NASA Pondering L2 Outpost, Return To Moon 122
New submitter Joiseybill writes "Now that the election is over, any voters that may have been influenced can rest easy. Space.com reports that the agency has been 'thinking about setting up a manned outpost beyond the moon's far side, both to establish a human presence in deep space and to build momentum toward a planned visit to an asteroid in 2025.' Space policy expert John Logsdon said, 'NASA has been evolving its thinking, and its latest charts have inserted a new element of cislunar/lunar gateway/Earth-moon L2 sort of stuff into the plan. They've been holding off announcing that until after the election.' According to the article, 'Rumors currently point toward parking a spacecraft at the Earth-moon L2 gateway, so NASA (and perhaps international partners) can learn more about supporting humans in deep space. Astronauts stationed there could also aid in lunar exploration — by teleoperating rovers on the moon's surface, for example.'"
Old news... (Score:2)
Re:Old news... (Score:5, Informative)
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Either way space cows ASAP.
Re:Old news... (Score:4, Interesting)
Getting time to leave.
Re:Old news... (Score:4, Interesting)
Re:Old news... (Score:5, Funny)
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Newborns are great in inventing acronyms; ISRU, LSSPO, ABMA, ARGMA, AOMC...
Budget (Score:1)
Does the congress have a budget for this kind of thing...? Considering they are doing quite a lot of cuts.
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NASA's budget is going to be cut due to sequestration anyway, so the answer is ultimately no. Even cutting money wasting abominations like the James Webb Space Telescope (a good idea, just extremely lousy in terms of implementation) and the SLS ("Senate Launch System") program won't really pay for anything like this.
Then again the U.S. federal government is headed for a fiscal brick wall anyway. NASA may not survive the fallout from that when it ultimately hits.
None the less, it is good to be thinking abo
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ESA does not consider James Webb to be a waste of money, and have been keeping up with their part of the bargain for the project. ESA have been getting very annoyed with NASA's funding problems. They do not like allocating hundreds of millions of euros into a project and then finding out that it was all wasted because an international partner couldn't complete their part.
It's already policy for ESA to deny NASA anything but the most trivial of partnerships in any new project. If Webb was scrapped, that poli
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They do not like allocating hundreds of millions of euros into a project and then finding out that it was all wasted
You are ignoring the criticism if you think it requires a partner not throwing money at this project to figure out that its a waste.
The current cost projection is US$6.8 Billion (~5.3 billion euros.) If the ESA doesnt admit by now that it has been and will continue to be money wasted, then the ESA is as corrupted as NASA.
The fact that you don't see it means that you really have no idea how much money that is. Thats about 4 times as much money as it took to develop the space shuttle, a god damned re-ent
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The fact that you don't see it means that you really have no idea how much money that is. Thats about 4 times as much money as it took to develop the space shuttle...
You have your numbers wrong and you're also forgetting about inflation! The JWST program will cost a fraction of the Shuttle's development costs! The Space Shuttle cost $6.744 billion [wikipedia.org] to develop, but that's in 1971 dollars -- today, that would be $38.5 billion dollars, according to "usinflationcalculator.com".
Don't forget that the JWST is a seriously high-tech device, with many entirely new or never-before-tried technologies required. Much of the cost is R&D, not manufacturing or assembly. In contrast,
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Which part of this is confusing you?
The hilariously low estimate of $500M.
That's much lower than the Hubble cost, which was a much simpler telescope.
Interestingly, the Hubble cost $2.5B to develop and had a total operating cost of $10B, but the original estimate was $400M, which is similar to your $500M figure.
It's likely that what happened in both cases is a symptom of big government contract negotiations: bid insanely low to win the contract, and then keep adding "cost overruns" until you get the actual amount of money required.
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The issue with the Jame Webb Telescope is one of misappropriations of money and a lack of a plan. The management of the program has been absolutely horrible, If you go back into earlier threads here on Slashdot about this program, not to mention on other forums that talk about how it is being managed, it is really more of a domestic jobs program for research scientists than much of an actual program for going into space and doing something useful.
I say it is horribly mismanaged because the program lacks f
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Perhaps we should start a Super Pac...
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By Atheismo's great shaven face! I would so donate every discretionary cent to a SuperPAC set up to force congress into funding NASA better!
I'm not being sarcastic, quite the opposite. Although, a SuperPAC would probably just waste all the money on slandering JAXA and the ESA in order to make NASA look like the only electable cadidate XD
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Why launder the money through Congress? Their 'convenience' fee would be better spent directly supporting your favorite organization.
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Does the congress have a budget for this kind of thing...? Considering they are doing quite a lot of cuts.
Can the congress balance a budget for this kind of thing...?
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Travel to a Earth-Moon Lagrangian point is really no harder than going to the Moon. I don't know why there would be any special alignment or other issues related to travel to the Lagrangian points, other than perhaps there might be some sort of Aldrin cycler [wikipedia.org] between the Earth and the Moon for a low-energy transfer system of bulk supplies. Note the link is in reference to such a "cycler" between the Earth and Mars, but a similar system could be put between the Earth and several Lagrangian points or even th
Re:NASA interns research project (Score:5, Informative)
L2 is actually significantly easier than going to the Moon, assuming you want to stop and not just crash. You need to expend fuel to slow you down in the Moon's gravity well, and for L2 you do not. Relative to the Earth, the Moon and L2 are very close in energy to reach, not counting the gravity well.
Again with the manned space mission insistence (Score:1)
Given the budgetary constraints that will exist for about the next 10 years, it is ludicrous to continue insisting on manned space missions. An L2 way station, as well as multiple way stations on the way to Mars can only be affordable and practically achievable for unmanned missions. Even then it will be a struggle to keep such projects funded.
The presence of humans adds essentially nothing of practical utility, and certainly nothing whatsoever of scientific utility. Its sole enormous contribution is expens
Re:Again with the manned space mission insistence (Score:5, Insightful)
The role of a human on a science mission is to provide a way to rapidly react to situations at the location and to give very short instructions to perform complex tasks or for somebody 'on the spot' to make some sort of judgement call in terms of what to do next in a time critical situation. I wouldn't call that a lack of utility, but it is a narrow set of situations where early exploration science missions admittedly don't need to have those kind of parameters.
Right now there is still a whole lot of low-hanging fruit in terms of things that can be done with robotic spacecraft, so I would have to agree that some sort of increase in spending for robotic missions is warranted even at the expense of manned spaceflight. Then again you have projects like the James Webb Telescope that have been sucking up even the money that could be spent on other deserving robotic missions, so demonizing the manned spaceflight program really shouldn't be the only target here. More intelligent and fiscally responsible spending should be happening in this area.
None the less, when Harrison Schmitt was on the Moon, he was able to perform the kind of scientific analysis on the spot that simply couldn't have been done by a robotic probe. There really is a need to send up some geologists to the Moon to perform a really extensive survey of lunar materials and to follow up on previous scientific research that has been done there. The kinds of things that a robotic vehicle could do on the Moon would be significantly limited without having somebody on site able to really perform the kind of science that needs to be done there.
Carl Sagan performed a major disservice to America by making it a manned vs. unmanned mission argument anyway. The reasons and needs for either really have separate motivations and objectives, other than robotic missions are really good for doing the early preparatory work needed to make manned missions successful.
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My argument has nothing to do with Carl Sagan. It is purely a cost issue, and the far greater expense of manned space flight limits space exploration overall.
I understand your argument, but "on the spot" analyses are rarely needed, and missions like Curiosity will be very productive without them. I can't see any practical justification for manned space missions today. This will likely be the case for decades. Slowly building way stations for gradually more ambitious robotic missions to Mars, the asteroids,
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humans make pretty good robots for surface exploration
I don't know any human who could fly to Mars without food and air for a year, then be dropped to the surface with 20G deceleration, then pick himself up and walk around for two years while sending detailed images of the planet to Earth via a transmitter in his backpack, and living all this time on solar power alone. That human also has to be suicidal because he will be abandoned on that remote planet.
A human researcher is needed only if the communic
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A human researcher is needed only if the communication link to Earth is unacceptably slow. But even that can be dealt with by sending smarter robots. A human does not have built-in hi-res cameras or chemical labs or lasers in fingers. Robots do. Who is better now?
The human. What you're saying is that the human has a little overhead and requires a little better handling so you need to pay more upfront. But in turn you get a lot more capability.
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You would need to quantify that increased capability though, and not just assume it is much bigger.
Apollo missions do a good job of that. Roughly two weeks on the Moon between six missions and each of the last three rover missions covered as much ground as a MER mission did. Plus almost 400 kg of sample return.
In the literature, long term missions, on the order of two years seems to be the norm for two way missions with a crew of four people and copious energy sources. Let's say that half their time can be spent on scientific pursuits. So I see at least two orders of magnitude more science that can be
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That matters because the huge hidden cost of space science is the idling of Earth-side science infrastructure.
Then you are argiung against your own position. Human spaceflight is not just far more expensive; it is plain impossible at the moment if you think of Mars. Nations of the world are struggling with financial crises; this is not a convenient time to launch a few meatbags on a two-year trip to Red Planet. The trip may also kill them; that won't be good for popular support of space missions.
You ar
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Then you are argiung against your own position. Human spaceflight is not just far more expensive; it is plain impossible at the moment if you think of Mars. Nations of the world are struggling with financial crises; this is not a convenient time to launch a few meatbags on a two-year trip to Red Planet. The trip may also kill them; that won't be good for popular support of space missions.
Not at all. It's definitely feasible within the next 50 years (I'd say 20 years or less myself, but nobody seems to be that much of a hurry). And robotic missions don't seem to be likely to do much in the meantime.
You are asserting that humans can make decisions on the spot. But practice shows that there is no need for such decisions. Robots report back; scientists drink coffee in the safety and comfort of their offices and look at the data. Then they issue new orders to the robots, until the pnenomenon is understood.
So days might be spent figuring out something that an on site human could have figured out in a few minutes? I can't imagine why you think there's no need for vastly faster and more responsive exploration of Mars's surface. We don't live forever, you know.
A modern planetary research robot is basically a wheeled platform with equipment and a decent radio link. No human would be able to carry all that, so if we send a human then the robot will be still present.
Most of the equipment can be stored in a c
Re:Again with the manned space mission insistence (Score:5, Insightful)
Humans will not go to Mars or any other location in our solar system for decades, possibly a century or two. They probably will rarely if ever go to the moon in our lifetimes. The money and justification are simply not there. We have a historic responsibility to play our role and leave the rest for future generations to each play the role that corresponds to them.
The reason why it will take decades or even centuries in order to put people on Mars or elsewhere in the Solar System has nothing to do with money, but simply the will and having governments permitting people to be able to go there in the first place. Money and justification is not an impediment.
One relatively cheap and easy way to encourage development of space economically is to simply say over the next century that any activity which takes place primarily in space is exempt from any form of taxation. Providing liability wavers would be something else that doesn't cost money but would make a huge difference for activities in space as costs could be a whole lot more predictable. The same could be said about simply making some sort of sane type of space law where things like ownership of resources obtained or manufactured in space could be made much more certain. There are people who are willing to go into space and to do things on their own dime, so it really doesn't need to cost anything from a government perspective, and if people can make money they will pay whatever it takes to get there.
Besides, I think the current approaches for getting into space are far too overpriced and other methods for getting into space can be done much more cheaply, even if ultimately it is exploding the equivalent amount of energy of a small nuclear bomb under your chair to put yourself or at least a metric ton of "stuff" into orbit. Cost is even less of an issue in terms of moving stuff around that is already in interplanetary space (aka extracting resources from asteroids). A couple of companies are currently in the process of setting up the infrastructure to do just that.
If you are asking if the USA or for that matter any other country in the world (or even group of countries) has the money to put together a government boondoggle that is a Manhattan Project-style "waste anything but time" mission that would put a bunch of people on Mars, I'd have to agree that such money simply doesn't exist. The Apollo missions were pretty much the most that could be done using such a fiscal model. That isn't exactly true, as the money dumped into the wars in Iraq and Afghanistan could have easily supported such a mission and have done it in under a decade. But it would be in the trillion dollar range none the less and it wouldn't be done in the name of science. If any science actually was accomplished, it would be an afterthought and not the purpose of the mission. I would dare say that spending that kind of money on a "stimulus" program instead of the junk that it was spent on non-military spending (appropriations above and beyond the normal budgetary process mind you as well) could have paid for such a mission as well.
I just simply reject the notion though that we must scale back our dreams. Some creativity in terms of how to finance these missions could happen, but I also am suggesting that even framing the debate in terms of manned vs. unmanned missions and that you can only have one or the other is simply the wrong approach to be taking at all. If it makes sense to send robots and to do something useful, send them. There are separate reasons though to get people into space as well, and if they are going to be on the frontier of human experience they might as well be doing some science too.
America as well as several other countries from around the world have scientific bases set up in Antarctica... at rather significant expense I might add too. If robotic missions were so wonderful, why do you think people are at those research locations instead of tele-operated robots? Note that there are teleoperated robots in Antarctica as well, so it isn't an either-or proposition. I'm just asking you to justify your logic in light of a similar situation that exists perhaps a little closer to home.
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Providing liability wavers would be something else that doesn't cost money but would make a huge difference for activities in space as costs could be a whole lot more predictable.
Liability wavers? What do you think this is, offshore drilling?
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Liability wavers? What do you think this is, offshore drilling?
No, drilling for petroleum offshore is wimpy stuff compared to mining Platinum out of an asteroid. We are talking real he-man, dangerous stuff here where frankly it isn't even known what dangers might be in store for those going into space doing this stuff.
The reason why state and national legislatures put in liability wavers on some activities is because it is seen as something important for national goals and interests, just like offshore petroleum extraction can be for many countries. Your analogy to s
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I may have been too snide: I agree with you! In fact, seeing how offshore drilling has had decades to mature I no longer think that that particular activity should be granted impunity any more. Instead, the guarantees assuring financial insurance for the offshore drilling industry should most certainly be redirected to the newer, riskier technologies that we need, be it asteroid mining, fusion, or something else.
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And while commercial interest is a way to get space exploration for "free" in a sense, something fundamentally has to change. Either we have to find something out there we don't know of now, or there has to be a sudden change in demand for something we do know is out there. As is, what we know is out there wouldn't be economical to collect without transportation costs dropping by several orders of magnitude from even optimistic projections of commercial space flight (as in, not compared to current government space flight costs). It is going to take more than a tax break to cross that gap.
I understand skepticism about commercial spaceflight opportunities, and cost is a huge factor for much of what can be happening in space. A sad reality is that the cost of going into space has been until the past couple of years (due to SpaceX and several other very disruptive companies entering the market) going up in price even faster than inflation.
There are some reasons for that, and it should be noted that commercial spaceflight opportunities have been fleeing from America to the point it was a non-ex
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As much as we should be doing more unmanned missions, there is one thing that unmanned missions have been very bad at: sample return. The reason is simple. Robotic probes are expendable, humans aren't. Also, landing safely on the Earth is harder than launching safely from the Earth. Samples return with the humans, in missions that are already required to land safely. Harrison Schmitt wasn't just able to do "scientific analysis on the spot", he was a geologist who could quickly identify the best samples to r
reason for going to the moon... (Score:5, Interesting)
Often, I hear people demanding to know what practical reason humans would have to travel to the moon again. Many people bring up pipedreams like space ports, or lunar mining complexes.
I have a better reason.
The moon is tidelocked with the earth, has a very stable orbit, and a fairly large circumference. We should put an interferometric space telescope on the dark side of the moon. We could then use the entire circumference of the "visible/invisible" hemisphere terminator zone as the effective aperature size, and be free of atmospheric distortions.
The kinds of pictures we could get from such a telescope would make hubble look like a cheap webcam in comparison.
Put the command/control antenna on the visible side of the moon, and have it garanteed to always be pointed at the earth.
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Re:reason for going to the moon... (Score:5, Insightful)
Putting the parts there, no.
Assembling them and testing all the moving parts? Yes.
Rovers and robots are very robust things, but that level of assembly requires humans still.
Once built, it wouldn't need humans anymore, except for the occasional maintenance or upgrade mission, but the benefits of having it up there would be astounding.
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Tend to agree. Or, if there are parts that are just too bulky to withstand launch you could assemble them in LEO, and then drop the whole thing onto the moon (descending on rockets is pretty gentle).
A relay satellite could be used for communication, or you could stick some microwave relay stations on the surface, though with the moon being so small I'm not sure that you'd get much horizon which would mean more stations.
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Rovers and robots are very robust things, but that level of assembly requires humans still.
Nah, we [where I work that is] do this with robots already thousands of feet under the surface of the sea! Only difference is the ping time.
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If we don't leave, we will surely all die here.
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No, but perhaps those a few million generations removed from us might - and the moon won't do them any good either.
No harm in working out how to get off the planet, but that gets cheaper the longer we wait, and if you want to actually lift the entire population of the planet to go someplace else you'll need space elevators all over the place anyway.
And I doubt it makes sense to settle on any planet or moon unless it can sustain life without life support, or at least with less life support. Why build anothe
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For an idea to be practical.... it first has to be, well, practical. Which an optical interferometric telescope of that size, isn't.
Among other problems, it would be many orders of magnitude bigger than any such telescope currently in operation. (Currently, the largest such interferometric scope is only a couple of hundred meters across.) The engineering challenges involved in building the observation stations alone are staggering, let alone the interconnections between them.
Re:reason for going to the moon... (Score:4, Insightful)
Who said anything about it being optical?
I was actually envisioning an array of radio telescopes, and smaller optical ones used in concert to create a composite aperature.
We have sufficient data processing technology, and the construction and engineering requirements for the individual nodes of the array are not that different from what is currently in operation.
The difference would be entirely from the location. On the moon, it des not pose an environmental impact on any life forms. It does not run into problems with human economic activities (as pointed out countless times by others, mining on the moon will never be practical), it is far removed from human radio sources on the dark side of the moon, is removed from earth light pollution and atmospheric defraction, and does not need any station keeping equipment.
Freed from all those constraints, and with the potential to be an astronomical array of unprecidented size, it is hard to imagine reasons NOT to do I, if scientific investigation is truly the motivator. (With an aperature that size, the potential to directly image an exoplanetary system becomes plausible, as well as charting the local stellar neighborhood with previously impossible levels of detail.)
If it helps you to imagine what I envision here, I will describe the array for you.
There are 2 concentric circles of discrete radio and optical telescope "nodes" on the dark side of the moon, linked with optical fiber data interconnections. There are 4 additional semicircles that are tangent to the inner circle, and meet at 90 degree intersections with the outer circle. (Forms a diamond shape.) The combined data from these nodes allows the digital reconstruction of what would be observed, as if the entire dark hemisphere of the moon had been completely covered in nodes. (At least for radio wavelenths.)
You would only need a few hundred nodes.
On the light hemisphere of the moon, you construct the communications tower.
I was in no fashion suggesting plastering the entire dark side of the moon with CCDs. That is unfeasible logistically, and unnecessary. The point of having multiple points for interferometry is to permit multiple simultaneous observations of distant objects, and to have a variety of interferometric angles from which to discriminate frequency of emission with.
Eg, the array could track multiple objects, give location, vector, speed, and suggestions on composition for all of them simultaneousy. It could also be used in aggregate to observe a single, very distant object using a statistical approach to resolve signal from noise.
It would be well within our engineering capacity.
It would just cost an unbelievable amount of money.
Unlike an artificial satellite however, it only needs to be made ONCE.
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I presumed optical since you specifically mentioned pictures and the Hubble. If you meant radio, we can and already do 'build' interferometric radio telescopes the size of the Earth - which is much larger than the moon. Going to the moon gains us nothing.
The mind boggles at the level of cluelessness involved in beli
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No, you are being a dick. :D that is an entirely different problem, and is more yours than mine.
Here: there is no reason why the array cannot be both (local) optical, and (collectively) radio in scope.
The "earth sized" interferomtric radio telescopes you mention, (like the square kilometer array) have fixed angles of observation. A large dedicated array on the moon in the configuration I cited would have multiple graduated angles of interferometry, allowing greater precision of measurement. Being on the da
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What benefit is there from sticking the optical telescope on the moon? There isn't any kind of interferometry going on as far as I can tell, so it wouldn't really do anything the hubble couldn't do. Plus, then you don't have lunar dust to deal with (not sure how much of that lands falls - obviously no atmosphere but anytime a meteor hits the moon it would kick some up). Maybe a radio telescope would benefit from shielding from the Earth, but I don't see why you couldn't just stick one in orbit (the refle
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Unfortunately, you are probably right. :(
Still, using the moon as a stable platform for deep space sensors is a much more sensible application than a human lunar colony. (Even just within our solar system, the array would greatly reduce the need for expensive probe missions for general data collection. An effective aperature of that size would let you see things that even the best terrestrial telescopes could never image. We could use it to listen to the magnetosphere of jupiter, for instance, or to track
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More like:
"Hey NASA, we know you have this fancy data aggregation and digital image processing system up on the moon, designed to correlate a huge number of discrete data sources. Well, we have a huge number of spy satellites that we want to have processed. If you want more funding, you'd better let us make use of the goods."
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If you're talking about an interferometric radio telescope, the atmospheric distortion isn't a big deal, an aperture the size of the moon is smaller than arrays already built on the earth, and there's no benefit to having the elements of the interferometer on the moon rather than as free-orbiting satellites. In fact, with the RadioAstron [wikipedia.org] satellite being used in conjunction with earth-based telescopes, we've already got an effective aperture size of 400,000 km.
If you're talking about an interferometric opti
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Why is this so hard for people to grasp?
No, I dont mean trying to interfere two beams of visible light from either side of the moon's circumference. As you point out, this would pose serious problems.
Instead, the optical portion of the array would use large, high resolution CCDs at each node. The data gathered from the CCDs would be processed digitally, and compensation for the viewing angle would be performed digitally. The combined datasets would be statistically filtered to increase the signal to noise.
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L2 is bullshit. Sure, it's easy. No gravity well to deal with. The goal should be boots on Mars.
Please don't misunderstand me and think I'm opposed to this. I'm all for it. But as Kennedy (that filthy Democrat!) said, "We do these things not because they are easy but because they are hard..."
Mars. Boots.
Teleoperating rovers (Score:4, Informative)
There's only a 1.3 second one-way communication delay between here and the Moon, making real-time control from Earth perfectly feasible (unlike Mars which has a 3 to 22 minute delay). The L2 point is even further away from the moon than the Earth is (on average around 4-5 times further) , thus there is an even larger communication delay which would make real-time control far less practical. Teleoperating a rover on the moon is a very contrived reason to place humans at the L2 point.
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Isn't the JWST supposed to park there?
No, James Webb Space Telescope will be at Sun-Earth L2 we're talking about Earth-Moon L2 here.
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The L2 point is even further away from the moon than the Earth is (on average around 4-5 times further) ..
L2 is closer to the Moon that the Earth is to the Moon. Lagrange Points of the Earth-Moon System [gsu.edu]
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Then the Wikipedia link in the story refers to the wrong L2 (earth / sun).
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Screw 'em
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more to the point, there is a volume where the net gravitational field (and orbital forces) nearly balance out. Assuming you are near this place, your station keeping efforts are minimal, but not zero as the location of the 'perfect spot' moves slightly as the moon/earth/sun relationship changes. Multiple vehicles can be in the region with similar energy requirements for station keeping.
Paging Mr Hill and Mr Gibbons (Score:2)
Yeah...how how how how... how how how how ... at that base out at .... Lagrange (2) ......
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They gotta lot of nice girls there.
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I think it would be awesome for man to finally set foot on the moon.
On 20 July 1969, he will.
Location location location (Score:1)
Maybe Someone Should Explain L2? (Score:5, Informative)
Maybe someone should explain L2? LaGrangian points are not exactly common things discussed over coffee, and the importance of the Earth/Moon L2 isn't going to be readily understood by most people.
L2 is referring to the L2 Langrangian point
Quick Primer:
Any time two planets interact with each other there are 5 points where gravity is essentially zero. These can be though of as eddies in a stream. These are known as "Lagrangian Points". They are referred to as L1, L2,...L5. L1 is the point between Earth and the Moon. L2 is the point behind the moon. L3 is the point behind the Earth. L4 and L5 are not in a direct line between the two bodies. They exist at a 60 degree angle off of the first 3.
These Lagrangian points exist between ANY two gravitational bodies. The greater the gravity, the larger the 'hole'. Anything that falls into this 'hole' stays there. This makes it ideal for a satellite or similar. It wouldn't drift away. Just like the eddy in a stream, the external current keeps forcing everything back into the hole.
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"L1 is the point between Earth and the Moon. "
Ok, moon pulls in one direction, Earth in another. Total gravity zero.
"L2 is the point behind the moon."
Both Earth and Moon pull you in the same direction. Total: Not zero. Something is wrong with your explanation.
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"L1 is the point between Earth and the Moon. "
Ok, moon pulls in one direction, Earth in another. Total gravity zero.
"L2 is the point behind the moon."
Both Earth and Moon pull you in the same direction. Total: Not zero. Something is wrong with your explanation.
http://en.wikipedia.org/wiki/Lagrangian_point#L2
Gravity and centrifugal effects balance out at L2.
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Hope the explanations helped. I was just trying to make sure people understood as quickly as possible. I mostly just wanted to get the word "Lagrangian" into the discussion and displayed as quickly as possible. I figure people can "google" Langrangian. It is a bit difficult to google "L2". It reads like gibberish.
So, there were some technical errors. Also, some of the Langrangian points are more stable than others. This was just a "quick primer"
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L1-L3 are not technically stable. However, you can keep in position using very little fuel. Also, they've devised some funky micro-orbits about these points that help, too.
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Only L4 and L5 are stable in the way you suggest. The other ones are not - you need to make corrections to maintain position, though they are small compared to the kind of continuous thrust you'd need to keep a constant relative position elsewhere in the system.
Dark orbit (Score:1)
Is there a "dark orbit" about the moon that stays perpetually in shadow (28 day period), or would that be too close to earth to be stable?
If it could work, that would be a neat place for a deep space station - giant solar radiation shield, all you have to do is bring your own nuke powerplant instead of using solar panels. Still get to see the earth most of the time, too.
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No. Staying purpetually in the moon's shadow would require lunar-centric orbit. The moon's gravity well is very shallow, and dominated by the earth's. Orbital resonances with the earth would make any spacecraft attempting to stay in the moon's shadow have to actively perform continuous course corrections.
By comparison, the L2 lagrange point is a "calm waters" location, where gravitational influences from both the earth and the moon are balanced perfectly. A spacecraft at this location with the correct momen
Neither Moon nor LEO nor L2 (Score:3)
I've just read an excellent book by aerospace engineer Robert Zubrin, called "The Case for Mars", in which he argues in great detail for the possibility of puting humans on Mars in our own generation. His project is called "Mars Direct", and involves basically a Saturn V class launcher, which can take, on a first mission, an habitat which would be used to generate supplies (fuel, oxygen, water etc.) from Mars natural resources, and on a second mission, a crew of four Earthlings. The idea is that when the crew arrives, the factory from the first mission has generated enough fuel, water &c. for the return trip, as well as to power rovers ando other equipment.
His project is very credible, and he estimates a cost of 30 billion USD (which is peanuts when compared to other manned Mars missions projects [vide "90-day report", on the order of 450 billion USD]) for the first launch, with costs amortized over multiple launches.
Mr. Zubrin also argues that going to the Moon is pretty much useless, because it has nearly no natural resources to be explored and exploited, and almost as costly as going to Mars.
If you will, his site is at http://www.marssociety.org/ [marssociety.org] . The book is great reading too, and inspiring as it gives me the hope to see one of my own species walking over the Red Planet.
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Only so long as you're not picky about details - like the difference between a technology that's barely been tested on the lab bench and one that's actually been prototyped and tested and ready for development into a flight article. Zubrin is very fuzzy on the difference, and treats the former as if it were the latter... resulting in some very optimistic budget and schedule assumptions.
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Well, I confess I'm not a conoisseur of these subjects, but the technology he proposes is one we've had (not really "we", but you Americans) since the 60's: Saturn V launchers, habitation modules akin to the Lunar Module AND the ISS etc. Maybe I'm too easily influenced, maybe I'm too hopeful, but I'm inclined to believe what he said.
As for the amortized costs, what you said is true if we consider "one mission" two, four, six or another even number of lauches as a whole (to put a crew on Mars, Zubrin propose
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Well, other the fact that ISS type systems would require considerable modification... (the thermal environment is radically different, as is the radiation and micro meteor envi
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At the other extreme, I read a short story, "Return to the Golden Age", where orbits of Earth are crammed and many people have private space ships, but nobody still went back to the moon, so somebody does.
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I loved his "First Landing", even though the end isn't as appealing as it could be. The novel is about a "what if" his Mars Direct plan were done in the present.
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While Robert Zurbin is an interesting person and I like some of the arguments that he makes in that "Case for Mars", I flat out disagree with his notion we should abandon the Moon as a source of resources or even for scientific exploration. It is an interesting place to hang out for a variety of reasons all to itself, and offers some interesting and even unique attributes that make it useful. For myself, I think development and even settlement of the Moon should be happening at the same time as similar de
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I keep seeing aburd rhetoric like this. At this point I am not sure if this can be ascribed to shameless trolling, or to poes's law gone terribly wrong.
Regardless, the concentration of melanin in human skin does not have a demonstrable relationship with mental ability. If it did, there would be a profound trend in medical literature, as people would become dumber after summer sun exposures. This does not occur. Therefore, the color of the skin is meaningless for the ascribed metric.
What you are really tryin
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Regardless, the concentration of melanin in human skin does not have a demonstrable relationship with mental ability. If it did, there would be a profound trend in medical literature, as people would become dumber after summer sun exposures. This does not occur. Therefore, the color of the skin is meaningless for the ascribed metric.
Excuse me, have you ever seen Jersey Shore? Not to say you're wrong, I just had to throw that out there.