How Will We Get Off Mars?
news.nationalgeographic.com
news.nationalgeographic.com
— Captain Kathryn Janeway, One Small Step, Star Trek Voyager Season 6, Episode 8
(Previously: https://news.ycombinator.com/item?id=8751282)
Sadly its not a popular exercise to say "We're spending billions to send a bunch of solar panels to mars, though no one will use them for decades..."
And with this you completely miss the reason why we need to colonize away from our planet.
What if a catastrophic event completely destroyed all life on Earth - the poles included? All of humanity. Wiped out in a single event. Getting people onto Mars is the first step to making sure humans can continue to exist in such an event.
A catastrophic event isn't going to stop and think "Oh hey, humans are treating each other nicely. Maybe I shouldn't wipe them all out?"
The continuation and survival of the human race is the top priority among a large population of people. Some contribute by researching new medicines (Why do this?), others improve quality of life for others (Why do this?), others have children (Why do this?), and others look for a way to get us away from a potentially doomed planet in case of disaster scenarios. They all have the same reasoning - just different methods.
Morals are subjective to a population. The majority population of humanity has decided that continuation of "us" is a "good thing".
Of course, one could argue things would be better off if humanity went extinct. But that isn't in humanities' best interests (read: survival), so people generally wouldn't agree with you.
The vast majority of medical research goes to diseases that pose no existential threat to Homo Sapiens. Even Malaria, which kills upwards of 500,000/yr, does not pose any existential threat. Late-life diseases such as alzheimers have no effect whatsoever on Homo Sapiens, yet receive substantial funding. No, medical research largely serves to decrease human suffering, a goal which I do regard as noble.
Likewise, why does increasing quality of life matter? Humans will continue to reproduce even in conditions of abject poverty. What does quality of life have to do with anything? (You, after all, seem to think putting humans in a thin metal tube and hurling them through space to live out their life on a cold, barren rock is important. Surely you don't think this would increase their quality of life).
As for children, I have no clue what people see in them. But they seem to reproduce because having children makes them happy, not out of some perceived obligation to Homo Sapiens.
My point isn't that you need to share my morals. My point is that you should acknowledge your morals are not universal.
The goal of colonizing another planet would give a small subset of people the ability to continue living if the people on Earth were to destroy themselves. This is a hypothetical situation that -if it happens- will kill off almost everyone, dragging hopes, dreams, money, infrastructure, standards of living (basically everything that makes life enjoyable) with it. So if that is destroyed, why does it matter if humans continue living as a species? Especially on an extremely harsh planet.
Your analogous examples differ because all of those things -medicine, quality of life, children, even sustaining our environment- help us now. We do those things to make our own lives longer, improve our own children's lives, and make our quality of life greater, not some hypothetical future civilization away from Earth. You're right that humanity's best interest is survival, but I think way more people are concerned with their own survival and I think that's where the true incentives for those examples lie.
If I cared about perpetuating my DNA, I'd donate to sperm banks to produce more genetic offspring than I have any hope of supporting on my own. From the Darwinian perspective, I would be regarded as enormously successful.
Colonizing the Artic/Antartic is way cheaper than Mars, and would help us pick most of the low hanging fruit research for a fraction of the cost. We can always do Mars later if that is the way history turned out.
Not to mention that there are much more dire and certain risks today, which will likely cause huge loss of life and property (like climate change, or resource depletion, or geopolitical instability). But because those are not extinction level events, people do not freak out about them and little mitigation is being done.
For a non-return mission, there are so many unknowns. We have barely a clue on how to sustain a human body on such a far away place nutritionally, psychologically and medically. If we were to send humans to Mars to grow old there, there will be so many unknowns that they will likely die quickly and helplessly due to some aspect of Mars missions we are ignorant of. It is running an experiment with human lives. Given that we know so little about the risks involved, I think it's unethical to send people there like that. Even if people choose for this themselves, it becomes at best unhelpful for humanity's view of space exploration to see people die helplessly on some remote world because we were running a grand experiment.
Sending people to Mars, and ending up having to say "Wow, we did not see that coming" is not something that will benefit humanity. We are not even close to being well-prepared enough for such a mission to become a success.
Moreover, return missions are a way to actually prepare the colonization experiment. Colonization can be the next step once longer and longer return missions give us the vital information we need about how living on Mars works for humans.
Return missions are something we know we can do. We know how to sustain humans for days in environments like outer space and the moon, places far more hostile than Mars (the trip to Mars will likely be far more hostile than actually being there on the surface). We just need to solve an engineering problem.
I also think you are overestimating our robotics. A trained geologist on the surface of Mars for a few weeks with a suitcase of instruments and e-mail access would give us exponentially more information than all previous Mars missions combined.
So your opinion is a good one, but will not impress the big masses. The same held for the moon. A purely political accomplishment for the US. And a big one.
Colonizing the Mars with the current rocket tech will not work. But maybe with the upcoming ion drives. They look good.
DS1 didn't go to Mars. I did work on the research program that was the precursor to the Sojourner mission, but I didn't work on any of the Mars missions themselves. So I haven't been to Mars any more than anyone else.
I'm not sure that's the case anymore, we've had so many successful robotic missions - to Mars, other planets, comets, etc. - that all captivate the public for a span and return valuable data for subsequent mission planning. Pretty sure PR is neutral factor now in deciding on human vs robot missions.
Colonisation is a completely different question/goal to sending humans to Mars.
>> Is it? Why?
> Well, if we get a self-sufficient mars colony up, nuking ourselves will become survivable.
Along with releasing an eco-system ravaging engineered biological organism. Or nanotechnology. Or AI. Or getting a bad luck roll with an asteroid. Or climate change blowing past a tipping point. Or something that I have no concept of anymore than an individual circa-1900 would understand the concerns of today.
Why?
Because we owe it to the !$%^ing universe to safeguard our (as near as we can tell) incredibly rare existence.
You know what happened to all those species that said "This planet is good enough?" Something bad happened. 1,000 years; 10,000 years; 100,000 years; at some point. And... poof... have fun starting another 3.5 billion year slog back to us.
Disclaimer: I don't think "us" is necessarily the pinnacle of evolution, but I tend to feel we're special enough to save another 3.5 billion years of history on recreating.
Also, even with the worst kind of nuclear war we can imagine, the number of people still clinging to the edge of survival on, say, New Zealand will easily surpass the biggest Martian colony we can optimistically imagine for the next 300 years.
So, if we're really that worried about our survival as a species, build a nuclear bunker in New Zealand. Actually, build one in every nation on earth. I'll bet it will be still cheaper than going to Mars.
Going to Mars is "cool", and I do want to see it in my lifetime, but treating it as some kind of insurance for mankind just doesn't make sense.
The Moon is much closer and you're facing similar problems - low gravity and virtually no atmosphere or no atmosphere. At the same time you eliminate the long trips that would complicate Mars colonization.
Mars has no air. That's downside.
But there's no snow to block your roads and no rain to turn them to mud. Then there's no permafrost to make ground undiggable. That's tremendous upside for e.g. mining operations.
There's no rivers, lakes or forests. There's probably some rough terrain and canyons, but you may build bridges that'll last long.
Whatever you build on Mars, stays on Mars. Whatever you build in the far north, detoriates rapidly.
You're right. As the article mentioned though, the public doesn't like the idea of leaving someone on an alien planet, and the public isn't rational.
One might almost say, "especially under worst-case climate change scenarios".
It’s such an astonishing accomplishment to build something so lightweight, so complex, so versatile in such a short amount of time. It’s astonishing that it came together at all. And worked! Every single time, even beyond what it was originally intended for (during Apollo 13).
A hypothetical MAV would have a similar role during a Mars trip. Be this complex yet lightweight and versatile little thing, a rocket that can take off from another planet without all the fancy infrastructure we have on Earth. (Luckily Mars has still relatively low gravity. Imagine trying to take off from Venus with it’s atmosphere and Earth gravity and think of all the stuff we need on Earth to pull that off.)
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The MAV will have to do all that and a lot more besides, and in a much bigger gravity well, and with an atmosphere, and for a multi-year period in an incredibly hostile, dusty environment.
EDIT: Actually, I had a favorite - the F1 engine. I find the idea of needing an auxiliary gas generator rocket engine inside just to turn a fuel pump pretty amazing. Likely I'm a bit more impressed by raw power than you :)
I'm also fairly certain they're already quite knowledgeable regarding the effects of weak gravity on the human body.
I suppose we just don't have enough data to say one way or the other.
Edit: an old Nasa article on the topic...
http://science.nasa.gov/science-news/science-at-nasa/2001/as...
So much Earth infrastructure we depend on for this stuff.
Why would you need to do that? Why not land the Falcon (Edit: Actually, it might be a Raptor) with the Dragon already on top of it?
It's not even designed to stay in LEO, they go out of the way to make sure it falls back into earth's atmosphere within a orbit or two (often less than a single orbit).
You want to design a new craft from the ground up with the job ascending from mars. Ideally to save weight you want the stage's rockets to be used as many times as possible: Mars ascent, Mars Landing, Potentially orbital manoeuvres to get from LEO to mars and maybe the final part of earth ascent.
But making a rocket fire that many times requires the ability to refuel, perhaps even twice (both LEO and on mars). You also have to be confidant about re-igniting the engine that many times over 5+ years.
Going even further, if a combined descent/ascent vehicle could bring down empty fuel tanks, the fuel making equipment could stay on mars and make fuel to supply the next mission.
Is that the only problem? What about boil off? They don't touch that at all.
EDIT: They do talk about boil off while being manufactured on mars, but not in transit.
43 hours, standing up, no food, no toilet, no sitting down, no stretching your limbs. Riding on top of a metal rocket. Surrounded by millions of miles of lethal void.
It's the pre-flight checks which will make the lack of seats a large issue, they need to be at the MAV at least 4 hours before launch and have the doors closed maybe an hour before takeoff (before that anyone not doing checks could sit in the rover)
I would have to agree, though once in orbit the standing up/sitting down thing doesn't matter as much as the stretching. I don't imagine the rest would bother the crew that much, as they had to deal with it just to get to Mars in the first place.
I fear that for as long as we un-necessarily bind ourselves to limited and massive chemical propellants, rocketry will remain forever an inefficient and expensive business. I fear our dreams of our future in space died with nuclear propulsion.
Thermal nuclear rockets would be compact and could fuel up with pretty much any old crap, be it hydrogen, methane, co2, so long as it can be made cryonic and heated by fission to blast out of a nozzle. Irradiation can be made a not-huge problem by using shielded heat-exchangers. Adds mass, but not as much mass as solid or liquid fuels and oxidisers.
Nuclear pulse propulsion is a more controversial proposition as it typically involves significantly irradiating wherever you go, but if you're dealing with non-atmospheric bodies, or bodies so utterly inhospitable that irradiating them isn't going to make a jot of difference, again, why not?
Well, the why not commonly given is that if you lose a chemical rocket carrying a nuclear reactor you have a scope for fallout on earth, but then again, we fly RTGs, and if there aren't spaceborne nuclear launch platforms I'll eat my hat.
Anyway. I really wish we would be brave enough to experiment with new tech, rather than incrementally improving existing tech. The horse is better than it was, to be sure, but it's still a horse.
Some articles on this stuff if anyone fancies getting lost in a wiki-hole:
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
https://en.wikipedia.org/wiki/Project_Pluto (holy nuclear ramjet, batman)
Progression of nuclear thermal rockets:
https://en.wikipedia.org/wiki/Project_Rover
The other thing is that we can get to Mars with chemical rockets. Using an NTR wouldn't make the journey meaningfully faster - we'd just bring a larger payload - and while I'm sure that almost everyone would rather triple engine Isp, personally I'd rather just go to Mars already instead of waiting for another couple decades.
If we do start spreading out into space, the vast majority of our early trips will be to the moon or to Mars. Don't overengineer the problem - an cheap and adequate rocket now is better than an excellent rocket later.