Confronting the Credibility Gap for Crewed Exploration of Mars
caseyexaustralia.blogspot.com
caseyexaustralia.blogspot.com
There's the expensive approach. Send multiple unmanned tanker ships into Mars orbit and have them rendezvous into an orbital supply depot. Send landing tanker ship to rendezvous with them and refuel with enough fuel for a powered landing. Landing ship descends. Repeat to build up fuel reserve on Mars surface. Manned ship then docks with orbital supply depot and crew switches to lander. Lander descends, lands near fuel reserve, and refuels for ascent.
Ascent is to Mars orbit and docking with the orbital supply depot. Crew switches back to long-haul ship, refuels it, and goes back to Earth.
You still need a lot of delta vee to get a harpoon+cable from orbit to the surface. You can't just fire it straight down, you have to cancel most of your orbital velocity (which would have to be way out at geostationary). Dunno what the strength requirements of the cable would be either, but I imagine the answer is "not small".
Doing the same trick to Earth probably wouldn't be that much harder than Mars. So maybe, once you've solved the hard problems, you wouldn't have to worry so much about mass-to-orbit anyway.
Many of the ideas for visiting other planets could and should be tested on earth first. I think we need to get comfortable with visiting the moon and performing large scale industrial projects in space before we have any chance of visiting remote planetary bodies and returning.
That's what I said. The trouble is there's no "just" about it. A cable long and strong enough is going to be extremely heavy, never mind the "harpoon". In a traditional "harpoon" the cable is a small fraction of the total mass - you can't really afford that kind of design (shoot heavy thing, drag negligible thing behind) so it's not clear how the orbital dynamics would work. You'd be looking more along the lines of little tug rockets spaced along the length of the cable.
>Many of the ideas for visiting other planets could and should be tested on earth first.
Quite. This Mars stuff is completely pie in the sky. Let's see a self-sustaining habitat in a desert on Earth, never mind even the moon. As an incidental benefit of solving this we would be able to perform sustainable agriculture anywhere on Earth.
> As an incidental benefit of solving this we would be able to perform sustainable agriculture anywhere on Earth.
True. Although sustainable on Earth usually also means economical. I would like to see a sustained habitat on the moon.
Off-topic, but your post popping up with the Hyperloop One name attached helped me decide[1] to sign w/ you folks instead of another company for Summer 2017, so see you in a few months!
[1] I was probably picking Hyperloop anyway, a cool Mars post + vague affiliation with Max just made it easier :)
A lot of these problems beg the question. Is Mars really the best target? Sure it's close but there are moons around Saturn that are interesting as well. Titan for example. Sure it's cold but it has a lot of atmosphere. Presumably landing would be easier. If we could learn to live underwater we could possibly visit Ganymede or Europa.
Human psychology is another, perhaps even bigger problem, also independent of destination. We've had various experiments with prolonged isolation, but none where the subjects know that they're never coming back to Earth. I'd say psychology has a >50% chance of wrecking the first manned missions to other planets/moons, unless we send huge ships with hundreds of people.
In the Red Mars trilogy by Kim Stanley Robinson, the author has come to the very astute observation that
a) no perfectly rational, mentally healthy human would volunteer for such a mission
b) there will necessarily be extensive psychological screening to ensure we only send rational people
thus c) the people who will be selected are likely to be non-rational actors very good at concealing their non-rationality from psychologists. Also known as people with psychopathic tendencies.
Who said they're never coming back to Earth?
>no perfectly rational, mentally healthy human would volunteer for such a mission
That's an easy problem to solve, as there are no "perfectly rational" and/or absolutely "mentally healthy humans", and have never been anyway.
And people can still be quite rational and mentally healthy and yet cherish the possibility to take such a mission, even if there's a possibility to die, etc.
In fact, it's needs no more troubled people than those that go to the army and are OK to be sent to war, or people that dive and explore the oceans, etc etc.
The thought of dying isn't the inherently problematic part, but rather the extreme isolation. People who go to war are there for only some months and have plans for going home, back to friends and family. People who dive and explore the oceans are isolated for a few days at worst; perhaps months in a nuclear sub, but there you have already a pretty large crew around you. Compared to decades spent isolated with a handful of people, and no return ticket to the rest of humanity, those are nothing.
Huh?
"The first crewed Mars mission would be expected to have approximately 12 people, with the primary goal to "build out and troubleshoot the propellant plant and Mars Base Alpha power system" as well as a" rudimentary base." In the event of an emergency, the spaceship would be able to return to Earth without having to wait a full 26 months for the next synodic period."
https://en.wikipedia.org/wiki/Interplanetary_Transport_Syste...
NASA, I believe, is currently trying to solve the problem with more efficient engines for interplanetary travel. Ion drives seem to be the preferred method, but there is still some research going on in nuclear thermal rockets.
That depends entirely on what they value. If they value their own safety, comfort, and health, then it wouldn't be rational for them. But if they value the advancement of future humans, honor, fame, legacy, scientific discovery, adventure, and so on (which may seem to be irrational things to value for someone in the first group) then it would be rational.
There are some people who will be excited about the fictitious ad from Earnest Shackelton "Men wanted for hazardous journey, small wages, and bitter cold, long months of complete darkness, constant danger, safe return doubtful, honor and recognition in case of success."
Floating around in aerostats on the cloud tops of Venus where it's roughly room temperature at 1 atm on the other hand... or living on the Moon where you can at least communicate with Earth in roughly real-time and are only 3 days away...
You seem to imply that the issue of radiation should cause us to reconsider whether Mars is worth it. But the same, and worse, problem people will have with Saturn too.
No roaming over the surface, though.
I don't get Venus cloud tops. I've never seen anyone explain how to transport, fuel and launch a Saturn V rocket from a zeppelin.
The lifting gas can be initially transported in a highly pressurized form (e.g. liquid helium). It would be enough to support a small initial platform. That platform can generate lighter gases right from the atmosphere, using solar energy. CO2 is pretty heavy, so even oxygen and nitrogen would be lifting gases. Hydrogen is also somehow available for extraction from the atmosphere. These gases could be used to support more and more incoming structures as they arrive from orbit. (Yes, easier said than done.)
The bigger problem would probably be compounds like sulfuric acid, hydrogen chloride and fluoride, etc, that would readily react with many construction materials, especially metals.
Given the atmosphere composition, it's probably even possible to synthesize both fuel and oxidizer for a rocket, e.g. hydrocarbons and O2 or HNO3. Launching a large rocket from a zeppelin is tricky. Launching a rocket from a plane has been shown to work on Earth, so it's possibly also doable from Venusian cloud tops. Again, easier said than done.
But still possible!
High temperatures killed them in a matter of hour or so, though.
First, for what is worth, I share your Mars questioning. But then I can't just let you downplay the distance factor with "sure it's close" glossing-over. One can find interesting tools out there¹ that may help grasping the astronomical distances better. The bottom line is that it just makes more sense to take our chances with planets closer to us and so far, at least with the landing on Moon, the humans respected in this regard their species' "rational" self designation.
¹ http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...
http://caseyexaustralia.blogspot.com.au/2016/09/spacex-mars-...
This means living underground, which defeats the point of going to Mars in my opinion. Elon mentioned using a local magnetosphere generator, which is one of those ideas that is theoretically possible but whose practicality seems questionable. How powerful a magnetosphere generator is required to deflect ionizing radiation? How much power generation capacity will a Martian colony have to spare? Will this require a Fusion reactor?
The only hope I have for Martian settlement is that Musk and his engineers are some of the most audacious and brilliant people on the planet. I will never bet against their success, and I wish them the best of luck.
I have been a space exploration fan since as long as I can remember, I just worry that humans have a tendency to focus on the wrong goals when ideals and emotion cloud our judgement (e.g. the Space Shuttle).
I have three questions:
1. Is it merely a question of mass? That is, if Mars were larger would the increased gravity increase pressure at the core and keep it molten?
2. If it IS merely a question of mass, is there any way to add mass to Mars which doesn't disturb its orbit? Because if you could, then you simultaneously solve both the problem of low gravity AND lack of magnetosphere, which together solve the problem of maintaining atmosphere. Basically the whole planet becomes extremely Earth-like
3. If increased mass wouldn't necessarily wreck its orbit, could something be done to "steer" asteroids from the Main Belt into collision courses with Mars?
I really don't know anything about orbital mechanics so maybe there's an obvious flaw in this (aside from the energy required to reroute that many asteroids).
Planetary-scale engineering is not only hard, it's inevitably slow.
I think cleaning up the atmosphere of Venus by spreading CO2-eating anaerobic air-suspended algae is more realistic, and the results would likely be nicer.
I've heard of the following approach. The spacecraft generates a magnetic field which spreads around it in flight, having some substantial size (order of kilometers). Relatively small amounts of matter (some gas) are constantly emitted from spacecraft, get ionized and trapped in the magnetic field. Such a low density thick "cushion" of ions makes the radiation shielding.
I'd like to learn more about effectiveness of such an approach.
I just fail to see this obsession with Mars. We don't even have manned landing on Mars and we are already having questionable stuff like "Mars One"
And finally (one for the conspiracists): nearly 50 years ago we landed on the moon without any of the technology we have today. Why hasn't there been any strides? Shouldn't it be cheaper to go to the Moon vs Mars? Shouldn't it be possible to colonize Moon more easily and faster than Mars?
Another huge factor is the lack of consistent solar power. 14 out of every 28 days have zero solar. Mars doesn't have this problem.
There are other lesser factors as well, off the top of my head: weaker gravity which may affect health, the psychological problems with 2 weeks of solid darkness every month, and less scientifically interesting.
However, it may be still worth considering.
My sense is that the social, political, and psychological barriers could be overcome for such a thing.
"Do you realise the astronauts
will run out of nitrogen on day
59 and die?"
So Mars One isn't really funny, it
has probably set back the credibility
of the movement by a decade.
There are definitely crucial moments in political science, when an absurd gaff completely botches a carefully crafted image, completely imploding the efforts of hundreds of people, and sinking an entire team permanently. Cringey things that seem to matter to the echo chamber of a 24 hour news cycle.
But I don't feel like hard science works that way. When it comes to real engineering feats, if one company tries to trade on faulty calculations, and their charade is laid bare, the smoke and mirrors disappear only to reveal the same bald truth that had always been there from the start: hard problems defy shenanigans.
A political failure doesn't deflate an engineering problem. Not in the same way it deflates a PR campaign. If the hard science was not respected, then there was no investment in a decade of progress to begin with.
So, these swindlers then maybe blew a decade of real funding, only to burn their investors with bogus project plans and proposals, ripping off charity and fomenting skepticism and suspicion? I think skepticism in this sphere is actually healthy, and separates the children from the adults.
Waste is a bad thing, and maybe real money disappears, but maybe that kind money came from the kinds of people who might have just as soon blown their cash on personal assistants, vacations and clothes. Clearly such investors were not "buying science," or they'd have known better.
So, then the only thing left is that maybe there's the premise that admirers of the charade would not have loitered on the sidelines, simply yearning to lend their support to the parlour trick they were true believers in. That they would have stepped up to the task, had they known progress was stalled. I don't buy that.
No matter what, I don't think there has even been a decade of effort spent on crewing a mission to Mars. It's all been so much conjecture. It's never seemed to be an easier idea than an underground moon base, and no one seems to be giving lunar round-trips or installations much more consideration than mars.
Space shuttle accidents and launchpad explosions cast the true hazards in a much more severe relief, but knowing that people are even trying and failing feels like much more significant progress than a lot of talk and faulty plans.
So was there really any "damage" done by some of these PR goof ups?
I could sense this was coming, and I stopped reading here.
This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurements we've been making of other physical constants for decades now.
This is a big ask. This is a huge ask.
Both he and I are firm believers of the scientific method though, so if researchers can show it experimentally then that's where the fun really begins. To my knowledge, the experiments until now have been fairly poor, with barely significant results (on the edge of noise).
Edit:
The 1) demonstrate and 2) explain parts are critical and it's not science unless you have 1). Preferably 2) also. EM has neither to match the magnitude of the claims until they can push something across the solar system and back (such that loss of mass is ruled out and the propulsive effect is without a doubt not instrument error).
That is hyperbolic. Pushing something around in orbit is sufficient to move forward (pardon the pun).
EM drive remains pretty controversial, and does present significant problems with explanation, and as an extraordinary device requires extraordinary evidence. So it could be conceivable not to focus too deeply on a remark which isn't the main point of the article.
I'm not dismissing your interest and excitement in the topic either. I'd love for it to be functional, and for us to learn new information on the way our universe works. The bar for entry is set particularly high on this, that's all :)
https://blogs.scientificamerican.com/guest-blog/its-not-cold...
HN discussion: https://blogs.scientificamerican.com/guest-blog/its-not-cold...
> Perhaps most surprising is that, in the formative years of atomic science in the early 20th century, some scientists reported inexplicable experimental evidence of elemental transmutations. In the 1910s and 1920s, this research was reported in popular newspapers and magazines, and papers were published in the top scientific journals of the day, including Physical Review, Science and Nature. The experiments, using relatively simple, low-energy benchtop apparatus, did not use radioactive sources so the results defied prevailing theory. Several researchers independently detected the production of the gases helium-4, neon, argon, and an as-yet-unidentified element of mass-3, which we now identify as tritium. Two of these researchers were Nobel laureates.
To think that our current models adequately explain every phenomenon in the universe is truly the height of hubris. They can't even explain every phenomenon that has been observed on Planet Earth, let alone universally.
Of course extraordinary claims require extraordinary proof - but we do a tremendous disservice by disincentivizing scientists from ever reporting a novel finding that disagrees with the prevailing theories.
Gotta love starry-eyed futurology people.
Just blanket suggesting that it is in no way possible without any evidence is no better than blanket suggesting it is possible without any evidence (well, it's a little better, since the laws of physics are on your side, but...)
The orbital motion of Mercury "violates" Newtonian gravity. There are other examples but I'm not trying to make a history lesson. I just want to point out, that science moves forward by impartial investigation of EVERYTHING. It's misguided to assume we know all and that there cannot be some thing we don't understand.
I'm as sceptical as anyone else about the EM Drive, but I want to understand "what the heck is going on with this thing that appears to move" more than I want to dismiss it as "not possible and obviously flawed because $ABC"
There are plenty of possible ways the drive could operate, and if it does work, it has the potential to significantly advance several fields of physics in a way no less valuable than other large expensive "hope this works" experimental physics experiments that no one is complaining about.
Mercury's motion does violate Newtonian gravity. General Relativity however simplifies to Newtonian gravity for various low-dimension applications though (i.e. an Apple falling from a tree, the orbit of the moon for most astronomical guidance purposes over that distance etc.)
In much the same way we don't account for the curvature of the Earth when building a house's foundations.
That's my point though: when you violate a fundamental physical law, it can't just be wrong. You have to somehow also account for why it doesn't happen all the time elsewhere (i.e. the effect is small to within experimental error over common measurement cases) and by necessity the new theory to explain it has to encompass the predictions of the old i.e. the benefit of Newtonian gravity was that it easily recovers the behaviour of nested epicycles of orbital motion (and made new predictions successfully where epicycles could not).
I still don't see how this is possible. In GR gravity travels at the speed of light, in Newtonian mechanics it is instantaneous. I have been unable to find an acceptable explanation for how these two very different universes can be compatible.
NASA also does the same thing, so don't feel bad.
Extraordinary claims require extraordinary evidence.