[HN Gopher] The Shape of a Mars Mission
___________________________________________________________________
The Shape of a Mars Mission
Author : feross
Score : 111 points
Date : 2025-02-21 03:01 UTC (20 hours ago)
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| rhcom2 wrote:
| > The only way to explore Mars in our lifetime is to ditch the
| requirement that people accompany the machinery.
|
| It just doesn't make sense to me to send humans. Exhaust the
| science collection of robots first.
| keiferski wrote:
| The budget and general public interest will be 1000x greater if
| humans are sent.
|
| "Robots explore Mars" is a daily news highlight.
|
| "First humans land on Mars" is a global historical event.
| whiplash451 wrote:
| General public interest will vanish once people realize that
| the journey will last two years and likely start 30 years
| from now. Oh, and they won't see the event live anywways.
|
| The trip to the Moon was a free trip to Jurassic Park in
| comparison.
| oceanplexian wrote:
| If that's the case then what is the point?
|
| 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?
| 0_____0 wrote:
| If the goal is "put man on Mars" then that's what you gotta
| do. It's harder to make the argument that you need to do that
| in the service of science, or even offworld colonies, given
| the unsuitability and impracticality of those both.
| lmm wrote:
| What plausible path is there to offworld colonies without
| sending humans?
| whiplash451 wrote:
| If the end game is offworld colonies, then we should
| craft the whole adventure as a series of one-way trips,
| not two-way trips.
|
| That's a serious paradigm shift compared to what this
| (excellent) article describes.
| Ekaros wrote:
| For me first logical step is to ignore the getting there
| part. And prove that we can actually build colony here.
| In suitable location say for example Sahara or
| Antarctica. After those technological challenges are
| solved next step is to see how to get it to orbit or make
| same in orbit. And then we can start thinking how to get
| all the stuff over there.
| whiplash451 wrote:
| I agree. That was the sense of my comment too.
| somenameforme wrote:
| Colonies on Mars are what drove the founding of SpaceX.
| Elon was looking up NASA's plans about sending humans to
| Mars and found that they simply didn't exist. He wanted
| to send a greenhouse to Mars while streaming its growth
| to get people inspired and thinking big again. NASA
| wasn't interested, Russia wanted too much $$$, so SpaceX
| was born. A colony doesn't mean you live there forever -
| it simply means a permanent human establishment. Some
| people will want to go back to Earth, some will want to
| stay on Mars indefinitely.
|
| 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.
| whiplash451 wrote:
| My understanding is that what drove the founding of
| SpaceX was a promise for more efficient use of agencies'
| money in space programs.
|
| 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.
| somenameforme wrote:
| His main motivation was about making humanity a
| multiplanetary species, largely as a means of ensuring
| humanity's continuation. It sounds hyperbolic, but Earth
| has gone through multiple mass extinction events and
| we're rather overdue for another. And while those mass
| extinction events were all natural, there's also endless
| ways you can imagine us all managing to kill ourselves
| off. And, critically, all of these hyperbolic scenarios
| will seem extremely improbable up to the very day that
| one does inevitably happen. So the best time to start
| would be 50 years ago. But the second best time would be
| right now.
|
| 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
| burch45 wrote:
| This has been covered before but saying that Mars would
| be a "humanity guarantee" is actually extremely
| illogical, not the most logical. Short of the Earth
| getting blasted to tiny pieces in some way there is no
| scenario where Mars is more habitable than Earth. This is
| the sort of sci-fi Utopianism that this sober article is
| standing in opposition to. Mars may be the second most
| habitable place in the solar system and it's infinitely
| less habitable than a nuked-out fallout-ridden earth or
| an overheated green house earth. There is no magic
| scenario where Mars suddenly ends up with a magnetosphere
| and an atmosphere.
| somenameforme wrote:
| This logic does not necessitate Mars ever being more
| habitable than Earth. Imagine one of the countless
| doomsday scenarios - a large asteroid impact. What kills
| you is not necessarily the asteroid, but it flinging
| debris into the sky that blots out the sun, not only
| creating a massive cold, but also rapidly killing all
| plants which starts a rapid series of extinction events
| on up the food chain.
|
| 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.
| _DeadFred_ wrote:
| You could build a better 'colony' on earth to survive
| that event for way less money/effort/risk than a colony
| on mars. You aren't going to have a colony on Mars
| contributing back to the home planet in any meaningful
| way, and 1% of people left on Earth is still 80,000,000,
| many more than will be in a Mars colony.
| somenameforme wrote:
| Building colonies in-planet that could survive all
| possible scenarios would probably be impossible. But even
| if it were you'd face a pretty simple problem - who would
| ever want to live for there? You'd likely end up living
| in conditions that would make life on Mars look pleasant,
| without any of the upsides that might take people to Mars
| - adventure, ideology, commercial aspirations, perhaps
| even religious (you know the Mormons will want a planet
| or two), and of course 0.3g!
|
| 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.
| whiplash451 wrote:
| The whole "let's by insurance for humankind" story is
| totally valid in my opinion.
|
| 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.
| _DeadFred_ wrote:
| We could buy insurance for humankind underground here on
| Earth much sooner and much cheaper. Plus that could kick
| start post human Eloi so win win.
| 0_____0 wrote:
| Hah! I wrote my comment sort of quickly and I knew
| someone would pick that out!
| tzs wrote:
| There's not really a plausible path to colonies on other
| planets (or on moons of Jupiter or Saturn) that needs to
| send humans there soon. Establishing such a colony and
| getting it working well enough to actually last would be
| a long term project, and it would be decades before it
| got to sending people.
|
| 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.
| hagbard_c wrote:
| Yes, well, maybe logically speaking that would be true.
| Practically speaking hardly anyone blinks an eye when 'society'
| daily sends young (mostly) men into harm's way whether that be
| by employing them in known dangerous professions such as
| logging (etc.) or by sending them to war. _According to the
| Geneva Declaration on Armed Violence and Development, more than
| 526,000 people die each year because of the violence associated
| with armed conflict and large- and small-scale criminality_ [1]
| while the world just keeps on turning. Nobody would even blink
| an eye if that number changed to 525.000 per year by putting
| dangerous criminals behind bars and keeping them there or by
| eradicating some terrorist group somewhere nor would they loose
| sleep if it changed to 527.000 per year after some conflict
| somewhere flared up again. Life is not as precious as it is
| often thought to be by most of us here on this site. Seen in
| that light it makes a lot of sense to choose 1000 volunteers
| out of the millions who would show up if asked to go on a
| mission to Mars, success not at all guaranteed and quite likely
| to be a one-way trip for the foreseeable future. Mars has been
| explored by a multitude of probes and rovers so sending the
| next one, no matter how advanced, will not cause much of a
| stir. Sending 1000 people to Mars with the intent of
| establishing an outpost will 'rock the world'. If successful
| (which is not at all a given) it would be one of the greatest
| achievements of our species while a successful robot mission
| would just be another tick on the list.
|
| [1] https://databank.worldbank.org/metadataglossary/world-
| develo...
| knome wrote:
| >Life is not as precious as it is often thought to be by most
| of us here on this site
|
| starting anything by throwing out the value human life seems
| like a bad direction.
| somenameforme wrote:
| I think the person you're responding to had a solid point,
| but he derailed it with his own examples. It's not about
| "throwing out the value of human life" but appreciating
| that risk is something that, in many endeavors, is going to
| remain relatively high even if you make every effort to
| minimize it.
|
| 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.'
| XorNot wrote:
| Conversely humans are absurdly bad at statistics - i.e.
| "an astronaut feels he has a 50 to 70% chance of
| success"...isn't a real prediction. It isn't based on any
| failure analysis.
|
| 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).
| somenameforme wrote:
| You're doing some improv here based on your intuition
| when history has a way of surprising us. So what was the
| "actual" failure analysis and risk percent? It didn't
| exist. "Mathematical risk analysis was used in Apollo,
| but it gave unacceptably pessimistic results and was
| discontinued." [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/dow
| nloads/20...
| pyrale wrote:
| "Many of them will die, but that's a sacrifice I'm willing to
| make".
| hagbard_c wrote:
| You show a Hollywood quote, I'll raise you a better one:
|
| _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 1/4 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.
| somenameforme wrote:
| I think people are more enthusiastic about robots than
| justifiable, because they see things like the Atlas robot and
| imagine that's the future. In reality the first man on Mars
| will likely discover _far_ more in a week than we have in more
| than 50 years of probes, or in all probability would in 50
| more.
|
| 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.
| varjag wrote:
| _In reality the first man on Mars will likely discover far
| more in a week than we have in more than 50 years of probes_
|
| 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.
| somenameforme wrote:
| Initial manned missions anywhere will never depend on in
| situ resource utilization, like soil, anywhere. And they
| will also assume that the environment is toxic until proven
| otherwise. You want redundancy to ensure that when things
| go wrong, which they will, it doesn't necessarily mean
| everybody dies.
|
| 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-perseveran
| ce/scie...
| varjag wrote:
| This is because there are increasingly fewer big
| discoveries to be made. No, an astronaut with a shovel
| won't excavate a lost Martian city, it'll be more of ISS
| science but in gravity and with sanitizer smelling dust.
| somenameforme wrote:
| We haven't even realistically begun to explore Mars.
| There are vast underground cave systems, it's still
| unknown what lays under the moist surface areas, and so
| on endlessly. Heck, we haven't even been able to expose
| subsurface strata. Even searching for metal deposits will
| be extremely important. But these are things we can't
| realistically do with rovers anytime in the foreseeable
| future.
| kibwen wrote:
| _> But these are things we can 't realistically do with
| rovers anytime in the foreseeable future._
|
| 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.
| tagami wrote:
| For those that were able to attend last week NASA Ames and
| USGS held the Offworld Resources workshop. Mining
| companies, advanced sensor tech (like muon tomography), and
| even genetically modified organisms to capture metals. Many
| of the questions and thoughts posted in this thread were
| covered.
|
| https://www.investmets.com/nasa-workshops-aim-to-merge-on-
| an...
| exitb wrote:
| Big part of the problem is how big of a hurdle it is to
| actually send a robot to Mars. I imagine that once we have a
| cheap and reliable platform to reach the surface, we could
| iterate the robots much faster.
|
| If you had a budget for one human mission, or a dozen new
| robots every two years, which one would you consider more
| beneficial?
| whiplash451 wrote:
| > In reality the first man on Mars will likely discover far
| more in a week than we have in more than 50 years of probes
|
| 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.
| devit wrote:
| This seems to be a problem with rocket/lander technology
| resulting in a ~900kg weight limit on Curiosity.
|
| 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)
| somenameforme wrote:
| It's not just the lack of air. You'd need an entirely
| different power and hydraulic system. And any sort of
| maintenance, liquid changing, etc is completely out of the
| question. And you need to be able to ensure you can capably
| operate it with a ~40 minute round trip time between action
| and getting a response. And then you need to be able to do
| all of this with temperatures that regularly drop down to
| -60C with high radiation levels, and so on.
|
| 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.
| ourmandave wrote:
| And why all the people involved cry tears of joy when
| they hear, "We're safe on Mars" after 7 minutes of
| terror.
| glenstein wrote:
| >The fundamental problem is that moving parts break.
|
| 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.
| layer8 wrote:
| I'm not an AGI believer, but I think the time horizon for AGI
| robots on Mars might actually be shorter than the one for
| humans on Mars.
| thaumaturgy wrote:
| Humans are extraordinary machines.
|
| 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.
| glenstein wrote:
| I can certainly agree that humans, regarded as perfected
| creatures of biological engineering, would make for an
| extraordinary Mars rover. You can make the case that we even
| the best among all animals for that job here on Earth (we are
| _that_ good, a fascinating convo for another thread).
|
| 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.
| xvokcarts wrote:
| > 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.
|
| Yeah, we've got great fine motor skills and high dexterity,
| but are obviously still too dumb to emulate those parts
| effectively.
| njarboe wrote:
| It doesn't make sense to send humans except many humans want to
| go. Those humans are working on the project to go to Mars, not
| send robots to Mars. We can do both of course.
|
| 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.
| schiffern wrote:
| In the spirit of xkcd 1232[1]...
|
| 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...
|
| [1] https://xkcd.com/1232/
| NegativeLatency wrote:
| Would love to see a (robotic) sample return mission, pick up some
| of the piles of specimens from one of the rovers.
|
| 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.
| decimalenough wrote:
| Eh, we've done it before. Read up on Magellan's
| circumnavigation, the colonization of Australia or the
| Shackleton era of Antarctic exploration.
|
| 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.
| trhway wrote:
| napkin for ion drive powered by solar - tech available today (and
| nuclear as the power source for the ion drive instead of the
| solar - tomorrow for Mars and beyond) - looks much better than
| chemical even for Mars. As SpaceX already using ion drives on
| Starlinks, and the SpaceX will be the one going to Mars, i'd
| expect that it will be ion drive.
| idlewords wrote:
| Solar electric propulsion has great specific impulse [i.e.,
| efficient use of propellant] but very low thrust. You're
| forever spiraling away from and then down into gravity wells.
|
| It's terrific for cargo, but not viable for crews.
| trhway wrote:
| not forever. You can get to Mars faster than with chemical,
| something under 90 days one way in some reasonable
| configurations.
| zardo wrote:
| What does that look like? A ten ton ship including 100
| square miles of solar panels?
| trhway wrote:
| You need about 10KWt per 100kg, i.e. 50m2 of panels. For
| 10 tons it would be under 5000m2, ie. like 70x70m. The
| panels do need to be relatively thin. Less than half the
| mass - 4 tons is the expelled mass (using say those NASA
| drives with 3500 Isp). And if you get panels at 0.5kg/m2,
| you'd get to 15km/s in under 2 months with about 3.5 tons
| for the rest of the ship including payload. More panels -
| either thinner ones or with less payload - faster time to
| Mars. Nuclear with ion drive - even better (and the only
| choice beyond Mars), can get you 35km/s+ (Voyager) or
| like 70km/s+ with 2 stages in under year.
| somenameforme wrote:
| You've definitely missed some decimals somewhere and/or
| are not considering the amount of thrusters needed. Ion
| thrusters total thrust is measured in the millinewtons
| and they have a very poor thrust:weight ratio (which does
| not account for the energy source mass). They're also
| relatively unreliable making them generally unfit for
| round trip missions without excessive redundancy which
| further increases the mass and thus the number of
| thrusters needed. Almost like a sort of microcosm of the
| tyranny of the rocket equation.
| trhway wrote:
| 7KW NASA drive weight about 10kg. At 10KW it would expel
| about 8milligram/second for 0.3N thrust (even with paltry
| 50% efficiency). It will get ship of 100kg total starting
| mass to 15km/s in under 2 months spending under 40kg
| expelled mass. The arithmetic is very simple. (my
| favorite arithmetic here is 3 stage nuclear powered ion
| drive ship with increased voltage resulting in ~35000 Isp
| and thus getting 1000-1500km/s in 100 years, and thus
| 1000 years fly-by to Alpha Centauri, with the tech
| basically available today :)
|
| >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.
| somenameforme wrote:
| Mass = 10,000kg (per the initial topic)
|
| 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.
| trhway wrote:
| >Mass = 10,000kg (per the initial topic)
|
| >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.
| zardo wrote:
| > Nuclear with ion drive - even better (and the only
| choice beyond Mars)
|
| I'm sure you'll be interested in this concept.
|
| https://iopscience.iop.org/article/10.1088/1538-3873/ac48
| 12
|
| And this related one.
|
| https://www.frontiersin.org/journals/space-
| technologies/arti...
| trhway wrote:
| i'd say i hope for the hybrid - nuclear (especially
| fusion once we get to it) generates power while something
| like in your second link collects the mass for expelling
| from the drive. The nuclear can work far beyond Solar
| system while the running out of the expelling mass is the
| main limiting factor here.
| 0_____0 wrote:
| ?????? You definitely gotta try to explain that one
| schiffern wrote:
| I expect the best way to use ion thrusters would be to
| _combine_ them with chemical engines.
|
| 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.
|
| https://en.wikipedia.org/wiki/Oberth_effect
| insane_dreamer wrote:
| An interesting and fun read along these lines that examines many
| aspects of colonizing Mars, is A City On Mars, by the
| Weinersmiths
| Robotbeat wrote:
| Unfortunately, in spite of a lot of good material in it, it's
| also deeply flawed.
| beder wrote:
| How so?
| oceanplexian wrote:
| The author puts a Mars mission into a realistic perspective but
| also, I think there are people who are wired differently than
| they are.
|
| 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.
| Jabbles wrote:
| > years at a time
|
| 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.
| m4rtink wrote:
| IIRC British antarctic service does uninterrupted 2 yer
| contracts. Not Mars or a submarine but still 2 years.
| Cthulhu_ wrote:
| At least being outside doesn't kill you in those ones.
|
| 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.
| croes wrote:
| It wasn't about pushing boundaries, it was about beating the
| USSR.
| whiplash451 wrote:
| > I'd sign up for a Mars mission in a heartbeat, even if there
| was a 70% chance of success.
|
| I am pretty sure that your confident self would think a few
| times before signing the NASA paperwork with this number.
| micromacrofoot wrote:
| > arguable more dangerous and isolated circumstances
|
| 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.
| rqtwteye wrote:
| " We send people under the ocean for years at a time to live on
| nuclear submarines in arguable more dangerous and isolated
| circumstance"
|
| Mars is by orders of magnitude worse than living on a
| submarine.
| ETH_start wrote:
| I reluctantly upvoted this for the wealth of
| scientific/engineering knowledge it contains despite strongly
| disagreeing with some of its conclusions:
|
| --
|
| 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.
| somenameforme wrote:
| I remained neutral on it since I also thought it was an
| interesting and clearly well researched article, but I think it
| leaned a bit too heavily on some somewhat inappropriate analogs
| to things like like with the ISS. It's a deteriorating old
| station where astronauts need to constantly prepare for orbital
| reboosts, receiving cargo, running commercial experiments,
| literally plugging holes more recently, and so on. This doesn't
| really translate meaningfully to the responsibilities on an
| interplanetary mission on new hardware.
|
| 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.
| calcifer wrote:
| > overall effects on the body 0.3g will almost certainly end
| up being closer to 1g than 0g
|
| 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.
| somenameforme wrote:
| Most of the major negative effects from time in 0g are
| pretty easy to derive from first principles - like the loss
| of bone density and muscle mass. The cause is simply a lack
| of muscular exertion. In 0g you don't really have much of
| any recourse against this except lots of mostly elastic
| based exercise, so astronauts on the ISS spend 2+ hours
| every single day just exercising, and it still isn't
| enough. On Mars the deterioration will obviously be lesser.
| And you also have much easier solutions not only in terms
| of working out but also passive, like the proposed body
| suits.
|
| 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.
| gattr wrote:
| Good point, we don't have to exactly follow the "astronauts in
| a small tin can, where everything must work flawlessly" way.
| With Starship (or its future iteration/successor) we can:
|
| - 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
| maxglute wrote:
| Has there been discussions on who to send on a "man"ned mission?
| Apollo had height and weight limitations for an average male, and
| now that DEI is dead, I wonder if it's more prudent to proritize
| sending smaller people (really light women) because sexual
| dimorphism seems to be a thing in the military.
| somenameforme wrote:
| Women tend to be substantially more susceptible to radiation
| related issues. [1] In reality though I think the main issue
| (outside of competence/merit) will be making sure people stay
| psychologically sound being tens of millions of miles away from
| Earth, for years. So in that case I wouldn't be surprised if
| they end up prioritizing highly capable couples.
|
| [1] - https://pmc.ncbi.nlm.nih.gov/articles/PMC6509159/
| Cthulhu_ wrote:
| I'm no psychologist but sending couples is a really bad idea.
| It's a mission, not a Big Brother style relationship test.
|
| 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.
| maxglute wrote:
| I think if long term supplies bottleneck, one would pick for
| physiology that requires less, i.e. 100lb person consumes
| ~50-60% calories as 200lb person. Or for same supplies you
| get much more brains/work done. Light lesbians with no need
| to worry about pregnacy fits the bill.
| schiffern wrote:
| Aluminum is a poor material choice for thick radiation shielding,
| since it produces lots of secondary radiation and it's
| inefficient due to its high atomic mass. Polyethylene, which is
| nice and hydrogen-rich, is widely understood to be superior.
|
| 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.
| somenameforme wrote:
| Water is a big one. Missions to Mars will be carrying tons of
| it, and it's an absolutely excellent radiation shield.
| idlewords wrote:
| I think you misunderstood a diagram; grams of Al per square
| centimeter is a standardized unit of shielding in the
| literature, not an engineering choice.
| schiffern wrote:
| That doesn't matter though. Since it's not representative of
| the real shielding, it's an inapplicable standard to use for
| this problem.
|
| 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/cita
| tions/20170005580/downloads/20...
| idlewords wrote:
| I didn't choose AL shielding as the reference standard to
| use in the literature; I'm sorry it bugs you.
|
| 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.
| schiffern wrote:
| >I didn't choose AL shielding as the reference standard
| to use in the literature; I'm sorry it bugs you.
|
| It's not that it "bugs me" (and please don't hide behind
| the "standards" excuse), it's that it deceptively
| exaggerates the radiation risk that is achievable by a
| reasonable thickness of radiation shielding.
| > The upshot is you need many meters of polyethylene to
| effectively shield
|
| The diminishing return is reached after only 20-30 cm,
| and there's essentially no improvement after 1 meter. See
| the paper I linked above. >But the point
| of that particular diagram is not shielding, but to
| illustrate the 2-3x uncertainty in estimates of tumor
| risk
|
| Then it's poorly written. You can illustrate that point
| without exaggerating the absolute tumor risk (see the
| vertical axis).
| verzali wrote:
| This is a very good article.
|
| 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.
| lapcat wrote:
| > It really puts the frustration I have with Musk's constant
| "we're going to Mars" in context.
|
| 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.
| Cthulhu_ wrote:
| For sure; as the article points out, a viable trip to Mars
| requires a ton of investments yet, but Musk is currently
| helping dismantle NASA and the ISS, probably with the intent
| of sending more high value contracts to SpaceX.
|
| 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.
| somenameforme wrote:
| What you're saying doesn't even make any logical sense.
| Musk is the primary contractor for ISS contracts and given
| the shit show that Boeing has turned into it's safe to call
| him the exclusive contractor for ISS contracts.
|
| 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.
| lapcat wrote:
| > Musk is the primary contractor for ISS contracts and
| given the shit show that Boeing has turned into it's safe
| to call him the exclusive contractor for ISS contracts.
|
| 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.
| throw0101a wrote:
| > _Musk is the primary contractor for ISS contracts and
| given the shit show that Boeing has turned into it 's
| safe to call him the exclusive contractor for ISS
| contracts._
|
| 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.
| njarboe wrote:
| Blue origin is doing pretty well. Got partly reusable
| rocket to orbit recently. NASA has no reusable rocket in
| development. This is fine, as the private market is doing
| it, but SLS needs to be retired soon. Maybe after the
| manned moon landings?
| somenameforme wrote:
| The commercial crew program started in 2011, the same
| year that the Space Shuttle was retired. From 2011 to
| 2020 (when SpaceX first sent astronauts to the ISS) we
| were 100% dependent upon Russia. That's undesirable not
| because of Russia, but because it's plainly ridiculous
| for any superpower to not have the power to independently
| send humans to space! SpaceX also won the _exclusive_
| contract for commercial crew. Boeing managed to get this
| overridden with political connections forcing NASA to not
| only also accept their bid but to pay their dramatically
| larger asking price.
|
| 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.
| alienthrowaway wrote:
| > What you're saying doesn't even make any logical sense.
| Musk is the primary contractor for ISS contracts
|
| 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.
| throw0101a wrote:
| > _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"._
|
| Even getting all cars to be hybrids would be a huge win
| (either parallel or series / range-extended).`
| njarboe wrote:
| Have you tried the latest version of FSD. I recently got a
| Tesla with it and it is about at the level of someone who has
| been driving for a few months. Has made one or two non-
| accident mistakes over the last few months but nothing
| serious. Sort of a dangerous uncanny valley I have to be
| careful of and not just forget I need to pay attention still
| (it tracks your eyes to make sure you look at the road most
| of the time but you can still zone out if you are not
| careful).
|
| 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.
| enragedcacti wrote:
| > 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
| Robotbeat wrote:
| I think a lot of people just approaching this topic from
| largely ignorance are unaware of how hardcore Falcon 9
| has actually delivered on its promises, in spite of being
| mocked by its competitors.
|
| Starship is already well on its way to succeeding, in the
| big picture
| njarboe wrote:
| Falcon 9 proved the concept of reusability. Almost
| everyone does not understand what Starship will do for
| space travel. Like Musk says, imagine air travel where
| you throw away the plane after each flight. That is where
| space travel was at. Hope to go to a space station or the
| moon in my lifetime (dream about Mars).
| mlboss wrote:
| I don't see any problem in companies making huge profit. We
| live in a free market there is always an opening for new
| competitor to offer something at low price point that can be
| repaired. Nobody is stopping anybody to start such a company.
|
| 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.
| lapcat wrote:
| > I don't see any problem in companies making huge profit.
|
| 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.
| innis226 wrote:
| Just to play devil's advocate, Isn't he getting the ball
| rolling? Put aside his unrealistic timelines, at least he's
| trying to solve the rocketry part of the equation. I feel like
| this extreme hatred is unwarranted.
| Robotbeat wrote:
| The large rocket adddresses basically all the problems.
|
| 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).
| Cthulhu_ wrote:
| It would probably be smarter to launch multiple payloads than
| have everything in one big payload, a fire can take out the
| primary and redundant supplies for example.
|
| 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.
| Robotbeat wrote:
| SpaceX has always mentioned sending multiple ships at once
| for redundancy, starting with uncrewed precursors sending
| supplies ahead of time.
| kibwen wrote:
| This is irrelevant and completely ignores the OP. We've
| had rockets capable of going to Mars since the 60s. More
| rockets do not solve the problem. Cheaper rockets do not
| solve the problem. Please read the article.
| Robotbeat wrote:
| Please read my comment. More mass makes solving virtually
| every challenge of Mars missions far, far easier.
| avmich wrote:
| Biggest problems are microgravity, radiation and lack of
| redundancies of various kinds. All are solvable by adding
| payloads.
| PaulHoule wrote:
| Well there is the "one-way trip" version which takes out some
| risk but trades the risk of losing 4 astronauts for the risk
| of losing 400 or more.
|
| 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-...
| Robotbeat wrote:
| The atmosphere of Mars is 3% nitrogen, so nitrogen can be
| extracted just from the atmosphere.
|
| 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.
| Robotbeat wrote:
| I wonder why my comment got downvoted? I thought it was
| pretty thoughtful and addressed the comment and article's
| claims pretty directly.
| jamleha wrote:
| https://news.ycombinator.com/user?id=jamleha
| Robotbeat wrote:
| We send spacecraft to deep space for decades on end, not just
| months. Oh, you meant CREWED spacecraft...
|
| 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...
| Cthulhu_ wrote:
| On the one side, you have a point, but on the other... as the
| article mentioned, a moon round trip can be done in the span
| of a week, they can set the craft on a trajectory so that it
| has a free return even if the thing becomes uncontrollable.
| Not so for Mars trips, after a few hours they're committed to
| the trip. The article then mentions everything that can go
| wrong.
|
| 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.
| Robotbeat wrote:
| "Current day technology" is sort of poorly defined because
| you can make new technology in one day. "Current tech" is a
| fake constraint, because even preparing for a launch in two
| years, you'd be developing new technology all along the
| way.
|
| 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.
| Retric wrote:
| > you can make new technology in one day.
|
| 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.
| somenameforme wrote:
| The "To the Moon" speech was made in 1962 when we had
| basically no knowledge of space. We'd only sent a man
| into Low Earth Orbit for the first time a few months
| prior. 7 years later we'd land a man on the Moon. And
| we'd repeat this several times over until Nixon
| effectively cancelled the human space program in 1972.
| Obviously 7 years is not one day, but I think 1 day was
| clearly figurative rather than literal.
|
| 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."
| Retric wrote:
| > The "To the Moon" speech was made in 1962 when we had
| basically no knowledge of space.
|
| 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.
| somenameforme wrote:
| Obviously we'd been wanting to go to the Moon before that
| speech, but there was no secret technology that we were
| just being coy about. We still knew nothing, had nothing
| and were in the process of figuring out what John Glenn's
| fireflies were during a flight where, if he wasn't such
| an uncannily good pilot, he probably would have died.
|
| 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.
| Retric wrote:
| > To the average layman
|
| 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.
| somenameforme wrote:
| No, NASA also didn't think it was possible at the time.
| There's an informative little paper here. [1] It only
| gets more informative from the first sentence,
| "Mathematical risk analysis was used in Apollo, but it
| gave unacceptably pessimistic results and was
| discontinued." By the time of the launch to the Moon
| NASA's internal estimates were looking at around a 50%
| chance of success based on Gene Krantz's (mission
| controller) "Failure is Not an Option" book.
|
| 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/dow
| nloads/20...
| Retric wrote:
| You're confusing specific low odds of success for "didn't
| think it was possible."
|
| 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.
| somenameforme wrote:
| What I'm demonstrating is that we indeed knew basically
| nothing. There was no secret tech or expectation of
| success. Mathematical models doomed the entire idea to
| failure, and all the way up to the day of the launch
| people who spent years in a bubble of optimism still
| didn't really expect more than a 50% chance of success.
| Retric wrote:
| > a 50% chance of success.
|
| _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.
| Robotbeat wrote:
| On the contrary, we can easily get people there alive.
| What exactly do you think is beyond our capacity to send
| crew to Mars while still being alive? Crew regularly do
| year long expeditions on ISS (edited for clarity), with
| total radiation dose similar to Mars transit (and show no
| measurable effects of that radiation).
|
| 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.)
| idlewords wrote:
| No one has ever done a "years long" expedition to ISS,
| and the radiation flux in transit to Mars, in particular
| GCR dose, is much higher than experienced on the space
| station.
| Robotbeat wrote:
| I'm well aware, just mistyped. The total equivalent
| radiation dose on a fast transit to Mars is less than
| some ISS expeditions.
|
| 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.
| idlewords wrote:
| Total GCR dose is 3-5x in transit to Mars compared to
| what you get on ISS; on the Martian surface it's from
| 1.5-2x the ISS dose. (see https://www.swsc-
| journal.org/articles/swsc/pdf/2020/01/swsc2...).
|
| On a long-stay Mars mission, that adds up to 12-18 times
| the accumulated GCR exposure compared to a six-month ISS
| increment.
| Retric wrote:
| The world record duration still sits at 438-days after 35
| years. We limit people below that due to medical issues,
| suggesting no we don't know how to safely do multi year
| space flight.
|
| It's possible people spending significant time on the
| surface of mars would recover, but that's more
| speculation than proven.
| Robotbeat wrote:
| Note that Mars' surface has a similar radiation dose as
| ISS, as measured by the Curiosity rover. (This includes
| the quality factor.)
| Retric wrote:
| A significant part of that is because it's much further
| from the sun.
|
| 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.
| idlewords wrote:
| It does not; see the paper cited in my other reply to
| you. GCR dose is 1.5-2x on Mars compared to ISS.
|
| 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.
| throw0101a wrote:
| > _We send spacecraft to deep space for decades on end, not
| just months. Oh, you meant CREWED spacecraft..._
|
| 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._
|
| * https://www.lpi.usra.edu/features/ala_msl/
| SECProto wrote:
| That isn't a very useful statistic - all you should really
| glean from it is that landing on Mars is hard. The US has
| done it 9 out of the 10 times it tried, so it seems
| reasonable that it would succeed.
|
| https://en.wikipedia.org/wiki/List_of_Mars_landers
| sangnoir wrote:
| It was done by NASA, who have a culture of triple/
| quadriple checking and being very careful about
| mitigating risk in ways that may seem inefficient to
| some. I don't see NASA leading the effort to Mars in any
| meaningful way besides being a conduit for money from the
| treasury.
| Robotbeat wrote:
| If NASA astronauts are on board, they will be triple and
| quadruple checking things, like they did for commercial
| crew and are doing for HLS.
| sangnoir wrote:
| > 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
|
| 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"?
| Robotbeat wrote:
| We are, in fact, in the middle of a Cold War again. Also,
| our economy is far larger and we have launch technology
| that makes such efforts far cheaper/
| IncreasePosts wrote:
| A big rocket is probably the biggest obvious hurdle. What are
| other people doing to get us to mars that is better than musk's
| approach?
| notahacker wrote:
| No, the big rocket is the easy bit which has been done many
| times before.
|
| 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.
| avmich wrote:
| It's easy if you use additional payload available with
| bigger rockets.
|
| 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.
| darkwizard42 wrote:
| No, the biggest hurdle is having astronauts survive the
| journey (health and successful landing/departure of Mars). It
| would be over 3 years in space to round trip to Mars with
| current tech. We haven't had an astronaut in space
| continuously over ~1 year...the body suffers tremendously in
| a low gravity environment and you would have to handle SO
| many side effects and redundancies in life support etc.
| Robotbeat wrote:
| Artificial gravity would address those issues. The big
| rocket (ie mass margin) also addresses life support
| redundancies (and allows you to use simpler, much more
| reliable methods like used on short duration spaceflights).
| gosub100 wrote:
| I'm sure this question has been addressed already, but why not
| try a 1-year moon base first? With a hot standby ready to
| either rescue them or drop a brand new habitat.
|
| Not to mention launching to Mars from the moon is easier (in
| some respects, not all).
| ckemere wrote:
| This is exactly what NASA has had on its timeline since the
| Obama era ("Constellation"). Trump #1 didn't like the slow
| timeframe (get to the moon faster - "Artemis"). Current plan
| from Trump/Elon ("let's scrap the space station and the moon
| and go to Mars ASAP") sounds like an even more accelerated
| abandonment.
| Robotbeat wrote:
| On the contrary, Constellation is from the Bush era. Obama
| tried to cancel it (with good reason, to be fair!), and
| then Trump started an accelerated Artemis, which basically
| combined both the Obama program of record with
| Constellation.
| gosub100 wrote:
| I think a moon colony would be awesome. We could watch them
| in near real time. Learn what it actually takes to maintain
| a habitat while still having a safety net. Yes I know NASA
| and others have been researching that since the 60s anyway,
| but it needs a dress rehearsal with modern technology. Go
| to moon, prove we can sustain N humans, process the waste,
| recycle the water, make O2, etc. Do it on the lunar
| surface, then go big.
|
| 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.
| PaulHoule wrote:
| I'm picturing that the safe way forward is to send a 1000 day
| duration mission to LEO which would remain autonomous except in
| case of critical failure. Probably a series of them.
| jpm_sd wrote:
| Don't miss part 1 (2023) for context.
|
| 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?
| ckemere wrote:
| I had the same thought, but this has no effect on necessary
| delta-V. In terms of risk, I suspect it's already baked in to
| his analysis at some level. The risk comes from human-time-on-
| planet or time-in-space, which having a return vehicle doesn't
| change.
| tagami wrote:
| a variable not covered: mental well being on the long voyage.
| potato3732842 wrote:
| During the second world war the British not so famously (it's not
| like it's something you brag about) spent a lot of money and
| effort building extremely heavy tanks or assault guns designed to
| help a spearhead a breach of the Siegfried line. They turned out
| to be mostly unnecessary due to a combination of factors that can
| be roughly summed up as "quantity has a quality all its own" and
| the projects were steadily cancelled as the war in Europe wound
| down.
|
| 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.
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