That problem gets a lot easier and cheaper when you don't have to design for margins of 1.2 to or so to save on weight. When you can throw extra weight at a problem to overbuild it for reliability you can solve these problems cheaper and more reliably.

> The second biggest is probably avoiding contamination of Mars, if we actually care about exploring one of the biggest mysteries of life - has it arisen only on Earth? Are there other modes of life possible, and what do they look like?

Planetary Protection is the new version of treating Earth as "gaia". It's a form of regressive environmentalism. This is not an important goal. Mars is not a very good candidate for supporting life now that we know how many geothermally active ice moons with undersea oceans exist in our solar system.

If hypothetical life on Mars is similar to life on Earth then it's not that valuable of a thing to learn and anything found would vary drastically from life on Earth from billions of years of separate evolution. If it's very different from life on Earth then it will still be easy to find even with plentiful human contamination.

Finally, with additional mass you can bring substantially heavier and more complex analysis and remote robotic equipment with you. (Or on a completely separate mission before humans arrive.)

> The third biggest challenge is human psychology and physiology - could we actually get a group of ~100 people or however many we need initially to live and be productive for the years-long space mission (including travel time to and from)? What do we do when at least one of them inevitably gets sick on Mars?

This is overrated given that there's plentiful human experience throughout the history of humanity where humans suffered significantly worse isolation and hardship. Some projects will fail from human psychological issues, and the risk from them should be minimized (bring plants along, allow spaces for people to self-isolate, etc) but a single failure should not be taken as a reason that the entire concept is doomed. For sickness, you try to minimize possible issues by bringing significant medication and medical equipment, but sometimes there will be inevitable deaths. As mentioned, having additional mass that you can bring for human comforts and medical equipment saves a lot of potential deaths and issues

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