Artificial gravity in long term space travel

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R

raptorborealis

Guest
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
 
Y

Yuri_Armstrong

Guest
raptorborealis":146al4th said:
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
The point of the discussion isn't really the nomenclature. Saying artifical gravity as an all encompassing term is easy and everyone knows what you're talking about. We already know that you can't create gravity.
 
R

rockett

Guest
Yuri_Armstrong":2t6gjr2k said:
raptorborealis":2t6gjr2k said:
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
The point of the discussion isn't really the nomenclature. Saying artifical gravity as an all encompassing term is easy and everyone knows what you're talking about. We already know that you can't create gravity.
Not necessarily true. Some theories of Quantum Gravity postulate gravitons.
Though creating and manipulating them would be a neat trick, it's not totally out of the realm of possibility.
http://physics.about.com/od/quantumphysics/f/quantumgravity.htm
 
Y

Yuri_Armstrong

Guest
rockett":182vnqt6 said:
Yuri_Armstrong":182vnqt6 said:
raptorborealis":182vnqt6 said:
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
The point of the discussion isn't really the nomenclature. Saying artifical gravity as an all encompassing term is easy and everyone knows what you're talking about. We already know that you can't create gravity.
Not necessarily true. Some theories of Quantum Gravity postulate gravitons.
Though creating and manipulating them would be a neat trick, it's not totally out of the realm of possibility.
http://physics.about.com/od/quantumphysics/f/quantumgravity.htm
Hm, that is interesting. But such technology is not likely going to be even considered for the upcoming missions to the moon/mars/asteroids.
 
R

rockett

Guest
Yuri_Armstrong":2pxeogk4 said:
Hm, that is interesting. But such technology is not likely going to be even considered for the upcoming missions to the moon/mars/asteroids.
Agreed. I was simply objecting to the statement by yourself and others that "you can't create gravity", which is not necessarily true. A better statement would be "not technically feasable in the immediate future" or something similar. (barring any mad scientists or secret government projects :D )
 
Y

Yuri_Armstrong

Guest
rockett":3drmrzz7 said:
Yuri_Armstrong":3drmrzz7 said:
Hm, that is interesting. But such technology is not likely going to be even considered for the upcoming missions to the moon/mars/asteroids.
Agreed. I was simply objecting to the statement by yourself and others that "you can't create gravity", which is not necessarily true. A better statement would be "not technically feasable in the immediate future" or something similar. (barring any mad scientists or secret government projects :D )
That would make for a pretty long topic title. I'm aware that you could maybe create gravity, and the gravity isn't really artificial, but cmon...
 
R

raptorborealis

Guest
rockett":17wnco4m said:
Yuri_Armstrong":17wnco4m said:
raptorborealis":17wnco4m said:
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
The point of the discussion isn't really the nomenclature. Saying artifical gravity as an all encompassing term is easy and everyone knows what you're talking about. We already know that you can't create gravity.
Not necessarily true. Some theories of Quantum Gravity postulate gravitons.
Though creating and manipulating them would be a neat trick, it's not totally out of the realm of possibility.
http://physics.about.com/od/quantumphysics/f/quantumgravity.htm
Where in quantum mechanics is there any theory about 'creating' gravitons? there is some debate about their existence (if at all) but that is not 'creating' them. Add two masses together and you have added the gravitational force but you haven't increased total gravity by creating a graviton.
 
R

raptorborealis

Guest
Yuri_Armstrong":6ecd1kjw said:
raptorborealis":6ecd1kjw said:
Again,

There is no such thing as 'artificial gravity' There is gravity and there are other forces.

Gravity is just gravity. One can employ other forces to counter some impact of gravity but the gravity still exists....and one can't 'create' gravity. All one can do is to use the forces that exist and combine them in some way to achieve a purpose. An object can fall to the Earth, an object can orbit the Earth, or an object van escape from the Earth. The force gravity of the Earth on the object is identical in every case...it is the other forces that are the changing variable.

One doesn't alter the gravity one iota by spinning a space craft, etc. One adds other forces into the equation. The gravity does not change. We have zero impact on increasing or decreasing gravity. We can only counter the effects of gravity.
The point of the discussion isn't really the nomenclature. Saying artifical gravity as an all encompassing term is easy and everyone knows what you're talking about. We already know that you can't create gravity.
I take it you do not have a scientific background. ...' everyone knows what you're talking about' Quite the statement on a so-called science forum.
 
R

rockett

Guest
raptorborealis":xt7ticqh said:
Where in quantum mechanics is there any theory about 'creating' gravitons? there is some debate about their existence (if at all) but that is not 'creating' them. Add two masses together and you have added the gravitational force but you haven't increased total gravity by creating a graviton.
Welllllll Mr raptorborealis, while I was speaking metaphorically, you seem to want to take it to a more technical level. While yes, I know that there is some debate about their existence in the physicist community, at this point the evidence is not conclusive either way (though the LHC might change that).

So, I will let you explain your statement in detail...
 
U

uberhund

Guest
I concur with Yuri, Raptor, or anyone else flatly stating that "you" (meaning Rockett) cannot create gravity. Ok. Maybe it's just me. But don't feel bad, Rockett. Nobody else can either. Except in the movies. And I bet they use gravitons.

The obvious approach of overcoming the effects of weightlessness during inter-planetary space travel through spinning something, toroidal or otherwise, is futile - for medical, economic, and engineering reasons. To reproduce the essentials our bodies require from gravity through rotation of a space ship (long term space travel - the title of this thread) is a complete non-starter.

Let's focus our resources on real science - sending probes and rovers to Triton and Europa.
 
K

kelvinzero

Guest
uberhund":2bd6a5g0 said:
The obvious approach of overcoming the effects of weightlessness during inter-planetary space travel through spinning something, toroidal or otherwise, is futile - for medical, economic, and engineering reasons. To reproduce the essentials our bodies require from gravity through rotation of a space ship (long term space travel - the title of this thread) is a complete non-starter.
Please supply your evidence for such an extraordinary claim. It better at least be something published.
 
Y

Yuri_Armstrong

Guest
raptorborealis":1pgl5anr said:
I take it you do not have a scientific background. ...' everyone knows what you're talking about' Quite the statement on a so-called science forum.
I already told you why I called it artifical gravity. It really doesn't matter either way so let's just drop it.

I concur with Yuri, Raptor, or anyone else flatly stating that "you" (meaning Rockett) cannot create gravity. Ok. Maybe it's just me. But don't feel bad, Rockett. Nobody else can either. Except in the movies. And I bet they use gravitons.
Well it's all pretty speculative. He was just saying that to further the argument on the title of the thread I think.

The obvious approach of overcoming the effects of weightlessness during inter-planetary space travel through spinning something, toroidal or otherwise, is futile - for medical, economic, and engineering reasons. To reproduce the essentials our bodies require from gravity through rotation of a space ship (long term space travel - the title of this thread) is a complete non-starter.
How is it futile? It's been proven that it can be done. The medical and engineering problems have been solved, and I assume by economic you mean "getting funding", well that's one every space mission requires. This would be nothing new.

Let's focus our resources on real science - sending probes and rovers to Triton and Europa.
This is REAL science. A manned mission can do many more science experiments and bring back a lot more samples. Plus we need to learn how we can live away from Earth for long periods of time. Robotic probes are good but they are really just scratching the surface. We've been sending probes throughout the solar system for decades and still don't have anything conclusive on life elsewhere. If we send astronauts we can gather a lot more information on these other worlds.
 
U

uberhund

Guest
Kelvinzero writes:
Please supply your evidence for such an extraordinary claim.
A claim that pigs can't fly is not extraordinary. A claim that pigs can fly would be extraordinary.
(This flying pig metaphor came to mind while I was pondering the flight characteristics of the STS, and its extraordinary failures in meeting original operational goals)

Kelvinzero continues:
It better at least be something published.
Well, Newton and Einstein are rather well published. However, a more constructive exercise might be to categorize the list of the salient obstacles (economic, medical, and engineering) to long term space flight for humans. This would at least provide a road map for those who believe it worth pursuing.

For this exercise, I would also propose a fourth category: ethical.

For example, it might be possible to genetically engineer a flying pig, but is it ethical?
 
J

James_Bull

Guest
uberhund":7t5827ky said:
Kelvinzero writes:
Please supply your evidence for such an extraordinary claim.
A claim that pigs can't fly is not extraordinary. A claim that pigs can fly would be extraordinary.
(This flying pig metaphor came to mind while I was pondering the flight characteristics of the STS, and its extraordinary failures in meeting original operational goals)

Kelvinzero continues:
It better at least be something published.
Well, Newton and Einstein are rather well published. However, a more constructive exercise might be to categorize the list of the salient obstacles (economic, medical, and engineering) to long term space flight for humans. This would at least provide a road map for those who believe it worth pursuing.

For this exercise, I would also propose a fourth category: ethical.

For example, it might be possible to genetically engineer a flying pig, but is it ethical?
5 pages later and you still have yet to back up any of your extraordinary/mad/insane claims. All you have done is reply with more irrelivent tripe! Are you a wind up or something?!
 
S

SteveCNC

Guest
Interesting , I can't recall reading where Einstein ever even mentioned using cetrifugal force as an artificial gravity to over-come the problems related to long term weightlessness and I'm pretty certain Newton didn't mention it either . If you think it would cause too much strain to the structure your in when spinning at even 1g I don't believe that is a problem at all providing that's what it was engineered for . So what exactly is it you think is going to happen anyway Uberhund ?
 
U

uberhund

Guest
Ok. I’m not feeling the love here. But I get it. Dreams die hard. And no one likes a dream killer.

But science is hard too. Math is cruel. This is why we don’t have, and never will have, C3PO-like autonomous humanoid robots, and jet pack rocket belts, and hover boards, and interplanetary space travel for humans. It’s not rainbows and unicorns out there. It’s the combination of obstacles that kill these dreams. Not me.

Some examples (or tripe, depending on your point of view):
  • Yes, it’s possible to put humans on an interplanetary trajectory, but without shielding, it’s not ethical, even if the crew knowingly volunteers to die in space.

    It’s possible to surround a space ship with concrete and electromagnets to reduce radiation hazards, but energy densities of chemical and ionic propulsion will not propel the resulting mass to interesting, inter-planetary speeds. This is the periodic table of elements speaking, not me.

    It’s possible to generate thrust using atomic/thermonuclear energy, but it’s not ecological nor economic. Consider, for example, the crushing cost of building and maintaining and keeping nuclear reactors safe here on Earth. What government would agree to pay these costs for rewards that may or may not accrue only after everyone who contributed to the funding is dead?

    It is possible to use planetary and stellar gravity assists for acceleration, but the time frames involved would require multiple generations of travelers to be born on the space craft. And that would not be ethical. That's it. There are no other practical forms of propulsion.

    It would be possible to remove some constraints on human space travel were light speeds achievable. Unfortunately, energy densities are too low to accommodate the required acceleration profiles (Newton) and the increase of mass will null out the increase in velocity (Einstein).

    It’s possible to send humans to Mars, but probes and rovers will be returning samples sufficient for proving the existence of life-precursors on Mars in the next four or five years without having to expend resources on any of the obstacles (or tripe for those on Planet Unicorn) itemized above.
 
V

Vlad_Dracul

Guest
scottb50":326oerp3 said:
SteveCNC":326oerp3 said:
While I am certain you can't get even close to 1G acceleration however virtually any acceleration/deceleration would create an artificial gravity . It dosen't have to create much , just enough to get a sense of up and down and make objects fall toward the floor .

It would keep my cereal in the bowl while I ate .
Thrust is rated in the thousands of a G, I doubt that would keep your cereal from roaming.
DANG IT!!! I was all about going to Mars, but if I can't eat my Captain Crunch along the way, just count me out!!!

:(
 
S

SteveCNC

Guest
I'm still at a loss as to why you don't think centrifugal force to create an artificial gravity will work Uberhund ?

I'm not trying to be mean or anything , I mearly want to understand your point of view on that particular subject . What is it about using one force to approximate another that can't/won't work ? To me it seems rather simple and once your spinning it should take very little energy to maintain the spin at the correct speed .

The space race to date has mostly been about figuring ways through or around problems and the problems associated with weightlessness are just another problem to be solved like all the others before that . My son tends toward being a pessimist but more often than not he get completely surprised when I point out the flaw in his logic and show him the solution . Pessimists have a bad habit of encounterring a problem and throwing their hands up claiming it must be impossible then the next day someone does it , proving once again being a pessimist is foolish , you can't create anything new when you close your mind to other possibilities .
 
R

rockett

Guest
SteveCNC":2y6puda2 said:
I'm still at a loss as to why you don't think centrifugal force to create an artificial gravity will work Uberhund ?
I have to agree with you SteveCNC, that contention really doesn't make sense.
I posted this on Gravitiy space stations http://www.space.com/common/forums/viewtopic.php?f=15&t=25693 but in hindsight I should have posted it here. Both ESA and NASA are looking at this confguration for a Mars mission spaceship:


http://www.nasa.gov/vision/space/travelinginspace/keeping_astronauts_healthy.html

What is SO HARD about this idea? Engineering wise it should cause no ill effects on the crew...
 
Y

Yuri_Armstrong

Guest
uberhund":18w752cy said:
Ok. I’m not feeling the love here. But I get it. Dreams die hard. And no one likes a dream killer.
No, we just don't like it when people don't pay attention to proven engineering concepts.

But science is hard too. Math is cruel. This is why we don’t have, and never will have, C3PO-like autonomous humanoid robots, and jet pack rocket belts, and hover boards, and interplanetary space travel for humans. It’s not rainbows and unicorns out there. It’s the combination of obstacles that kill these dreams. Not me.
Here you're trying to use the "giggle factor" to prove your argument. Nobody was talking about androids, hover boards, or jetpacks (and if you did a bit of research you would see that such things are possible, just not common or economically feasible). The universe has presented many challenges to spaceflight, manned and unmanned, but our talented scientists, engineers, astronauts, and other have all found ways to work around them and achieve what was once considered to be impossible science fiction. Your argument reminds me of those who used to complain that trains were noisy, dangerous abominations and that speeds above 30 mph were rip people to shreds.

Some examples (or tripe, depending on your point of view):
  • Yes, it’s possible to put humans on an interplanetary trajectory, but without shielding, it’s not ethical, even if the crew knowingly volunteers to die in space.

  • What space program would send their astronauts on a mission without proper shielding? Nobody is even mentioning such a thing.

    It’s possible to surround a space ship with concrete and electromagnets to reduce radiation hazards, but energy densities of chemical and ionic propulsion will not propel the resulting mass to interesting, inter-planetary speeds. This is the periodic table of elements speaking, not me.
    You're suggesting the bulkiest and heaviest materials for radiation shielding though. There are other ways to protect a spacecraft during flight. Water and ice serve as excellent protection from radiation for example.

    It’s possible to generate thrust using atomic/thermonuclear energy, but it’s not ecological nor economic. Consider, for example, the crushing cost of building and maintaining and keeping nuclear reactors safe here on Earth. What government would agree to pay these costs for rewards that may or may not accrue only after everyone who contributed to the funding is dead?
    A mars mission would not require entire countries to build whole new nuclear plants for its thurst. If you are talking about for interplanetary travel to become routine, those nuclear plants could be built on the moon where there is no ecology to disturb. The moon also has helium-3 deposits which are key for nuclear fusion research.

    It is possible to use planetary and stellar gravity assists for acceleration, but the time frames involved would require multiple generations of travelers to be born on the space craft. And that would not be ethical. That's it. There are no other practical forms of propulsion.
    Stellar assists? maybe. But planetray assists? The voyager probes used planetary assists in the late 70's and today they are at the edge of the solar system. It wouldn't take generatons to use gravity assists, and that's not the only way of propulsion anyway.

    It would be possible to remove some constraints on human space travel were light speeds achievable. Unfortunately, energy densities are too low to accommodate the required acceleration profiles (Newton) and the increase of mass will null out the increase in velocity (Einstein).
    This is common physics knowledge and nobody was suggesting that we travel at or above the speed of light.

    It’s possible to send humans to Mars, but probes and rovers will be returning samples sufficient for proving the existence of life-precursors on Mars in the next four or five years without having to expend resources on any of the obstacles (or tripe for those on Planet Unicorn) itemized above.
[/quote]

Nonsense. Manned missions can do a lot more science work than probes. We've been sending probes to other planets for decades yet they still can't confirm or deny existence of life on these other worlds. Manned missions can deploy more experiments, collect more data, and bring back a lot more samples than any robot can. If your true interest is in the science of the other planets, then manned missions are what you want to look at because that is what will bring you the most information.
 
R

rockett

Guest
Yuri_Armstrong":b7fbrhon said:
uberhund":b7fbrhon said:
Ok. I’m not feeling the love here. But I get it. Dreams die hard. And no one likes a dream killer.
No, we just don't like it when people don't pay attention to proven engineering concepts.
I have to agree with you Yuri. Unfortunately there are a LOT of pessimists out there too. I'll bet if they had their way, the US would never have existed either. DREAMS ARE important, though. Look at how much real science and discoveries that are very real today, that started out as Sci Fi.
 
F

Floridian

Guest
Yuri_Armstrong":2n4be4g2 said:
SteveCNC":2n4be4g2 said:
I am sure it could be done although the radius of the swing at floor level would have to be fairly large to not get dizzy I would think . I guess as long as the entire ship spun you wouldn't have to worry about creating air-seals that could handle rotation while maintaining pressure .

I always though that some type of constant ion propulsion (accelerating or braking) would be good for creating a weak artificial gravity and while it wouldn't help a lot for maintaining bone density it would provide enough gravity to be able to move around normally and even eat and cook in a semi normal manner because you would have a sense of up and down .
I don't think astronauts really have trouble with orientation and up and down and stuff like that. I think really the only purpose of artificial gravity is to keep the crew in decent health.

I'm not talking 1 G here, more like .30-.40 gs so the crew can become accustomed to Martian gravity. The spinning part of the ship would need to be big enough so the crew wouldn't become dizzy or nauseated. Is there an engineer here who could explain what would be necessary for this?

Also, is there another way to possibly create artificial gravity? The only other way I could think of would be building a huge space "globe" that the crew could live in, which generates a gravity field of its own. That idea is generally used for interstellar travel though, not interplanetary.
As for the large radius problem, once the ship was en route, what you could do is have a living module attached to a beam that came out of the ship. Take the ship as an egg, well the sides of the egg would both shoot out about 500 feet or whatever and would only be attached by a pole/beam.

see this video

http://www.youtube.com/watch?v=V1vKMTYa ... re=related
 
U

uberhund

Guest
SteveCNC wrote:
…being a pessimist is foolish..
Pessimists may be lonely, but I’m not so sure they’re foolish, or even unnecessary to the creation process. In fact, I wish there were more of us, particularly in the midst of those who believe the Moon landings were faked, or that UFOs and aliens are abducting people.

After all, out of conflict, emerges truth. Would there be any truth emerging in science were it not for skeptics? Galileo comes to mind.

Some Nigerians might choose an honest living if there were more email scam skeptics. We might also finally see the last of John Edwards seances or Kevin get-rich-at-home Trudeau infomercials.

On the other hand, I’m eager to learn that parents, such as you, are encouraging kids to dream, and to combine science, math, and art into beautiful, elegant, novel solutions. Our schools are doing a terrible job at inspiring kids, at all levels.

Rockett wrote:
What is SO HARD about this idea? Engineering wise it should cause no ill effects on the crew.
First of all, I really enjoyed your graphic. Thanks for sharing it. I admit it would be exciting to be part of that project. I could even imagine myself volunteering to be on the crew. But then, I thought the Grumman luner lander was beautiful too. Seriously. It bucked Hollywood, and conventional thinking, and it worked. Six times. Beautiful.

But you ask what's so hard: It's not the single concept, but the combination of obstacles to make it real. As aerospace engineers are fond of pointing out, you don’t go into space on PowerPoint slides. If you won’t buy into the engineering obstacle, perhaps you will consider the economic obstacle that governments and wealthy individuals won’t buy a fleet of Mars spinners.

There can't be just one. There will have to be a fleet.

Consider this: There was a reason Columbus chose three ships to cross the Atlantic. It was the same reason the pilgrims chose, wisely it turned out, to voyage to the New World in a convoy of three ships. It took ten versions of the Apollo stack before the one that actually landed. The excellent Mars rovers were sent in pairs for the same reason.

So when you’re buying a Mars machine, you’re actually building, at a minimum, three:
1) Mars 1: Testing in Earth and lunar orbit
2) Mars 1a: Refit Mars 1 for testing around Mars in automated robotic mode, with an automated robotic lander and return vehicle (obviously bringing home samples along the way). The mission will take years, so Earth has plenty of time to build the remaining two vehicles.
3) Mars 1b, 2, and 3: Refit Mars 1a for the real deal and call it Mars1b. Mars 2 and Mars 3 will voyage with humans to Mars. Mars 1b, possibly 10 years old with a lot of miles on its odometer now, remains home "in the barn" or in a free-return orbit for emergency use in the event the Unicorn Drive blows up on Mars 2 or 3. Unlike Apollo, there will always be a backup for modern space travel. Mars 2 and 3 will serve as backups for each other, and plunder each other as necessary for spare parts.
4) Legislators will look at the cost of three vehicles and be voted out of their precious offices for even considering participation in the program because samples of Mars will have been returned by robots a decade earlier, from which not a single taxpayer will have ever seen a single dime. Evidently, tax payers don't appreciate dirt, no matter what the origin.

But Mars is unique. It's close. I'm not saying it can't be done. I'm saying it musn't be done. The money is better spent elsewhere. Ok. I take it back. I'm saying it can't be done so it doesn't matter if we musn't.
 
S

SteveCNC

Guest
uberhund":td8aeodt said:
But you ask what's so hard: It's not the single concept, but the combination of obstacles to make it real. As aerospace engineers are fond of pointing out, you don’t go into space on PowerPoint slides. If you won’t buy into the engineering obstacle, perhaps you will consider the economic obstacle that governments and wealthy individuals won’t buy a fleet of Mars spinners.
I'm still curious what this elusive "Engineering Obstacle" actually is , obviously I'm not seeing something you think you are . Granted I've only worked in the aerospace manufacturing field for 33 years and seen most type of rockets from the inside out , but as far as I can tell there is no engineering obstacle at all in fact it would be quite simple to set it up , after all these things were pulling 12g's getting up there they can certainly handle 1g worth of spin . Guidence systems wouldn't be hard to program to control the spin rate , even balance would be easy to maintain . With the entire ship spinning there's no need to deal with a spinning airseal . I wouldn't want to ride at the pivot point for very long but there shouldn't be a need to do so except during an emergency maybe . That's when I'll be saying "damn I wish someone had invented a better barf bag , this paper thing sucks" :roll:

The economical side is a political game for the most part at least if nasa is to do anything but it's hard to say where that will go in the future , every president seems to have their own agenda so nasa seems like they are always in some sort of flux . Back in the day of ships they may have done 3 but that's because those ships didn't have redundant systems like Apollo on up , and any ship going to Mars will have them as well . A ship going to mars would be like 3 ships in one because of the redundant systems possibly even a 4th life support system so yeah our ships are build a little better than the Nina,Pinta,Santa Maria .
 
U

uberhund

Guest
Yuri writes:
Manned missions can do a lot more science work than probes.
Here’s where the combined skills of the people in the forum could blaze some interesting trails: Are the contributions of any endeavor, measurable? For example, were the data collected by the Ranger missions less valuable than the rocks returned by the Apollo crews? I dunno. But I believe there must be a way to rigorously compute this. Would it be something like:

(cost of mission) / Sum of (factoids discovered) = cost per factoid?

But this isn’t quite right either, because one factoid could cure cancer, and another could only cure, say, acne. But I’m intrigued with the idea of putting rigor into the common proclamation that manned missions do more work. Remember that we had twelve humans on the Moon, and their on the scene CSI completely overlooked the presence of water. That discovery was made by a probe.

Focusing on the last decade of astonishing scientific discovery, my sense is that the probes and rovers contributed Alexandra-library quantities of valuable data compared to whatever they’re supposedly doing on ISS (when they’re not repairing the air conditioner, or amusing themselves coaxing floating globs of food into their mouths, or sending their crew off in diapers to avenge a love triangle).

But I could be wrong. I've been wrong before. My apologies for the long post to your thread, Yuri.
 
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