Space Elevator On Other Planets

>a 100kg weight on Earth only weighs 38kg on Mars

That is correct and not implying anything. It isn't stating the 100kg weight turns into a 38kg weight. It is stating the 100kg weight will weigh 38kg. Learn English.

Because kg is a unit of mass and not weight it is more appropriate to say that a 981 Newton object on Earth will only weigh 371 Newtons on Mars.

This is why astronauts are weightless and Photons are mass-less. F=ma and all that..

According to Wikipedia, we could theoretically build a space elevator on Mars with current technology, but Phobos would intersect with it and thus destroy it.

Moon Ferris Wheel Catapult.
Other shit is shit.

What if Phobos was made to be stationary/geosynchronous with Mars and we just built a bridge between the two?

And how are we going to live on Phobos if we can barely live on Mars?

The space elevator only gets you to the departure point (space station) to get to the O'Neill Cylinder. Phobos becomes the space station at the end of the space elevator. You don't actually live on it. This is in the OP.

But, that is something different and for a different purpose. It is kind of difficult to use a Moon-based thing like that to get people of Mars.

Kg is a unit of mass, not weight.
Go read a book.

How about you read the thread, kid.

38% gravity is easy enough to work with. Just walk around with weight trainers and you're good. It's not like dealing with 0% where your capillaries start bursting.

The only real problem comes up in prenatal fetal development, but it isn't entirely clear what those problems will be, until after you're born, and then there's rather obvious problems involved with growth.

That latter is likely not a problem, if you never intend to leave the planet or take a full G, but it'll certainly limit your survivability elsewhere should you choose to grow up on mars - plus that muscle mass prevents bone breakage, so martians born on mars, if such a thing is possible, would have to be careful as fuck, and be basically made of glass. On the plus side, all those calories saved on muscle mass would might go to straight to the brain, so you may end up with a race of extremely fragile super nerds.

The easy solution is to spend your prenatal development and at least the first few years of your life in orbital stations, as you suggest. You probably won't be as buff as an Earther, but at least you probably won't end up a walking glass skeleton. After a certain age, the same weighted suit should allow you to develop on the surface (or, more likely, sub-surface) just fine.

There's a fair amount of biological leeway - gravity on Earth varies by several percentage points, and folks born in low gravity zones, such as Sri Lanka, aren't significantly weaker than their counterparts born closer to the poles. So, while a ~60% reduction is no doubt going to be a problem, it's likely not as fatal as you're thinking.

>Gravity on Mars is too low for humans to live for generations on.
[citation needed]

>Just walk around with weight trainers and you're good.

Except when you start losing vision in 1-3 years.

nasa.gov

You dumbfuck.

Mars would work

You build it out in both direction from an orbiting asteroid, going up and down to balance the pull

Once it reaches the surface you secure it and build your elevators

We can figure this out. Perhaps sessions of centrifuge therapy to keep everything stimulated and properly weighted down would orevent this sort of thing

>nasa.gov
try harder

google.com/search?q=astronaut health low gravity site:nasa.gov

I wonder what % of time you'd need to spend in a centrifuge to prevent VIIP.

mars gravity is way too strong for a space elevator.
my guess is if we do construct a space elevator at some point it will be around one of the smaller moons in our system and the eventual long term goal being a space elevator on earths moon (also what the fuck is the name of earth's moon again ?)

>(also what the fuck is the name of earth's moon again ?)

"The Moon" Though it depends on the language and culture. "Luna" is the Latin version for instance. We have shit names for our stuff. The Sun, The Moon, "Earth" (because it is made of earth), The Local Group

try harder still. what makes you think zero gravity results are applicable to .38g? and where are your sources to back up that belief?

>fire burns but 62% fire won't

That only happens in microgravity freefall - so far the animals put under half a G for extended periods don't have any long term problems save slight loss of muscle mass. Though I've never read of anyone attempting to breed them under those circumstances.

>being this retarded

Atmospheric drag isn't why you make a space elevator.

It isn't the force of gravity that causes the issues, it's the rotation of the planet and the stress that induces in the structure of the elevator.

>atmospheric drag
what the fuck has that got to do with anything? space elevators are a good idea because rockets are fucking shit.

>He is factually just and an autism for fail to undestand the >impliying

It means that space is 100% dangerous to the human body (lack of gravity) and mars is only 62% dangerous to the human body (38% gravity of Earth's).

Like fire still burns and lack of gravity still causes problems.

Well, if we want to beat on the fire simile until it putrefies - there's a big difference in dealing with a fire that gets you to room temperature, a weaker fire, only giving you 38% of room temperature, and an absolute lack of warmth, leaving you at absolute freezing.

Mars provides nearly half a G, and that isn't a real problem for a grown human - not anymore than snow from lack of warmth - you can compensate for that shit. Unlike zero G, there's no bursting capillaries or weird blood flow problems are involved, and what little muscle atrophy is involved is easily compensated for with proper exercise and worn weights.

Growing up at that gravity level, or developing in the womb at said gravity level, might be a real issue though.

Which is where OP's orbital station solution comes in... But all the things that make it easier to build a space elevator on Mars, also make it easier to shuttle back and forth between the surface and orbital stations by more conventional means. So while the stations might be a solution, I don't see a space elevator being involved, lest some other tech comes along that makes them more practical.

On the other hand, by the time anyone is actually having children on mars, we'll also likely have a lot more bio-tech know how to deal with those development problems, in addition to, hopefully, having a better idea of what those problems are. ...Provided we don't have any sexy, horney, unprofesional astronauts on long stays, discovering these problems the hard way.

Rockets are fine once you have reusable ones
How many billions will a space elevator cost? How much will it lift in tonnage per year?

We'll be launch off methane rockets for the foreseeable future

Your head is 100% full of shit.

Why is Mars' low gravity a problem? Can't you just fake higher gravity by wearing weighted clothes?

That compensates for muscle atrophy in adults - it doesn't, however, compensate for a fetus in development, nor for passive and internal musculature in childhood development.

Though the latter might be okay, provided you are alright with the resulting child being unable to survive on its ancestral homeworld, among other possible issues.

>travel to alternate universes until you find one where there is no Earth
>build a space station
>travel to Mars
>travel to alternate universe until you find Mars elevator
>it's bound to be there since it would be much easier to build
>steal technology
>go back

Gravity is a very important factor in development. But since no one has ever spent a significant amount of time in 1/3 earth gravity we dont really know what effect it will have

I think NASA is currently doing some experiments on the ISS. They measure the development of plants, rodents and such, in zero gravity. Can't remember if they actually published any papers yet.

sure
but zero g is not anything the same as low g

Perhaps. Tough if we have a thorough knowledge of what happens on 1G and 0G, then perhaps we can infer what happens during the various stages in between. Not quite the real thing, I agree, but It's a step in the right direction, until Mustard actually gets us to Mars.

VIIP is also a concern.

It is probably worse than we are even thinking for a developing child. If they have brittle bones it isn't just weaker bones, it is bones that can snap instead of flex when force is applied. When born, infant's bones are rather flexible and harden up over time. That may also not even occur. They may remain overly pliable even to the point of being rubbery.

We just don't know, but we know enough not to simply expect a weaker body that is still able to tolerate living on Mars.

>Mars provides nearly half a G

38% isn't 50% You may as well be writing in crayons.

Not really. Microgravity and low gravity are entirely different things. The only way to really test it is to do experiments on mars

>Twelve percentages points short
It's Veeky Forums, so I'll excuse your autism... Nevermind the fact that, much like Earth's, Mars gravity varies a bit from point to point, and seeing as how the icy poles (the highest gravity points) are where you'll likely want your bases anyways...

VIIP is only a thing in microgravity. (And it isn't the largest concern in microgravity, as there's potentially fatal problems involved well before then - namely aneurysms.)

Bone structure will probably develop about the same, as most of that is done while floating in liquid anyways. The hardening of bone isn't gravity dependant either...

What is a problem, is that a lot of what protects bones is muscle, and those aren't going to develop as well in low G.

>The hardening of bone isn't gravity dependent either...
I'm pretty sure it is. The bones are hardened due to healing of micro-fractures that occur every time you hit the ground.

There's isn't one thing you've said that you know anything about. You should probably move onto something a bit more popsci for your level, kid.

Bones generally harden well before babies can crawl (max three months, usually less than one). Unless there's some shit parenting involved, they ain't hitting the ground a lot before then. SFAIK the process is entirely chemical.

As I recall, however, a lot of prenatal development in some animals, especially insects, is dependant on knowing which way is up. I dunno, off hand, how true this is for humans. That might not be a fatal factor at Mars gravity, but if it's true for humans at all, I suspect it'd make any microgravity baby non-viable from the start, and may cause additional issues even on Mars.

I meant it more in a sense that you have you walk to keep up the hardness of your bones. There is a reason why old people break their hips a lot. They walk less, which makes their bones less dense and brittle, which in turn makes them walk less, ad infinitum. Of course their muscles are weaker as well, and when they finally get to walking, they fall and break their bones. So, on a low-gravity world such as Mars, you would probably need to clock in some time at a treadmill everyday to keep up your muscles and to keep your bones dense. NASA's astronauts in ISS have stationary bikes to help them with loss of muscle mass, but they still have iirc 40% bone density loss once they return to Earth and have to take it easy for a while for fear of falling and breaking.

>As I recall, however, a lot of prenatal development in some animals, especially insects, is dependant on knowing which way is up.
Apparently not a problem for making viable rats in space:
indiana.edu/~rcapub/v27n1/rats.shtml
...But there's other problems... Granted, this is zero gravity. Mars gravity likely wouldn't cause the vestibular problem - though a Mars native would likely be as disoriented on Earth as an Earth native would be on Mars. However, there's also those other problems.

Osteoporosis is not caused by a simple lack of walking around. Young folks in comas for years, for instance, don't suffer from brittle bones, just shit muscle. Most old folks simply don't grow new bone quickly enough to outpace the natural bone loss due to chemical imbalances at every level, which affect muscle as well.

Nonetheless, the astronauts on Mir were losing 1% bone mass per month. Granted, that's about the same as you see in the elderly, and less loss than you see in most postmenopausal women.

Bone stress helps to trigger bone growth, so this is a factor. Given that, even in zero-G, the loss can be compensated for, it probably wouldn't be a problem on Mars, for adults... But children, presumably, would be quite another thing.

Astronauts on ISS basically have to workout a few hours every day and still have losses and some semi-permanent losses. It is getting better, but that is merely do to even more exercise. Which leaves them with even less time to do experiments and shit not related to health.

with better exercise machines, could probably fix that
And if they had centrifuges to sleep in
would probably totally fix it

>humans in centrifuges in space

Has this been done yet irl? Just curious. It is like part of most sci-fi stuff that doesn't have magic artificial gravity.

Skylab, kinda, sorta, had a half-assed one as proof of concept.

>Skylab

Shiiieeet, that was a long ass time ago. I totally forgot it even existed. It was like a media circus when it fell. We had 3 channels and it was NOTHING but news coverage of that. So, much god damn nostalgia right there.

That wasn't a centrifuge though, it was just a circular track they would "run" around on.

There's the same thing in the book "Imperial Earth" but it is used for bicycles, if I remember correctly. Neat concept overall.

Yeah, though it served its job as proof of concept, as between the station rotation and the astronaut running, it provided a partial G, and it did actually mitigate some of the health effects of microgravity.

And yeah, I remember that too. Brought tears to my little eyes, though not quite as badly as Challenger did later, even though I was old enough to have "men don't cry" drilled into my head by then. (Man, to go back in time and scream at someone, "The fucking O-ring!")

Shame we didn't have a shuttle program in the 70's - I bet we coulda fixed that crap (gersh dern micrometeorites). Though it'd probably be down by now in anycase.

>Challenger

I didn't even bat an eye when that happened. I think it was because I wasn't into space shit around that time due to school. But, when it happened they had every TV in every classroom on so we could watch it. Everyone was like, "what is this?"

The shuttle program ended in like 2011, fyi. There just wasn't much main stream news coverage about NASA stuff anymore.

More feasible than earth. High gravity + medium thick atmosphere makes the problem difficult.

A space elevator, in theory, would have a much higher cargo capacity than a rocket. And, assuming it's a maglev, it would cut out all fuel needs for ascent. This is would be a very good thing as it would get costs down.

Even then, the biggest gain would be removing the vast majority of potential faults from a mission.

How could it get built?

Like build the base on Mars or other small planet/moon, build everything else in space then lower it to connect to the base? Or, string a "cable" in position and build everything around it?

1. build base
2. build satellite and launch it into geosynchronous orbit over base
3. launch cable, connect it to satellite
4. connect elevator vehicle to cable

The problem is the actual connection: a cable with too much tension will snap, a cable with not enough tension will add "weight" to the satellite, dragging it down.

Add a tension spring to the cable.

>How many billions will a space elevator cost?
Trillions.

>How much will it lift in tonnage per year?
A fuckton. Are you even serious? It's a thirty thousand kilometer long cable with continuous cargo going up and down along its entire length. It may be expensive, but the costs of getting the same amount of shit out of the gravity well by burning two million litres of fuel per launch are orders of magnitude higher. Even with reusable rockets.

>Are you even serious?
Are you? It's gonna take along time to go up the cable, the cable is not going to take much extra weight without breaking, shit going up/down means wear & tear....

And ofc it wouldn't actually reduce the energy needs for launching payloads so you are still burning the same fuel, just in an earthside power plant.

>20XX
>advanced enough technology to build space elevators
>burning fuel to generate energy
confirmed for nonserious

Remember, the subject is not on Earth, but on other planets where the gravity is far lower.

That somewhat implies materials are probably being mined and refined off Earth too. For that level of technology it may be feasible to bring in asteroids for resources and actually build everything in space then lower it down to attach it.

It isn't impossible, it is feasible, but it is improbably that it will happen. We still haven't decided if this will be easier in the long term as opposed to rockets or even mass drivers. I think it really depends on how weak the gravity is. Where is that tipping point where one will be more feasible to use than the other?

Like the Moon doesn't need one, but Mars might.