The Shape of a Mars Mission
idlewords.com
idlewords.com
It really puts the frustration I have with Musk's constant "we're going to Mars" in context. Yes, a big rocket is necessary prerequisite for Mars. No, it is not the only problem you need to solve.
And also having worked with the reality of human spaceflight operations, we are just not ready yet to send a spacecraft into deep space for months on end. It's easy to throw out blithe statements that we "just need a big spaceship", or we'll use ion drives or some other such tech, but the reality is way more messy than that. We just aren't ready yet and we won't be for some time.
Time between resupply? Well, you can just take a bunch of resupply missions with you. Most stuff is packed ahead of time, except fresh veggies and fruits, but deep freezers can keep the nutritional value of those nearly as well as being fresh.
Redundancy/reliability? Bring the spare pool with you instead of keeping it on the surface for resupply flights. Bring two different systems.
Long duration life support? Enough mass allows you to avoid it all together if you like. This still has not sunk in to most of the fairly educated people who opine on this topic. Simple life support systems are VERY reliable, and the advantage of advanced life support systems is they reduce mass. If you don’t need the mass reduction, you don’t need the advanced life support.
Far from medical care? Small crew sizes are a mass constraint. More mass means you can afford large crews with dedicated medical personnel. And the equipment to go allow with it.
Also applies to radiation shielding (mass) and even partial gravity (centrifugal gravity is well known as a replacement but for some inexplicable reason is avoided… and yea, even short arm centrifuge is useful and could be used on the surface… the disorienting effects are actually manageable, and while in space, a tether can be used to enable long arm centrifugal gravity with little Coriolis effect).
Transit times can also be reduced significantly with refueling. 80-120 day transits are feasible, not just the most efficient 150-210 day transits for long stay. The surface of Mars also has significant radiation shielding in spite of the thin atmosphere. The Mars rover Curiosity measures the same radiation equivalent on Mars’s surface as on ISS today. Mars rover Perseverance also demonstrated production of unlimited oxygen from the Martian CO2 atmosphere using electricity. Regolith could also be used to enhance radiation shielding. This is before discussing water mining (and even that can be done without touching regolith, just the air using the WAVAR technique… useful for crew consumption although this method doesn’t scale up to producing enough for propellant very well).
There is no a single hazard or obstacle to a Mars mission that isn’t at least partially mitigated by having a lot more mass capability, ie a big and cheap reusable rocket (capable of landing on Mars and aerobraking).
Since it's not plausible that you could bring anything back from Mars that would be worth enough to make colonization practical from the perspective of Earth, Mars colonists would always have to assume that the last rocket that was launched is the last that will arrive. From their point of view, they'd want to be able to manufacture absolutely everything locally as soon as possible.
It's one thing to say "we can make unlimited oxygen from the soil never mind the atmosphere", it's another to find a source of nitrogen or other inert gas that makes it possible to live in an atmosphere that doesn't make everything into a firetrap. It's one thing to spin the kind of science fiction that Gerard K. O'Neill did, but his disciple Eric Drexler realized just how bad the problem of 'advanced manufacturing' is and went off to follow his own El Dorado, writing a fascinating book [1] about a class of systems that 'just don't work' [2]
Not to say that the goal of "a population of 10,000 people being able to make everything that 8,000,000,000 can make" is unattainable, even if we can get it down to an advanced industrial base being supported by 10,000,000 people it would be a game-changer here on Earth. I can see paths there, but it's by no means a bird in the hand.
[1] https://www.amazon.com/Nanosystems-P-K-Eric-Drexler/dp/04715...
[2] https://latecomermag.com/article/what-happened-to-molecular-...
And I agree 10,000 is far too small for self sustaining settlement. A million is the minimum. Even 10 million would be a challenge.
That said, throwing more money and gear against the problem will likely be the way to go. Besides, it doesn't actually have to be done all in one go, if the vision of SpaceX is that of mass production, they can launch a whole chain of Spaceship sized payloads towards Mars years before a human crew is sent that way, giving them supplies and whatnot on the way, in orbit, and on the surface. That'll require a lot of planning and automation though.
Had we maintained the political will though there's no real reason we wouldn't have had a colony on Mars decades ago.
We do not have any examples of space orne and isolated systems supporting human life for months, especially beyond the magnetosphere.
Providing food and other necessary resources for a long stay would not be especially difficult, but there's no need for it, and that leaves more volume to store other stuff.
The ISS, despite being a 'station', is very small with a pressurized volume of about 900m^3, about 100m^3 less than Starship. The linked capsule design also means the real usable volume is substantially less.
They know darn well that we're simply not ready to sail into deep space. Radiation shielding, orbital manufacturing, computer autonomy, peaceful nuclear use, etc. Lots of needed hypothetical technologies, or requisite trust and social stability that allows for the use of those technologies are missing. They couldn't even get to work on it in some of domains.
We in the public all knew about that wall by the 1980s: the anime Mobile Suit Gundam(1979) literally begins with a space habitat declaring independence and creating a Bay of Sydney in Australia by gassing and throwing down a resisting habitat with a reverse swing-by at the back of the Moon. It's all overblown plot for a work of fiction, but also something everyone knows will happen eventually that no one has response strategies for.
So as the immediate "path forward", NASA put up a boathouse next to a small lake near the ocean under the pretense that long-term researches of effects of lakewater on human body are to be conducted, using surplus Russian cargo ships. We know what happens if we did row into the ocean with the boats we have or can launch from Earth, we die from radiation. They're not conducting researches, they're just trying to keep the boat makers alive until we sort out the trust problem needed to work on the work to follow.
Not a lot had changed on that front in the past few decades, other than that the aforementioned weak trust had started collapsing very recently. No way the world is going to trust the US with NERVAs and Lunar shipyards under the current circumstance.
And yet Mars is the next logical step - not the Moon. The Moon's total lack of atmosphere, lower gravity and extremely long day, coupled with its pesky regolith make it an environment far harsher than Mars IMHO. Worried about the cold on Mars? Think again - lunar night is equally cold, and it lasts two weeks. During that period, human survival depends on two weeks of continuous heating power.
A night out watching some meteor shower in August? Think again - by staying outside on the Moon, you're taking a gamble with meteorites, and it's not just "at night" - it's all the time.
https://mooncampchallenge.org/meteors-on-the-moon-sunny-with...
To live on the Moon or beyond, you need a proper ship, and steel shipping containers with bathroom tiles, aren't. Those are at best boats to carry people to the ship, at worst cargo sacks. Not the ship. The ship has to be "radiotight", so to speak, and for that, they have to be built in low- or microgravity.
And that raises the question of politics: the world is not only ready to handle megaton sized ships on orbit responsibly, but moving away from such maturity fast.
We are in fact far more ready for sending crewed missions to Mars than we were to sending crewed missions to the Moon when JFK made his Moon speech. We had only barely launched an astronaut on a suborbital flight at that time! And yet 7 years later…
I'm confident that if they tried to launch a Mars mission with current-day technology now, the crew wouldn't make it. Nobody's ever been in space for that long, to start - yet Musk wants to deorbit the ISS, the only viable platform at the moment to even try and simulate a two year space trip.
The annoying thing is that we could’ve been simulating long duration partial gravity using artificial gravity for decades, but NASA has refused to do so. For inexplicable reasons. If I had to guess, it’s due to the microgravity research community fiefdoms who have made a career of microgravity health effects and so don’t like the idea of directly addressing them using artificial gravity as it makes a whole career’s worth of work largely obsolete.
Not if you want it dependable enough to entrust a multi billion dollar project and several people’s lives to it.
People talk about the moon mission like some massive conquest of space, but we needed to get the fuck off the moon much past sunrise or astronauts would have cooked. It was based on extremely limited oxygen supplies and involved significant radiation exposure that was only ok because again we ran away from an extremely inhospitable environment before things went wrong.
Even today the ISS benefits from earths magnetic field, its space light not a true replica of a mars mission.
The biggest problem is that people have really lost the ability to think big. There's always infinite reasons to not do something, and there will never be a perfect time. So at some point you simply have to choose to push forward. Like Kennedy put it:
"We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too."
Talk about hyperbole.
The moon mission has been prepared for before that speech took place. It wasn’t just starting from scratch and hitting the moon in 7 years, instead the speech was more public disclosure of a deadline that looked achievable but would hit after his presidency (1960 + 8 being less than before the decade is out: 1970).
The biggest problem is we already did the easy stuff. Playing tag with the moon is unbelievably easier than a permanent moon base or landing on Mars and getting back to earth.
Saying we'd be on the Moon in 7 years was not something that looked achievable except to the most fanatical of enthusiasts. To the average layman it would have sounded no less impossible than me saying we'll have a man on Mars in 7 years from today. And landing on Mars in many ways will be much easier than the Moon. Not only is the terrain broadly more hospitable, but you have an atmosphere to enable aerobraking which simplifies both landing and braking and enables various options (like some sort of parachute staging or backup). The biggest and really only complexity with Mars is its distance. Outside of that it's easy mode.
That’s a meaningless yardstick here. People at NASA definitely thought hitting that target was achievable before the speech.
> Landing on Mars
Landing isn’t the issue. Get people there alive and having enough deltaV to get back is.
It was a mission they dedicated themselves to, and humans have this way of making things happen when we actually set our minds to tasks. A reality that's often been lost in modern times as we have mostly moved away from pursuing, let alone achieving, great things in the real world. One of the many reasons to get humans on Mars.
[1] - https://ntrs.nasa.gov/api/citations/20190002249/downloads/20...
The Apollo missions got unbelievably lucky in that none catastrophically failed despite multiple close calls. However, if you’re willing to try multiple times the odds any mission being successful is much better than every mission being successful.
IE: Six missions landed on the moon. If they each had independent 50% odds then six heads is a long way from impossible ~1.6%, but at least 1 head is quite likely ~98.4%. I doubt we would have tried for a 6th mission after 5 failures in a row, but the point is definitions of success matter a great deal here.
Similarly failures improve odds of success in the future because you learn from mistakes and success means the system is functional eliminating some risks.
On that specific launch, which is another way of saying they believed the project had a very good chance of having someone walking on the moon. Failure there wouldn’t even mean people died, just that they didn’t walk on the moon and then safely get back on that mission.
Had the Apollo missions failed you would obviously be arguing, using the exact same data, that they 'knew they never had a chance.'
No, an earlier post argued that 6 successes doesn’t mean the odds of success on every mission was high. “Got unbelievably lucky” https://news.ycombinator.com/item?id=43130343
The exact opposite position after 6 failures would be that the odds were good that at least 1 mission would have succeeded.
Obviously, things aren’t actually completely independent, but 6 lunar landings could have successfully been completed with a huge range of different odds. 50% odds of success on the first launch isn’t inconsistent with 6 successful launches or 6 failures, it’s just not enough data to really narrow things down.
Again, I’m addressing the point “getting them there alive”. Unquestionably, we know how to get crew to Mars alive, and even for the full mission duration, radiation isn’t even in the top 10 of the hazards that could actually kill them during the mission. (It’s a long term hazard, comparable to lung cancer if you’re a cigarette smoker.)
It’s possible people spending significant time on the surface of mars would recover, but that’s more speculation than proven.
Going beyond that is not really meaningful since that's far longer than any normal transit to or from Mars, which is the immediate target.
Living on mars at 38% earths gravity is believed to make things worse over time, so no you can’t just consider transit times independently. On arrival they would likely be fine inside a habitat. But trying to walk around in an Apollo 11 era 180 lb pressure suit in 38% gravity would be nearly as strenuous as walking around on earth and we’d like them to be able to work not just take a few steps and sit down. It’s possible to reduce that weight, but needing to carry oxygen tanks means there’s quickly a tradeoff between lighter weight and less time outside.
Now, for an extremely brief touch Mars and come back while burning a huge amount of fuel to make a shorter trip sure they’ll survive. But start talking a 3 year mission and things don’t look good.
Back on Mars they'll be able to quickly regain their motor skills coordination, as well as strength/bone density. So it will be effectively equivalent to Earth in this regard - actually it will be even better than Earth because the reduced gravity will probably send the overall adjustment time down from a couple of days to a couple of hours, especially with a normal duration transit.
> stuck on the ISS for going on 9 months now
Stick right next to earth and all the medical care they would want on landing. That’s the difference they don’t need to be functional on earth.
> regain motor skills and coordinate
Meaning they’re nearly helpless for a significant period on landing. That’s a massive safety concern and limitation on mission profile.
> as well as strength/bone density
There’s serious concern around retaining let along regaining bone density on Mars. 38% g isn’t a well studied environment here but it’s a long way from earth and likely to result in significant bone loss up to a point. Meaning their trip back is now significantly more risky.
Note that the magnetic field only deflects lower energy galactic cosmic rays which have a lower gyro radius than the real whoppers. The magnetic field is less important to overall radiation shielding than the earth’s atmosphere.
On a long-stay Mars mission, that adds up to 12-18 times the accumulated GCR exposure compared to a six-month ISS increment.
In fact, look at Table 2. It shows that at ISS, the dose from the SAA is about the same as the GCR dose, so by ignoring trapped radiation, you’re manipulating the result by a factor of 2.
The mention of "quality factor" here just begs the question. The reason we need research on biological effects of high-Z ion exposure is that it has a different mechanism of damage, not captured by that paradigm.
With the current worldwide ageing demographics, it would have the added benefit of providing an awesome feat to inspire seniors across the world to not go gentle into that good night, showing old age should burn and rave at close of day.
A hypothetical 500 day mars mission is ~1 Sv optimistically which is something like 5% fatal cancer risk. A 3 year mission you’re well above that even before considering solar storms etc.
I think many would sign up for a mars mission especially as treatment improves, but there’s only so much wiggle room here.
> you’d be developing new technology all along the way
Aerospace does not work like this. Hardware does not evolve until launch, it is frozen in time to allow for testing and flight qualification for subsystems, and systems as a whole.
The track record for successfully landing on Mars isn't that awesome:
> Historically, counting all missions by all countries, there has been about a 50% success rate at Mars — and the odds of successfully landing on Mars are only about 1 in 3.
People who don't normally follow space may be confused by recent things re: Starship because the media is being intentionally deceptive, as usual. These are not normal flights. They are purely experimental flights, mostly expected to fail, to gradually work the kinks out of the system. It's the difference between hitting compile and launching something to production.
When JFK made the speech, it was in the middle if the cold war and there was a realistic fear that the "capitalist way if life" could be beaten by command economics of the Soviet Union in cutting edge science and rocketry, justifying the huge amounts invested in the space race. What is the impetus now? We're all about government efficiency in cutting the social-safety nets, scientific research, but we'll carve out a Mars mission "because it's hard"?
Which political order are we in an existential battle against; Russian-style oligarchy or or Chinese-style state-controlled capitalism? It appears we're losing on both those fronts, any "space race" to Mars would further emphasize the point, AFAIAC.
Not to mention launching to Mars from the moon is easier (in some respects, not all).
A Moon base will be a far harsher place than a Mars base. Mars is bizarrely similar to Earth - nearly the same length of day/night, similar axial tilt so similar seasonal patterns, nearly the exact same land area, and even calm weather. Notably the 'raging dust storm' in "The Martian" that was used to set up the crisis for the movie was one of the few things that was intentionally faked. The low atmospheric pressure on Mars means even the most brutal dust storm would feel like a slight breeze at most. It's also telling when you need to fake something to create a crisis, in an otherwise very hard sci-fi book!
To be fair, the vacuum on the moon is also not comparable to the windy atmosphere on Mars.
The second is because the ISS is quite tiny. It has a total compressed volume of ~900m^3 contrasted against the 1000m^3 on Starship. Factor in its design of interconnected pods and the usable volume sharply decreases.
2) Partial gravity
I do see Trumps side, that if they take decades to get anything done, maybe the project should be scrapped. But space-x has proven they can launch rockets reliably and cheaply, I believe we should use their innovation but to the moon before the red planet.
Designing a mission involving 1000 days in space with no prospect of resupply is the hard bit. And it's the likes of ESA and NASA that have visibly been spending money on research and testing for that bit, not the very successful private launch vehicle supplier and LEO constellation operator.
Just like invention of the rocket engine enabled all kinds of rockets, the ability of having a lot of payload available for the mission enables all kinds of solutions for existing problems. Robotbeat is correct.
This is just the latest version of The Music Man and Marge vs. the Monorail.
Musk is serious about getting rich but not about going to Mars. It's always been a ploy to trick naive tech nerds into sacrificing themselves for the goal of "saving the world".
Tesla is a perfect example of this. A low-cost no-frills electric car would do a lot more for the environment than the vehicles produced by Tesla, which are luxury-priced and continue to (falsely) promise "Full Self Driving". The market is obvious: well-off tech nerds who are made to feel good about themselves that their luxury purchase, with cool technology, is "saving the Earth". (A similar strategy is used by Apple, by the way. Apple convinces people that buying a new iPhone every year or few years is "carbon neutral" and that it's somehow ok to eschew device repairability, upgradability, user battery replacement, etc.) We're told that the plan was to sell cheaper Teslas "later". It's always later. Yet other auto manufacturers have produced cheaper electric vehicles without the self-driving crap, and still for Tesla it's "later". So Musk has $44 billion to spend on Twitter but not on taking lower margins on Tesla vehicles?
We're told now, by Musk, that the biggest barrier to the Mars project is not, say, the gravity on Mars, or the radiation, but rather "the woke mind virus". Uh huh. Con man.
I'm not denying Musk's accomplishments, any more than I'm denying that Trump managed to get himself elected POTUS twice. But they're both con men, and their real goals—power, self-enrichment, self-aggrandizement—have never been the same as what they tell to their followers. They're surely among the best con men on the planet. It feels like all of the top con men are coming together now for the big heist, like Ocean's Eleven.
Any stage in making a mars trip viable is a multi-billion dollar project. Actually arriving on or around mars has no value in itself other than the achievement and some science, but the runup will possibly make SpaceX the wealthiest company in the world. Or at least pull tens, hundreds of billions out of the US economy.
And most of NASA's budget is not spent doing stuff, but on thinly veiled graft like the SLS which obviously will not be redirected to SpaceX because the goal isn't to achieve anything, but to spend money on interests tied to the people directing the spending.
Just because they're doing fine now, doesn't mean we want to give SpaceX a monopoly in the future.
Reminder: SpaceX was not a thing a few years ago, and NASA throwing money at them could have been considered 'wasteful' when there was a solution that worked already. We are where we are now because the government spread the money around a bit: some of those 'bets' worked out, some did not.
All that aside, I actually agree with you in principle! The SpaceX of tomorrow will not necessarily be the SpaceX of today. And having a space economy full of good healthy competition is a great thing for everybody, including SpaceX. But this was not a case of that. This was just an old dysfunctional company relying on some old corrupt politicians to butter some bellies.
It makes lots of sense to torch a crowded market & lean-in on heavy-lift first-mover advantage. He will be the only contractor for a hypothetical Mars missions and will have a blank check as soon as the government commits to it - if he doesn't write the bill himself.
SpaceX will lap Blue Origin on heavy lift, while having NASA pay for R&D that will be used by SpaceX to go the asteroid belt and mine precious metals or whatever post-Mars yarn will be spun to make SpaceX a trillion-dollar company, realistic or not.
From Musk's perspective, NASA is an unnecessary, inconvenient middleman. Eliminate the public middleman, and everything goes to private companies, in other words, to SpaceX. And it's not just about NASA; the current administration wants to privatize the entire government, including the US Postal Service, for example.
> And most of NASA's budget is not spent doing stuff, but on thinly veiled graft like the SLS which obviously will not be redirected to SpaceX because the goal isn't to achieve anything, but to spend money on interests tied to the people directing the spending.
Musk/DOGE currently controls all federal spending.
Even getting all cars to be hybrids would be a huge win (either parallel or series / range-extended).`
The proof will be robotaxis in Austin this June. I hope to be able to send my Tesla out to be an Uber to earn money when I sleep sometime late this year or next. Time will tell but we do have re-usable first stages and Starlink already and it is pretty great.
Maybe Musk has no interest in getting humans to Mars, but if this con man builds a rocket that gets cost to orbit in the $10/kg, con me some more please.
Most cons would be great opportunities if they followed through, the problem is the "having no realistic path to following through" part
Starship is already well on its way to succeeding, in the big picture
The reason nobody is able to compete because it takes lot of capital to bring new technology in market. If you cannot hire the best people you will not get the best technology. And no engineer wants to work at a company at pays less.
More profit buffers company from random market events.
We live in a capitalist society. Tesla/Apple are just a by product of the system.
Also, whatever Elon says is should be taken with a grain of salt. He is a salesmen. Hyping stuff up so that people buy.
I didn't say there was. But there is a problem in lying to people, claiming that your goal is to "save the US" or "save the Earth" or "colonize Mars" when it's really profit maximization.
> Also, whatever Elon says is should be taken with a grain of salt. He is a salesmen. Hyping stuff up so that people buy.
Exactly my point.
You can think of flying to Mars like one of those art films where the director has to shoot the movie in a single take. Even if no scene is especially challenging, the requirement that everything go right sequentially, with no way to pause or reshoot, means that even small risks become unacceptable in the aggregate.
It just doesn't make sense to me to send humans. Exhaust the science collection of robots first.
I would like people to start a civilization on Mars. I would like to go to Mars. I will pay for the privilege to do so or see it happen for othera. Maybe it will. There are many people like me.
The fundamental problem is that moving parts break. This results in things like rovers being exceptionally conservative in both their design and behavior, out of necessity. For instance Curiosity's drill can only drill to about 6cm, and even then it broke after 7 limited activations, which then took a team of scientists 2 years to come up with a partially effective workaround. A guy on the scene could have fixed it a few minutes, or done just as effective 'drilling' himself with a spoon. We're literally not even scratching the surface of what Mars has to offer.
Another issue is in mobility. That involves lots of moving parts. So Curiosity tends to move around at about 0.018 mph (0.03 km/h) meaning at its average speed it'd take about 2.5 days to travel a mile. But of course that's extremely risky since you really need to make sure you don't bump into a pebble or head into a low value area. So you want human feedback on a ~40 minute round trip total latency on a low bandwidth connection - while accounting for normal working hours on Earth. So in practice Curiosity has traveled a total of just a bit more than 1 mile per year. And as might be expected its tires have also, broken. So it's contemporary travel time would be even worse.
Imagine trying to dig into all the secrets of Earth by traveling around at 1 mile per year, and once every few years (on average) being able to drill hopefully up to 6cm. And all of these things btw are bleeding edge relative to the past. The issue of moving parts break is just an unsolvable issue for now and for anytime in the foreseeable future.
----------
Beyond all of this, manned spaceflight is inspiring, extremely inspiring. Putting a man on the Moon inspired an entire generation to science and achievement. The same will be true with the first man on Mars. NASA tried to tap into this with their helicopter drone on Mars but people just don't really care about rovers, drones, and probes. It'd be nice to live in a world where kids don't aspire to be friggin streamers when they grow up.
We can't be so sure. The probes have discovered that Mars has no channels and vegetation. That water is uncommon (then discovered that it is still there in some quantity). They found out precise atmospheric composition, mapped out all major surface features, observed the climate over decades. They discovered perchlorate toxicity of the soil for humans, something that would have been a nasty surprise to a manned crew.
Am not opposed to Mars expeditions in principle, it's an exciting thought. But I just can't see humans contributing all that much on the odd few landings, with a high chance of contaminating whatever traces of life there could be.
Of course though you're completely right that mapping out the rough surface and climatic patterns is critical, but that would have been capable with the first probe to Mars - launched some 53 years ago. There's just really extreme diminishing returns with probes and rovers. For instance these [1] are NASA's highlights for what Perseverance, the latest Mars rover, has achieved in 4 years. To call them uninspiring would be an understatement.
[1] - https://science.nasa.gov/mission/mars-2020-perseverance/scie...
If you read the article, you'll see that these are things that we can't realistically do with humans anytime in the foreseeable future.
I do not, in general, find the article compelling in the least, but it spawned some interesting discussion!
https://www.investmets.com/nasa-workshops-aim-to-merge-on-an...
So do human bodies, and the extensive life support systems they would depend on in space, which I think was the theme, more than anything, of this particular article.
The only unique think I can personally add here that we're probably a lot more comfortable with high failure rates for machines than even low rates of failure for humans.
According to Internet searches, Starship can bright 100 tons to Mars surface.
A common large Earth backhoe seem to weight 20 tons, so with Starship you can just ship one and it will be capable of driving at normal speeds (up to 100km/h), excavating for meters and not centimeters, etc.
(obviously it would need adaptations since diesel engines need air that isn't present on Mars and EV batteries might have problems with the cold, but it would be a similar weight magnitude)
These issues are why things that act like really poor performing go-karts with a few gizmos attached end up costing billions of dollars and taking years to develop and finally manufacture.
If you had a budget for one human mission, or a dozen new robots every two years, which one would you consider more beneficial?
Robots will make a lot more progress in the next decades than humans will.
Also, it if takes us 50 years to send humans to Mars vs sending a constant stream of improving robots now, then robots win.
[1] https://databank.worldbank.org/metadataglossary/world-develo...
starting anything by throwing out the value human life seems like a bad direction.
When we went to the Moon, the obituary for the astronauts was written before they even took off. And the astronauts themselves felt they had somewhere from a 50% to 70% chance of success. Everybody was well aware of the extreme risks, but they still voluntarily participated, because they felt the achievement was worth the risk. And indeed those brave men inspired an entire generation to science and achieved what many believe was still the greatest achievement in humanity's entire history.
The first missions to Mars will always be high risk, because the fundamental issue is that you're always going to be doing a bunch of things that no other human ever has. There's just so many unknown unknowns there that we're going end up getting surprised by something. So all we can do is make sure we have highly capable people and try to prepare as well as we can. But in the end, even when you work to minimize risk as much as you possibly can, that mission will always qualify as 'risky.'
The actual failure analysis and engineering was substantially more confident, because otherwise why go? 50% is a coin-flip, but those odds were already proven wrong by the missions before Apollo 11 anyway (since there was more then 1).
Of course there were working assessments internally and they generally put the figure at about 50%. That figure is from Gene Krantz's excellent book "Failure Is Not an Option." The reason you go is because you cannot find any other practical way to significantly reduce the risk, and are willing to accept the risk you end up with.
Also I feel you're somewhat denigrating the astronauts with your comment by saying their estimations weren't "real". These weren't just adrenaline junkies looking for a wild ride - they were extreme intellectual outliers with higher degrees in aerospace engineering and extensive backgrounds in the development and application/flight of all sorts of aerospace systems. Like that paper also mentions, "The only possible explanation for the astonishing success [of the Apollo Program] – no losses in space and on time – was that every participant at every level in every area far exceeded the norm of human capabilities."
[1] - https://ntrs.nasa.gov/api/citations/20190002249/downloads/20...
Space: the final frontier. These are the continuing voyages of the starship Enterprise. Their ongoing mission: to explore strange new worlds; to seek out new lifeforms and new civilizations; to boldly go where no man has gone before
You missed the 'volunteer' part it seems. People have volunteered for expeditions with uncertain outcomes since, well, forever. Some people do their utmost best to tempt fate by climbing skyscrapers and masts without any safety devices, they jump off cliffs in clothing which gives them a slight advantage over gravity, they get into devices which are supposed to keep them alive at depths which would crush them to ¼ of their size if they were to be exposed and more. People used to embark on sailing vessels to trek to unknown places, a practice which started when sailing vessels became a thing. People want to explore frontiers and some people are willing to take great risk to be among the first to do so.
No silly quote from a Hollywood production will keep them from following their drive to boldly go where no man has gone before. Or woman, for that matter.
“Robots explore Mars” is a daily news highlight.
“First humans land on Mars” is a global historical event.
The trip to the Moon was a free trip to Jurassic Park in comparison.
We are self-healing, regenerating, low-power, versatile, autonomous, and most of us have a pretty decent array of sensors built-in, along with some communications equipment that's capable of interpreting the signals from our sensors and transmitting that information to other humans in a remarkable variety of ways. All of these are approximate and relative of course, if someone replies with e.g., "but actually we're not as low power as...", it will be easy to ignore.
Specialized machines can do things humans can't, of course. No single human could have survived as long in the Martian environment as any of the rovers have.
But nobody has yet designed a machine that can do all the things humans can do.
Take the single problem of mobility: many very smart engineers have worked together to develop a set of wheels that can usually move the rovers around their environment without getting stuck or damaged, or at least have a chance of getting unstuck. A human that hasn't climbed a set of stairs in a decade can still outpace the rovers, and do so over more varied terrain, and with less chance of getting stuck.
So, yes, from an engineering point of view, building new robots that can do things and shipping them to Mars to do those things presents a lot of very interesting technical challenges to solve. It's all endless puzzles and little unsung feats of science and engineering -- assuming there is a country left with both the will and the resources and the talent to pursue such things.
But from a human exploration perspective -- our instinctive drive, or compulsion, or whatever it is, that has spread our species across the entire planet -- no machine will ever quite satisfy the desire to have that experience with the sensors we were born with.
My enthusiasm for a human mission to Mars has waned quite a bit in the last few years, largely owing to its most vocal advocate. Still, all the same, I think we should acknowledge that robots are poor substitutes for geologists.
The trouble is space itself is really rough in new and different ways. Even if everything is going right, the radiation is extremely dangerous, both on the journey and on Mars itself. And there's bone decalcification which happens very fast. And life support systems issues become very quickly entangled with all the other engineering issues that can cause cascading failures between systems, so even if you didn't think of (say) engineering failures of how power gets to some component as a life support issue, it can become one due to the interdependence of systems.
Yeah, we’ve got great fine motor skills and high dexterity, but are obviously still too dumb to emulate those parts effectively.
Also, we didn't "send" them, the early explorers and bases were done by people who wanted to go and do research there. We have lots of people who want to go to Mars to do research or who want very much to benefit from the research humans can do better on Mars than current robots.
What's the timeline on "exhausting all the science collection abilities of robots?" Ten years? Fifteen? There are a lot of potential future robot abilities...
If you think robots should do everything then you might as well retire the human race. Why even bother to live. Why explore the stars when you can get a robot to do it for you?
That's a serious paradigm shift compared to what this (excellent) article describes.
This is a big part of their obsession with lowering costs to space. When the launch costs are not such a huge economic factor, you have much greater leverage with doing things like building, resupplying, or even engaging in interplanetary commerce.
Going to Mars may have been part of the story, but I doubt that it was a strong component of the decision making in the end.
So the most logical place to start for this sort of 'humanity guarantee' would be Mars, which shares an oddly large amount in common with Earth. There's a verbose (and rather entertaining read) with lots of first party commentary here. [1]
[1] - https://waitbutwhy.com/2015/05/elon-musk-introduction.html
This article is however very useful to bring pragmatism to the discussion.
Maybe the best insurance for humankind is to start shipping a continuous stream of robots to Mars to prepare human landing in many (many) years.
Worrying about the atmosphere stripping away is akin to worrying about the smaller of Mars two moons being on a path that will impact in 100,000+ years with the surface of mars.
In many problem domains mars is an easier target for long term habitation than the moon, the biggest challenge is getting there. The retorts from people here about farming miss that we don't need 'soil' to farm, there are techniques that mostly just need water and vitamins that can dissolve into it. At Epcot they have a system to breed fish and use the fish waste for feeding plants to grow. Throw in mycelium for handling human waste and you have an efficient system for augmenting food production.
A serious effort for mars will have as many or more spinoff technologies as Apollo gave us. The computers we are using today are further along in development from the massive influx of effort to make computers that could fit in space capsules. With the acidification we are causing in the ocean, a reliable way of converting C02 to oxygen at scale might be needed here on earth to prevent an oxygen collapse within decades. Climate change is a bitch, and it could give an excuse to start charging people for breathable air here on earth so the cynics may be right about that eventually happening. That possible disaster just isn't on even most climate scientist radars yet.
There will be other spinoff technologies we just don't see yet. The large rocketry needed to get there also opens up resource extraction from near earth objects. There's massive material wealth just barely outside our present grasp. It would be nice for materials like platinum and gold to follow in the footsteps of aluminum in becoming common enough to be usable for trivial items. Aluminum was a precious metal just a few hundred years ago in its refined form. Gold nanoparticles look like a candidate that could make current GLP-1 drugs obsolete, it works in animal studies but not tested in humans yet. Manufacturing in space is also on the verge of practicality. Metal foams, ultra low attenuation glass and optically transparent aerogels can be made in microgravity that are superior to the versions that can be made here on earth. Metal foams would be ideal for making ships, cars and planes that are much lower weight than we can make now without loss of strength, less weight means fewer watts per mile and less material needed.
The people whining about the idea always seem to miss the secondary effects of making the effort and always see to paint the optimistic take as naive, really they are just demonstrating short sighted thinking.
If that happened Earth itself would still, even during the extinction event, be a dramatically more pleasant place than Mars. But nonetheless that event would kill off the overwhelming majority of people on Earth, and very possibly 100%, because it's such a significant change from the status quo we expect to continue on Earth. But having a parallel society or societies would ensure that even in the 100% scenario, life could get back up and organized relatively quickly. And even in the "only" 99% of people killed scenario, the outside help could help to reestablish order and kickstart society.
How though? Not in terms of engineering, but in terms of politics and economics. The biggest charter city in the world just got ruled illegal and Honduras is about to take their stuff. Building colonies in Antarctica is forbidden by treaty. And much like Thoreau's cabin in the woods, if you try to make a self-sufficient colony somewhere that's not actually isolated, you might think you've succeeded but actually have been cheating all along.
Yes, objectively there are better options, just as e.g. ITER could have been built a lot more efficiently if most of the countries had agreed to pay one country to make it, instead of making precision parts in a bunch of different countries and having to assemble them together. But engineering and politics are the art of the possible.
And who knows what the future holds in terms of population sizes? I also strongly disagree on the colonies not being able to engage in exchange. For a silly but very practical example sports in 0.3g are going to be insane. Jordan could jump something like 11ft and stay airborn for several seconds on Mars. That's going to be just be stupidly awesome to watch and play. MMA will look like a something out of a Chinese martial arts movie. For more mundane things, as the price of shipping cargo decreases the number of things available for trade increases. For example wine made in 0.3g will taste very different. Whether that's better or worse is yet to be discovered, but obviously such ideas will have no difficulty finding a market.
For better or for worse Mars (or the Moon) will also probably make amazing retirement places, especially if we can work on the scenery a bit. Taking that load of old bones might not only provide comfort but even increase longevity enabling a weaker heart to keep pumping a bit longer. And so on endlessly.
Before that there would be a lot of work off Earth, including manned work, but it would be in space or on the Moon.
They key is Lagrange points. Each pair of bodies (Sun/Earth, Earth/Moon, Sun/Jupiter, etc) have 5 points where the gravitational forces from the two bodies balance out in a way that makes it possible for something to orbit that point, even though there is no massive body at that point.
Two of the Lagrange points are stable, meaning that if something in orbit around them is disturbed it still stays around that point. The other three are unstable. Disturbing something there will cause it to get farther and farther away.
You can use this to move things from Lagrange points of one pair (Sun/Earth for example) to Lagrange points of another pair (Sun/Jupiter say) very cheaply. Get it to the starting point, and then nudge it into an unstable orbit that will have it getting farther and farther away. We can calculate these unstable orbits well enough to pick one that at some point is nearly tangent to an orbit of the destination Lagrange point that moves toward that point rather than away. A little nudge them can move our ship into that latter orbit.
The catch is that this is slow. It might take decades or more to make the trip.
The way you would use this in a colonization program is to build a series of unmanned cargo ships. Say a new cargo ship is completed every year. It would be stuffed full of supplies the colony will need, send to an appropriate Sun/Earth Lagrange point, and nudged onto its journey.
Let's say these ships take 30 years to reach the destination. After we've been doing this for nearly 30 years then we'd send a ship with the colonists. That ship uses a fast but expensive orbit. It would only need to carry the colonists, the supplies they need during the trip, and fuel and supplies for an emergency return trip in case when they get there they find some reason that they cannot stay.
Note that it doesn't need to carry any material to actually build the colony, or food and water for the colony. All that is in the cargo ships that are now arriving yearly. (If we are sure that the cargo ships are making it the human transport ship could even omit food, water, and fuel for an emergency return. Those can be on the first cargo ship).
You'd want to build the cargo ships on the Moon, or build them in space using resources from the Moon, because getting from the Moon to Lagrange points takes a lot less energy than getting from the Moon to Lagrange points.
The most plausible path then is to greatly expand industrialization of the Moon and the space near Earth. Probably then expand that to include space bases at some of the Lagrange points.
Then it is time to start working on colonization.
Unfortunately we'd probably not do Mars this way. If I recall correctly the low energy Lagrange transfer orbits to Mars are particularly slow--over a thousand years if I remember correctly.
https://idlewords.com/2023/1/why_not_mars.htm
Seems like the most conservative approach would be to send the return vehicle first, empty. Once it's landed safely on Mars and all systems look good, it would be reasonable to send the human crew in a 2nd vehicle?
Sounds potentially horrific to test with humans:
> able to communicate home by radio, but forced by unalterable cycles of nature to wait months or years for a rescue ship.
Of course, the difference is that compared to the conditions that await on Mars, a roaring blizzard on Antarctica is a balmy spring day. The air may be cold but at least it's breathable.
It's irritating to see people claim it's colder than antarctica but never a discussion how the reduced atmospheric pressure makes it easier to keep warm.
Here's a mission profile created by NASA [1] that gets you to Mars quickly (185 days), lets you stay there for 30 days, then gets you back to Earth quickly (250 days). The departure date is 7-Apr-2033.
[1] https://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NE...
An aluminum hull is nice because it does double duty, but you don't need to make it thicker than the structure requires just for radiation purposes. Instead you would add internal shielding. It's also smart to use food (and the resulting waste) and other consumables as shielding, since you need to carry that mass anyway.
You should realize that there's no simple way to convert from aluminum to polyethylene: it's not as simple as "PE is X times better." Due to secondaries aluminum stops improving after 30 g/cm^2,[1] hence why their chart (bottom line) levels out. PE doesn't have that problem, and lower dose rates are achievable versus what the author states.
TL;DR regardless of if you call it a "standard" or not, the author is still using bad math to overstate the actual risk.
[1] Figure 3, solid black line https://ntrs.nasa.gov/api/citations/20170005580/downloads/20...
You can read the author's other work, that goes into great detail about different types of shielding, if you want to gain confidence in his math. The upshot is you need many meters of polyethylene to effectively shield the heavy ion component of GCR, which is what the fuss is about.
But the point of that particular diagram is not shielding, but to illustrate the 2-3x uncertainty in estimates of tumor risk based on our poor understanding of high-Z ion exposure.
There were never any efforts to surpass that stay because it's completely unnecessary.
It's likely that some of these big unknown problems will similarly evaporate or prove to be easily solved once we actually do stuff like put humans in deep space ad on the moon for serious chunks of time.
I expect before people go that SpaceX will put a small constellation of starlink satellites in orbit of mars. I could also see them putting a bunch of probes on a starship and having them separate in martian orbit, landing at candidate sites. The combination of the 2 will lead to a lot of valuable data to decide where humans will land first.
Around mars it's likely the satellites will be in a higher orbit, but there's no internet needing low latency there either, at least not at first. They could be a basis for a mars positioning system. If a lower orbit is used they could potentially use synthetic aperture radar to get high resolution scans of the surface. It's probable that many starships will already be waiting on the surface by the time humans make the trek out there. Presumably loaded with food, equipment parts etc... For how quickly the ships are fabricated we aren't looking at a scenario where ships are in short supply.
--
In recent years, there’s been a remarkable division in space exploration. On one side of the divide are missions like Curiosity, James Webb, Gaia, or Euclid that are making new discoveries by the day. These projects have clearly defined goals and a formidable record of discovery.
On the other side, there is the International Space Station and the now twenty-year old effort to return Americans to the moon. These projects have no purpose other than perpetuating a human presence in space, and they eat through half the country’s space budget with nothing to show for it. Forget even Mars—we are further from landing on the Moon today than we were in 1965.
In going to Mars, we have a choice about which side of this ledger to be on. We can go aggressively explore the planet with robots, benefiting from an ongoing revolution in automation and software to launch ever more capable missions to the places most likely to harbor life.
Or we can stay on the treadmill we’ve been on for forty years, slowly building up the capacity to land human beings on the safest possible piece of Martian real estate, where they will leave behind a plaque and a flag. But we can’t do both.
--
1. SpaceX/Starship lower the cost of human space exploration by possibly two orders of magnitude over the Apollo/Space-Shuttle era
2. We can increase the amount of resources allocated to space exploration.
For both of these reasons, we absolutely can pursue both tracks.
Similarly alot of his stuff about microgravity just handwaves away the fact that a lot of the mission will be spent in 0.3g. And, in terms of overall effects on the body 0.3g will almost certainly end up being closer to 1g than 0g. It'll make it much easier to do things like exercise and all the "normal" physics of things would be much closer to the environment we all evolved in, than in 0g where everything just gets super funky. In fact I wonder about the viability of simply wearing body weights while on Mars, something that obviously would not work in 0g.
The radiation stuff has also been pretty well researched and isn't likely to be a show-stopper, especially with normal measures for protection like using the water supplies as a shield.
But what do you base this on? Vibes? Because the article correctly points out that:
> This goes against our intuitions, but there have been bigger surprises in space.
Also I'd add that even the less well understood issue like vision decline generally has to do with things 'not going the right way' -- in this specific case 'stuff not going down' increasing the pressure on your ocular region (ever noticed how astronauts all seem to have kind of bloated heads while on the ISS?). On Mars (or any other body with some reasonable degree of gravity) these sort of things won't be a problem.
- assemble a quite large interplanetary craft in orbit, with plenty of redundancy in HW and supplies
- drop 50 tons of cargo on Mars beforehand: food (and/or food-growing necessities - packaged soil, hydroponic equipment?), medical supplies, etc.; so that in case of problems, astronauts can survive on Mars for years if need be
It's terrific for cargo, but not viable for crews.
Use chemical engines for the high thrust trans-Mars injection burn so you can exploit the Oberth effect, then use ion thrust to continuously accelerate the ship for a (modest but still helpful) reduction in travel time.
>They're also relatively unreliable
Given their simplicity i think it is among the most reliable pieces of tech around. 5 years non-stop - no issues :
https://www1.grc.nasa.gov/space/sep/gridded-ion-thrusters-ne...
Note that all this is just NASA so far without SpaceX/Musk applying their engineering magic yet which i think would significantly improve the mass, efficiency, etc.
Force = 0.236N (per your link)
Acceleration = 0.0000236m/s (acceleration = force / mass)
Seconds in 2 months = 5259600
Final Velocity after 2 months = 277 miles per hour (0.124km/s)
---
This is an extremely naive and optimistic calculation since I'm assuming the engine is weightless and does not require fuel or power. It's easier that way and still emphasizes the point perfectly fine. You're gonna need a lot more engines to get anywhere. And of course a 10 ton ship is not practical. The goal for Starship is to to have a payload in the hundreds of tons, let alone the entire vessel's mass.
You also only have half the distance to accelerate, because you then need to turn around and decelerate the remaining distance. And we're also ignoring landing/takeoff which obviously isn't happening.
>Force = 0.236N (per your link)
>I'm assuming the engine is weightless and does not require fuel or power.
10KW 10kg engine plus 40 kg expelled mass per 100kg total starting mass. Thus for 10000kg - 1000kg of 100 x 10kg 10KW engines, 4 tons expelled mass, 2.5 tons - solar panels providing power. 1 engine - 0.3N, 100 engines - 30N. 15km/s in under 2 months, plus 2 months deceleration. The same for 100ton ship or 1000ton.
>landing/takeoff
that is by local chemical Starships "shuttles" which would transfer people and cargo to/from the interplanetary ships. Using Starship shuttles to fuel the interplanetary Starship, though chemical one, has long been in the published SpaceX/Musk plans.
I'm sure you'll be interested in this concept.
https://iopscience.iop.org/article/10.1088/1538-3873/ac4812
And this related one.
https://www.frontiersin.org/journals/space-technologies/arti...
The nuclear can work far beyond Solar system while the running out of the expelling mass is the main limiting factor here. If we can collect the mass along the way i think we can get to Alpha Centauri with 2-5% of "c" instead of 0.3-0.5% i mentioned in the other comment here (and we can accelerate to even higher speeds on the distances larger than the one to Alpha Centauri)
I'm not a test pilot but I'm a licensed pilot and I'd sign up for a Mars mission in a heartbeat, even if there was a 70% chance of success.
We send people under the ocean for years at a time to live on nuclear submarines in arguable more dangerous and isolated circumstances and they don't blink at the opportunity. To be the first person on another planet? What an incredible, fantastic opportunity. I feel like we will need to return to a place (As a society) where we accept risks that push the boundaries of the human race. Something we had a lot of in the 1960s but not a lot of today.
I don't think any single crew deployment reaches a year.
> more dangerous and isolated circumstances
I think Mars is massively more dangerous and isolated. A submarine can plausibly return to port or surface to breathable air. There is no such option on Mars. Nuclear submarines are much larger than spacecraft and have much more room for comfort options. They have a much larger crew, and the knowledge that this happens all the time from many nations must be of some comfort.
There's also earthbound experiments like Nasa's CHAPEA programs (https://www.nasa.gov/news-release/martians-wanted-nasa-opens...) but they only go up to about a year.
I am pretty sure that your confident self would think a few times before signing the NASA paperwork with this number.
Mars is by orders of magnitude worse than living on a submarine.
I guess technically anything is arguable, but this seems absurd. Sure there's pressure and cold, but a submarine can hold 100+ people and surface in 10 minutes.
Mars is 10 months away with maybe 10 people. There's no surface. You can't scrub oxygen from the water, hell there's almost no water at all. You won't be crushed by pressure but you'll be bombarded by radiation.
Drop a submarine on Mars and you could be hundreds of miles from easily usable ice. You have to be careful about perchlorates and it's either soil- or ice-locked.
Mariner, Viking, Odyssey, MRO, Maven, MEX, TGO, MER, Curiosity, Insight, Zhurong, Perseverance, Ingenuity all over there like HELLO!?
But yeah, I know they meant to say "crewed" ... and the rest of this article seems accurate.
If they do intend to send couples, put them in a small room for a year first as part of their training and selection process.