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NASA Mulling Earth-Moon L2 Point for Mars Staging Station

Unknown Lamer posted about 2 years ago | from the my-religion's-in-space dept.

Mars 186

jamstar7 writes "From the article: 'NASA is reportedly mulling the construction of a floating Moon base that would serve as a launching site for manned missions to Mars and other destinations more distant than any humans have traveled to so far. The Orlando Sentinel reported over the weekend that the proposed outpost, called a "gateway spacecraft," would support "a small astronaut crew and function as a staging area for future missions to the moon and Mars."' This is actually a good idea, using the Moon as a staging base for exploring the cosmos. Once we build manufacturing capability there, why not build spacecraft there? We can build bigger, more spacious craft so as to not lock up future astronauts in a closet for months or years at a time." Moon base isn't quite accurate: it would be a space station at the Earth-Moon L2 Lagrange point about 60000 km from the surface of the dark side of the moon.

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test (-1)

Anonymous Coward | about 2 years ago | (#41461695)

testdff

Why not build spacecraft there? (1)

TheMathemagician (2515102) | about 2 years ago | (#41461705)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

Re:Why not build spacecraft there? (1)

Anonymous Coward | about 2 years ago | (#41461727)

Yes we do, we just don't want to...

Anyway NASA can make a kickstarter project to raise money, seen silly projects getting 1M from vapor.

Re:Why not build spacecraft there? (1)

Anonymous Coward | about 2 years ago | (#41461829)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

history suggests the spinoffs we'd get from trying would more than pay for itself.

Re:Why not build spacecraft there? (1)

Cold hard reality (1536175) | about 2 years ago | (#41462123)

So engage in basic research. Why do it indirectly?

To provide a long term goal (4, Interesting)

Anonymous Coward | about 2 years ago | (#41462167)

A lot of the "basic research" comes from applied research aimed at a specific goal, the spin-offs from that basic research is what provides the expanded benefit.

Hypothetical goal: L2 staging base
Hypothetical applied research: supporting medical facilities there.
Hypothetical spinoffs: remote surgery, 0 G surgery, remote sensing, microrobotic surgery... and reduced medical costs on earth.

Re:To provide a long term goal (3, Insightful)

ByOhTek (1181381) | about 2 years ago | (#41462547)

Why don't we add lunar resource acquisition as spinoff applied research?

With a smaller gravity well than Earth - it could be the future of space based colonization.

This would probably then add to research that could go towards colonizing extraterrestrial bodies.

Re:To provide a long term goal (1)

Cold hard reality (1536175) | about 2 years ago | (#41463343)

What lunar resource? Rocks?

Have you considered the huge amount of infrastructure needed to extract resources? Now multiple that by a few thousand dollars per kilogram. Do the math.

Re:To provide a long term goal (1)

Cold hard reality (1536175) | about 2 years ago | (#41463315)

Just invest in medical research directly. Like remote (or just local robotic) surgery. Cut out the middleman.

Romney wants Florida (1)

Anonymous Coward | about 2 years ago | (#41462067)

The only reason space has been in the news as of late, is that Romney wants to win Florida. This is the same Romney that famously said he would fire an employee that would spent hundreds of billions on a moon base (size unspecified) in a 2012 Republican Primary debate. The only reason any manned space program exists is because of senators in Florida, Texas and Alabama want to keep their pork. Back in the early 2000s, NASA wanted to research alternate launch systems and operations. That was cancelled of course, and Mike Griffin lead the way in building a big, expensive rocket.

Windows that open in jet airplanes (1)

Anonymous Coward | about 2 years ago | (#41462119)

Romney wants windows that open in jet airplanes too. He cannot have everything he wants.

“When you have a fire in an aircraft, there’s no place to go, exactly, there’s no — and you can’t find any oxygen from outside the aircraft to get in the aircraft, because the windows don’t open. I don’t know why they don’t do that. It’s a real problem. So it’s very dangerous.

Source: http://www.latimes.com/news/politics/la-pn-romney-beverly-hills-fundraiser-20120922,0,2317962.story [latimes.com]

Yes, it's off topic, but I'm not the one bringing in the politics.

Re:Windows that open in jet airplanes (1)

mbone (558574) | about 2 years ago | (#41463729)

I am not pro-Romney, but it is pretty clear that that was a joke (and, for Romney, a pretty good one).

Re:Why not build spacecraft there? (5, Informative)

lessthan (977374) | about 2 years ago | (#41462585)

Not having a trillion dollars really hasn't stopped our government from spending like they do, so why not?

Re:Why not build spacecraft there? (1)

slashmydots (2189826) | about 2 years ago | (#41462911)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

Another good reason is because we don't have any metal or fuel or supplies or people or vendors or communication infrastructure or USPS addressing locations or anything other than moon dust and nothingness on the moon.

Re:Why not build spacecraft there? (4, Insightful)

jamstar7 (694492) | about 2 years ago | (#41462997)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

Another good reason is because we don't have any metal or fuel or supplies or people or vendors or communication infrastructure or USPS addressing locations or anything other than moon dust and nothingness on the moon.

Yet.

How many times must it be pointed out that back before Columbus sailed to the Americas, there were no Starbucks or Dunkin Donuts or Apple stores in the area now known as the United States? Wasn't a lot of anything except a lot of forest.

Re:Why not build spacecraft there? (3, Insightful)

Yobgod Ababua (68687) | about 2 years ago | (#41463907)

"Wasn't a lot of anything except a lot of forest."

So only...
Old growth trees (extremenly valuable at the time for shipbuilding).
Vast tracts of untilled arable land.
"Easily displaced" indiginents.

Not to mention the coal and oil deposits discovered later.

We know a lot more about what's on the moon than Columbus (or the Spaniards) did about North America, but what we know is that it's not all that.
The moon, sadly, is kind of crappy resource-wise. It is, on the other hand, really handy for causing tides, which helped a lot of life proliferate down here, so go moon! (but don't necessarily go TO the moon)

Re:Why not build spacecraft there? (2)

flappinbooger (574405) | about 2 years ago | (#41462961)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

Well we DID have a spare trillion, apparently, but it went to da bankers via stimulus...

Re:Why not build spacecraft there? (1)

Joce640k (829181) | about 2 years ago | (#41463259)

Yep. How can it possibly be cheaper/easier to build spacecraft out in space. You still have to send materials up there, surely it's easier to send them into earth orbit than the other side of the moon.

Re:Why not build spacecraft there? (5, Insightful)

SecurityGuy (217807) | about 2 years ago | (#41463389)

1) Money isn't actually used up when we build things. The money goes into the hands of the people who build them, the people who create the materials in them, etc. None of the money will actually leave the planet.

2) I'd rather spend a trillion dollars doing this than spend a trillion dollars fighting wars we don't need to fight.

Re:Why not build spacecraft there? (1)

Thud457 (234763) | about 2 years ago | (#41463577)

Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.

really?! [wikipedia.org]

Re:Why not build spacecraft there? (1)

Grizzley9 (1407005) | about 2 years ago | (#41463943)

This. I don't think most realize just how complex spacecraft are and the materials needed let alone manufacturing in micro-g environment.

Dark side, really? (5, Insightful)

pmontra (738736) | about 2 years ago | (#41461713)

Dark side as in "never receives the light of the Sun"? The Pink Floyd are still casting a dark shadow on astronomy beliefs ;-)

Re:Dark side, really? (1)

alex67500 (1609333) | about 2 years ago | (#41462041)

Maybe dark as in the other side, so no communication with Earth because the Moon is in the way.

"Houston, we're going dark" (Appollo 13, almost ;-)

Re:Dark side, really? (1)

benjfowler (239527) | about 2 years ago | (#41462361)

Until somebody gets around to launching a set of lunar comsats similar to the TDRS network around Earth.

Re:Dark side, really? (1)

trout007 (975317) | about 2 years ago | (#41462063)

There are a few dark places on the moon as in never receives the light of the Sun. They are craters at the North and South Pole.

Re:Dark side, really? (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41462187)

To me, it's the part where there is night on the Moon at the moment. Therefore, its distance to the Earth-Moon system's L2 point isn't fixed, but the "about 60000 km" statement which seems to cover distances in the range of 55000 to 65000 kilometers (the way they taught us to deal with uncertainties at my uni) still applies.

Re:Dark side, really? (1)

Hillgiant (916436) | about 2 years ago | (#41462393)

Not everyone is talking about the visible spectrum you insensitive clod.

Irrespective of where the sunshine is falling, not being able to maintain direct radio contact seems like a considerable detriment to me. I.e. radio-dark.

Re:Dark side, really? (1)

marsu_k (701360) | about 2 years ago | (#41462845)

Actually, if you listen to the end of the album very closely (you might need to turn up the volume), there's a person saying "There is no dark side of the Moon really... matter of fact it's all dark."

Re:Dark side, really? (0)

Anonymous Coward | about 2 years ago | (#41463217)

No, dark side as in "never receives the light of the Earth".

Dark side of the moon... (5, Informative)

Ecuador (740021) | about 2 years ago | (#41461745)

For something to be X miles above the DARK side of the moon, it would have to be orbiting the moon. You want to say FAR side of the moon, and you would probably not get it wrong if you either paid a little attention to your science classes in school or gazed at the moon enough times to think about the lunar phase cycle.
But, no, you should not be editing something like slashdot causing the readers to pull their hair.

Re:Dark side of the moon... (2, Interesting)

multi io (640409) | about 2 years ago | (#41461839)

The part of the dark side that you would see from L2 would be REALLY dark though, because it would not only NOT receive light from the sun, but it would also NOT receive light from the earth. Effectively, it would only be lit by starlight, which is almost nothing. That's in contrast to the part of the dark side that you can see from earth, which is never totally dark, because it receives earthlight.

Re:Dark side of the moon... (0)

Anonymous Coward | about 2 years ago | (#41461901)

The moon rotates on its axis every 28 days, give or take, which just happens to be its orbital period around Earth. The far side of the moon gets full sunlight while our side is in the new moon phase, etc., etc..

Re:Dark side of the moon... (2)

multi io (640409) | about 2 years ago | (#41461957)

I know. By "dark side of the moon" I mean the part of the lunar surface that doesn't receive direct sunlight at a particular moment in time. I didn't mean to say that that's always the same geographical region of the surface.

Re:Dark side of the moon... (2)

camperdave (969942) | about 2 years ago | (#41463055)

That would be called the Night side. Really people. We have proper names for these phenomena. Let's start using them.

Re:Dark side of the moon... (1)

pmontra (738736) | about 2 years ago | (#41461923)

Let's suppose that this is right... When the moon is new it is between the sun and earth. That's why we see it as dark and it's there that sun eclypses happen, when it is exactly on the light of sight between us and the sun. The next new moon will be on October 10. At that time one side of the moon will get light from sun and the other one will get light reflected by earth. On which side of the moon will be this L2 point at that time?

The only way out is that L2 will be on the night side of earth but I understood that this is the L2 point of the moon-earth system, not earth-sun.

Re:Dark side of the moon... (5, Informative)

Anonymous Coward | about 2 years ago | (#41461945)

Sorry, your explanation has confused me somewhat.

I've always known the dark side of the moon to mean the side of the moon that never faces earth, aka the far side of hte moon.

The dark referes to the fact this side of the moon never recieves any signals from earth NOT that it never recieves any sunlight (which it does during every new moon).

In case you wish accuse me of not paying attention during science class:

http://en.wikipedia.org/wiki/Far_side_of_the_Moon:

"The far side of the Moon, sometimes called the "dark side of the Moon" in the sense that it is in a radio blackout in respect to transmitters on Earth"

IIRC placing an object so that it's constatly observing the dark (as in no sunlight) side of the moon is refered to as in the shadow of the moon, but I'm not 100% on that.

Re:Dark side of the moon... (2)

Ecuador (740021) | about 2 years ago | (#41462533)

The definition of "dark side = the side that does not receive signals directly from earth" sounds to me as simply tailored to give a plausible explanation to the incorrect usage of the term (thank god for radio signals, back in my day we didn't have such fancy ways of explaining why we were using wrong terminology).
Think about this: if someone tells you Olympus Mons is right now on the dark side of Mars, would you assume it is in the hemisphere farthest from the earth where there is no direct radio contact, or in the hemisphere farthest from the sun where it is, well, you know, dark.
I would be interested to know who first thought of giving the explanation why dark "dark side" can in fact mean "far side", because I suspect the (incorrect) usage of the term "dark side" might be older than radio signals. Of course the wikipedia article is useless, it cites "The Fox News" and "Time magazine" as the sources of the term "dark side = far side".
Also, you seem to be having a problem finding a name for the sun-don't-shine-side of the moon, and that is exactly because you are trying to redefine "the dark side" which is the simplest term. In any case I'll help you with that. It is also called "nightside" (and try looking it up in a dictionary, yep, defined as "dark side").

Re:Dark side of the moon... (5, Interesting)

Megane (129182) | about 2 years ago | (#41462021)

http://en.wikipedia.org/wiki/Lagrangian_point [wikipedia.org]

lrn2orbitalmechanics, it would be orbiting the earth along with the moon.

Not only is it relatively stable (though a halo or Lissajous is usually used), but the relative sizes are such that the moon does not fully eclipse the earth, so continuous communication is available.

It's a lot more sensible than a lunar ground base. Not only isn't there a gravity well, but the Lagrange points are the easiest places from which to leave earth orbit with minimum energy expenditure. If you have a fuel stockpile there, you can top off the tanks and all that fuel goes to the trip, not climbing out of the gravity well.

Re:Dark side of the moon... (1)

AliasMarlowe (1042386) | about 2 years ago | (#41462157)

Not only is it relatively stable (though a halo or Lissajous is usually used), but the relative sizes are such that the moon does not fully eclipse the earth, so continuous communication is available.

A minor correction: orbits which are stable with respect to minor perturbation are possible at the L4 and L4 points. Some powered correction is needed for any orbit at L2 and L3, since they are only stable for the 3-body case [wikimedia.org] , not for the real n-body Solar System.

Also, at the Earth-Moon L2 point, the Earth is fully eclipsed. The Earth's umbral cone extends just over 100000km past the Moon at their average separation of 384000km [wikimedia.org] , but the umbral cone for the Earth is quite thin, and has a diameter of less than 1500km at the L2 point. An orbit which goes occasionally outside the umbra may be possible, but it might involve a fair amount of fuel burn.

Re:Dark side of the moon... (1)

lobotomir (882610) | about 2 years ago | (#41462515)

The James Web Space Telescope will also reside in the Earth-Moon L2 point, and AFAIK it will transmit data directly to Earth, so communication from/to L2 should not be an issue.

Re:Dark side of the moon... (4, Informative)

Tim the Gecko (745081) | about 2 years ago | (#41462697)

The James Web Space Telescope will also reside in the Earth-Moon L2 point, and AFAIK it will transmit data directly to Earth, so communication from/to L2 should not be an issue.

No, the James Webb Space Telescope [wikipedia.org] will be at the Earth-Sun L2 point.

Re:Dark side of the moon... (1)

mbone (558574) | about 2 years ago | (#41463813)

L1, L2 and L3 are not stable even in the modified 3-body problem (i.e., where body at L1, L2 or L3 has no mass).

And, there are definitely Lissajous (Halo) orbits of L2 that are always in view of the Earth.

Re:Dark side of the moon... (0)

Anonymous Coward | about 2 years ago | (#41462205)

If you have a fuel stockpile there, you can top off the tanks and all that fuel goes to the trip, not climbing out of the gravity well.

Well, it still has to get there somehow, and climbing out of the gravity well is the only way we know about. Granted, you can use multiple smaller launches to stockpile the fuel there, and you avoid risk of a colossal failure at single point in time, but you'll end up using up more energy and more hardware in total.

However, if we could establish a mining operation that could somehow obtain fuel from some non-deep place around us, and bring it down to our L2 depot, then it would be most beneficial!

Re:Dark side of the moon... (2)

WGFCrafty (1062506) | about 2 years ago | (#41462031)

There is no dark side of the moon, of a matter of fact, it's all dark.

Good for a lot of reasons... (5, Interesting)

Genda (560240) | about 2 years ago | (#41461783)

By the way, the L2 point is not on the dark side of the moon (the dark side of the moon travels around the moon every 28 days), it is on the FAR SIDE of the moon, that is the side facing away from earth.

My question is why L2 and not L1? L2 is going to be exposed to more meteoric traffic, it will have a hard time communicating through the moon to the earth (yeah you can put a comm satellites at L4 or L5 but that's complicating things and adding cost and new failure modes.) That and L1 is closer and easier to get to from Earth and easier to get things to from the moon with the gravitational assist of Earth.

There are plenty of interesting designs, but such a resource would need to be built of lunar material. Because you'd need a structure with walls thick enough to protect from solar storms, cosmic rays and all kinds of meteoric debris hitting the structure. You would probably want to have hydroponics plants on board for food, oxygen, and synthetic meat from Soybeans... or even better synthetic meat from a 3D printer, endless Filet Mignon, sushi grade Yellowtail and Salmon, and Turkey White and Dark meat as long as you have cell cultures and your meat printer. By the way, you could dissolve vital minerals in water and then use that water to build radiation proof walls. About 3 feet ft. would get the job done nicely, 6 ft would be spectacular. You'd want to harvest a reasonable sized asteroid with plenty of water or a number of smaller asteroids and use it/them to build your base. You'd want to use a swarm of assembly bots to build things with only a small human presence, most remote from the ground. Robots that could self replicate from materials in the asteroids would be perfect.

Re:Good for a lot of reasons... (0)

FTWinston (1332785) | about 2 years ago | (#41461819)

Why not just build the base on Earth, and beam it up, when you're finished designing your Von Neumann machines?

Re:Good for a lot of reasons... (5, Interesting)

art6217 (757847) | about 2 years ago | (#41461921)

A trip to L2 is said to take longer but be cheaper per kg than that to L1... http://www.thespacereview.com/article/1808/1 [thespacereview.com]

Why not LEO, and use the ISS? (4, Interesting)

captainpanic (1173915) | about 2 years ago | (#41462163)

Why not put it in LEO (low earth orbit)? It's a hell of a lot easier to send supplies and astronauts. We have decades of experience with that.
Also, why not use the ISS? It has all you need, I think: astronaut habitat, power, docking ports. Add a few modules, and you're done.

All this talk about either the moon or L1, L2... unless there is a source of fuel (i.e. water, as well as a source of power like sunlight or nuclear), it's utterly pointless to drop yourself into another gravity well, not matter how tiny, if you're gonna have to carry all the fuel there yourself from earth. If the fuel comes from earth, your space station is nothing but an assembly point, and that might just as well be in low earth orbit.

The only reasonable alternative is one of those craters on the moon where they have found some water... but only if a station there can get sufficient power to convert that water to hydrogen and oxygen at conditions (temperature, pressure) that are necessary to be put into a large rocket.

Re:Why not LEO, and use the ISS? (4, Interesting)

hackertourist (2202674) | about 2 years ago | (#41462463)

If I'm not mistaken, ISS is in the wrong orbital plane for planetary missions, so you'd waste a lot of fuel.

Re:Why not LEO, and use the ISS? (2)

captainpanic (1173915) | about 2 years ago | (#41462527)

Ok, I didn't know that (thanks). Why not put another station in low earth orbit, in the right orbital plane?

I still don't see the point of going all the way to L2 if we need to carry all the fuel there ourselves from earth anyway.

Re:Why not LEO, and use the ISS? (0)

Anonymous Coward | about 2 years ago | (#41462669)

I don't know how big of a deal the vertical vector components matter, for the proceding ISS orbit. I suspect it might add maybe a 12%-25% more fuel needed.

That said, there is no reason we can't move the ISS to a better orbit. It's a lot better than dumping it into the ocean in a few years, as is the current plan, I believe.

Re:Why not LEO, and use the ISS? (2)

ceoyoyo (59147) | about 2 years ago | (#41463073)

It takes less fuel (a lot less) to go somewhere from L2 than it does from low orbit. Yes, you have to boost all your assembly materials up anyway, but your actual interplanetary spacecraft can be that much smaller because it doesn't have to carry all the fuel to get out of low orbit in the first place. You don't need to carry as many empty fuel tanks all the way to Mars and back.

Re:Why not LEO, and use the ISS? (1)

captainpanic (1173915) | about 2 years ago | (#41463425)

You can dump an empty tank as easily as any other rocket does. Disconnect it. All rockets have stages. They all dump their empty tanks. Tanks can either have their own engine, like the booster rockets, or no engine, like the big fuel tank of the Space shuttle. Still, all get discarded without a problem.

I'm sorry if I am attacking you a little hard, but your argument makes no sense. You have to regard every mission from the place where stuff is launched (which is Earth, also if your intermediate location is L2).

If all the fuel comes from earth, you save nothing by going to L2 first. The only reason to assemble your Mars craft in space is that you can use multiple launch vehicles to get a larger total mass into space. But the logical assembly place is LEO, or some other orbit around Earth (geosynchronous if you like it higher up), not some far away L2 which has no direct contact with earth because it's blocked by the moon.

And if your craft isn't big enough yet, you just add another stage (either just another fuel tank, or a rocket) to your Mars rocket to get out of LEO.

Re:Why not LEO, and use the ISS? (1)

ceoyoyo (59147) | about 2 years ago | (#41463829)

Stages introduce complexity which means weight and more things to go wrong. Also, you have to get back to where you came from. It requires extra fuel to drop back into a low Earth orbit, fuel that you have to drag all the way to Mars and back. Low Earth orbit also requires constant boosting for your assembly facilities and spacecraft (it costs almost a quarter of a billion dollars annually to boost the ISS). There are probably also advantages to slingshot maneuvers around the Earth and moon from L2. And you don't need to dodge space junk and other satellites. You can also probably arrange for constant sunlight, meaning constant power.

Another advantage is that you can boost equipment up from LEO using high specific impulse engines, like ion drives (takes a while) and people using chemical rockets (fast). Your Mars ship might be able to use only high specific impulse engines but the trip isn't lengthened by the need to climb out of Earth's gravity well.

You're making a big deal out of communications. We're very good at communication satellites. If the construction facility was put into an appropriate orbit at L2 it's even possible you wouldn't need a relay.

There ARE advantages to assembling things at a Langrange point. I don't know whether those advantages outweigh the disadvantages or whether a Langrange point is better than another high orbit, but it's not a completely stupid idea as you seem to think.

L2 Because of it's purpose (2)

brunes69 (86786) | about 2 years ago | (#41461933)

I assume it is L2 specifically because it is a mission staging area. Launches to other planets will be easier and use less fuel if done from L2 because they will not have to navigate around the moon, and because they will be that much closer to the target.

Re:Good for a lot of reasons... (0)

Anonymous Coward | about 2 years ago | (#41461935)

Why L2?

Because it is that much further out of the Earth's gravity well, so less fuel needs to be carried and burnt getting up and away from Earth.

Re:Good for a lot of reasons... (5, Informative)

Framboise (521772) | about 2 years ago | (#41461947)

>My question is why L2 and not L1?

Indeed, I have no clear idea, because once an object is located at one of the five Lagrangian points L1-5, very little energy is required to go to any other one.
L1 needs however the least delta-v to be reached from Earth or Moon, and direct radio communications are possible with L1 and L3, contrary to L2 which is hidden by the Moon from Earth. L3, on the side opposed to the Moon would require still a bit more delta-v than L2. L1-3 are dynamically unstable, so a station there would need periodic corrections.

L4 and L5 are more stable than L1 or L2 but require still a bit more delta-v wrt L1-3.

To reach Mars, or any escape from the Earth-Moon system L1_5 are almost equivalent if enough time is available, but L4-5 provide more orbit choice, so more possibilities to choose quick routes.

Note that the station would not need to be located precisely at one of the L1-5 points, but could be on so called halo orbits circling around such a point.

Re:Good for a lot of reasons... (1)

BadgerRush (2648589) | about 2 years ago | (#41462825)

Just a quick fact: Under current plans, a spaceship wouldn't be parked at the L2 point, it would orbit it. So, with a wide enough orbit, an L2 bound ship would be able to have direct line of sight to earth.

Re:Good for a lot of reasons... (0)

Anonymous Coward | about 2 years ago | (#41461991)

I've correct someone else above but in case a lowly AC gets dismissed out of hand:

http://en.wikipedia.org/wiki/Far_side_of_the_Moon:

"The far side of the Moon, sometimes called the "dark side of the Moon" in the sense that it is in a radio blackout in respect to transmitters on Earth"

so, in this case, dark doesn't mean what you think it does.

Re:Good for a lot of reasons... (0)

Anonymous Coward | about 2 years ago | (#41462239)

There are two good places to put a space outpost: Earth-Moon L1 and Earth-Sun L2. I think perhaps people are confused about the difference. For cislunar space, L1 is best because it's much closer to Earth which makes the fuel costs are a lot lower. Plus delta V to the lunar surface is relatively low from there so you could have a reusable moon lander that "parks" at the outpost. For interplanetary travel, Earth-Sun L2 is awesome because you can practically shove a spacecraft to another planet from there since Earth's gravitational influence is so small. Connecting the two, there are some very low delta V (around 600 m/s) orbit transfers between the two, so once you get something to EML-1, you can send it to SEL-2 for very low cost; of course such an efficient route would take much longer than the more traditional hohmann transfer, so it would be unmanned vehicles only since nobody wants to spend 6 months traveling 3 million miles when the direct approach can do it in about a month.

Re:Good for a lot of reasons... (2)

mbone (558574) | about 2 years ago | (#41463661)

The difference in delta-V to L1 and L2 is (for the Moon) pretty small. In fact, if you are willing to take your time, you can get to either with basically no fuel beyond a geostationary transfer orbit injection, using WSB [utexas.edu] trajectories. (This will take months, so it is not so good for manned voyages, but would save a lot on supply logistics costs, up to doubling the payload delivered per launch.)

By the way, getting a space station from L1 to L2 (or back) is also not energetically hard. The NASA plans on this envision putting a habitat at EML1 and then later move it to EML2, and maybe back after a period. (The station would not be AT EML2, but in a Lissajous orbit about it big enough so that it was always in view of Earth.)

Re:Good for a lot of reasons... (0)

Anonymous Coward | about 2 years ago | (#41462839)

Well, actually the points are numbered sequentially, L1 is the easiest, and L4 and L5 are equivalently difficult.

But that is not the only factor, With electric propulsion, you probably want the furthest out, while with chemical propulsion
(High Thrust) you want to swing low over the earth while you are firing your engines.

Of course there are plane change questions (where is mars,earth, moon etc) and yearly differences (mars is a little eccentric) so it is all a little iffy anyway.

-G.

Re:Good for a lot of reasons... (1)

mbone (558574) | about 2 years ago | (#41463715)

My question is why L2 and not L1? L2 is going to be exposed to more meteoric traffic, it will have a hard time communicating through the moon to the earth (yeah you can put a comm satellites at L4 or L5 but that's complicating things and adding cost and new failure modes.)

The sensible plan and undoubted intention would be to put the station not at EML2, but in a Lissajous (or Halo) orbit about it big enough so that it was always in view of Earth. Such orbits exist and are energetically easy to get to, although a little station-keeping may be required (as it would be for the L2 point as well).

test (-1)

Anonymous Coward | about 2 years ago | (#41461845)

Test

save trillions (1)

GarretSidzaka (1417217) | about 2 years ago | (#41461849)

Why not save trillions and just mount VASIMIR onto the International space station! Would get that thing out of useless low orbit and int the lagrange where she could really get sprawling in size

Re:save trillions (1)

jkflying (2190798) | about 2 years ago | (#41461969)

ISS isn't sufficiently shielded to be outside of LEO

Re:save trillions (1)

BadgerRush (2648589) | about 2 years ago | (#41462971)

What if, instead of letting it re-entry in a few years, they pushed it beyond LEO just to be used as a base for a new one. Even without the proper shielding most of the hardware would be useful, they just need need some new habitat modules and some replacement for the more radiation sensitive equipment.

Re:save trillions (2)

Megane (129182) | about 2 years ago | (#41462015)

Because LEO is still inside the gravity well. Not that the ISS doesn't need VASIMR for station keeping, but it's not designed to go somewhere else. I'm sure that it would probably take some structural damage from the kind of thrust you need to apply to get up out of LEO, and then it has to go through the Van Allen radiation belts too. You just don't move a fully assmembled multi-segmented space station around like it was an aircraft carrier. Over that kind of scale it should be pretty flimsy.

Besides, there's going to be barely enough power available to use VASIMR just for station keeping. I think it needs to charge for like 20 minutes to get a 5 minute burn or something like that. (too lazy to look up the details)

Re:save trillions (1)

BadgerRush (2648589) | about 2 years ago | (#41462927)

I don't think the ISS would take structural damage from a VASIMR propulsion for two reasons:
  1. The thrust from a VASIMR would be very weak, it is more of a slow and steady kind of engine.
  2. It was designed to be “pushed around”, I believe (I may be wrong here) they even used the main thrusters of the space shuttle to adjust its orbit sometimes.

Now, regarding the radiation belts you may have a point. They could evacuate the station before passing troug them, but then, the radiation there would probably fry some/most of the station's electronics.

Re:save trillions (0)

Anonymous Coward | about 2 years ago | (#41463057)

Um, first off, the shuttle used to push it up, and that wasn't always smooth. Second, you apparently know nothing about zero gravity and orbital mechanics. The ISS isn't floating in some ocean of air -- it's racing around the Earth, with the outward centrifugal force of its orbit balancing and counteracting the inward pull of Earth's gravity. Air resistance aside, there is NO minimum acceleration required to overcome gravity. No 1.2g, no 2g, nothing. Gravity has ALREADY been overcome. Can you understand that? That's the whole point of an orbit: it is a stable condition that does not require any additional energy or momentum to continually hover above the Earth.
In theory, if there was no air resistance, the ISS could simply point their cooling radiators at the Earth, and the miniscule momentum from the infrared photons would be enough to eventually send it to escape.

Sheesh. I hate it when idiots try to put down good ideas. Also, who are the idiots who modded this guy up?

Re:save trillions (0)

Anonymous Coward | about 2 years ago | (#41462715)

Because ISS is a piece of crap. Really. It wouldn't survive the journey, never mind being out there getting bombarded with crap.

The entire construction of it saddens me. It could have been so much more.

Sounds like a Death star! (0)

Anonymous Coward | about 2 years ago | (#41461889)

I didnt know Darth Vader had been employed by NASA.

Re:Sounds like a Death star! (1)

nozzo (851371) | about 2 years ago | (#41462159)

That's no moon!

minus_ 1, TrOll) (-1)

Anonymous Coward | about 2 years ago | (#41461987)

with the work, or fueling internal Pallid bodIes and fear the reaper gone RomeO and out how to make the things in

Deeply impressed... (0)

Anonymous Coward | about 2 years ago | (#41462005)

... by the number of geeks who know that there is no dark side on the Moon and proud of it.

But what does this have to do with Australia? (0)

Anonymous Coward | about 2 years ago | (#41462013)

I come here to see stories about Australia! Don't the /. editors understand just how much my needy and fragile psyche depends upon believing that Americans are eagerly reading about my country?

Dark ~ Unknown (0)

Anonymous Coward | about 2 years ago | (#41462039)

One of the meanings of :dark: not in common usage but nonetheless still used is "unknown".

Re:Good for a lot of reasons. (0)

Anonymous Coward | about 2 years ago | (#41462147)

And then we begin to build Colonies. C'monnnn Gundams.

Why not modular? (1)

Lumpy (12016) | about 2 years ago | (#41462181)

Why cant we simply build it modular? Base the Mars mission craft on the ISS. we can launch the modules over a 3 year time span, use it as a second space station for that time while we build it and then when we finally launch up the main engines, hook em up to the hitch and let it rip.

Re:Why not modular? (1)

jamstar7 (694492) | about 2 years ago | (#41463099)

Because the ISS orbit is shit. They put it there so the Russians can land Soyuz capsules in Russia (or a semifriendly 'stan). It's way too inclined to be useful for much of anything else.

Waste of money, go Mars Direct (5, Informative)

kbonin (58917) | about 2 years ago | (#41462265)

Anyone who thinks this is a good idea to get to Mars needs to read Zubrin's "The Case for Mars" or read up on the "Mars Direct" approach. All this talk about moon bases or staging in orbit or at an Lagrangian point originates in NASA designing the Mars mission via lots of committees, in which various teams and [sub]contractors got to insert dependency on their pet projects. Mars Direct presents a very well thought out and fully vetted approach, nothing but politics at this point is standing in the way - if NASA as an agency was still primarily interested in space exploration instead of pork disbursement and fiefdom preservation, and Congress had to provide slightly longer term budget commitments with less constraints and strings atached, we'd already have a permanent presence on Mars.

Re:Waste of money, go Mars Direct (0)

Anonymous Coward | about 2 years ago | (#41463477)

Mars Direct presents a well thought out plan that depends on a lot of aggressive, poorly vetted, assumptions to make its mass ratios work out. But hey it sounds good in a book form.

Many of its features have been adopted in part in more recent NASA Mars plans...those these also often include some other assumptions. Note that the most recent reference architecture does call for a number of significant technology advancements to make its mass ratios work out. If we get conservative and remove these advances the missions balloon even larger (and is well studied in the DRA appendices and in several published alternate studies).

    However, L2 stations are being proposed because they provide staging for missions that are much nearer term than any potential Mars mission--I know that people like to think of this as a "Mars mission base", but realistically we are not doing that anytime soon.

Save L2 for astronomy! (0)

Anonymous Coward | about 2 years ago | (#41462457)

L2 is the ideal place in our planetary system for astronomical observatory. Busy port and shipyard should be placed elsewhere.

No they won't (1)

Hentes (2461350) | about 2 years ago | (#41462493)

With the elections coming all kinds of crazy ideas are floating around. NASA simply doesn't have the resources for a huge project such as this. Also, I don't really see the advantages over LEO, even if they build the station keeping it supplied would be a constant challenge.

Pretty sure I said this the other day (1)

kiriath (2670145) | about 2 years ago | (#41462499)

In the Romney/Ryan space plan post... although I suggested an actual base ON the moon, but something is better than nothing.

For Shame (0)

Anonymous Coward | about 2 years ago | (#41462531)

46 posts and not one ZZ Top joke? For shame, for shame. I come here to be amused, as well as get some learnin...

That's no moon... (1)

wonkey_monkey (2592601) | about 2 years ago | (#41462573)

...that's a gateway spacecraft!

Psychological effects (1)

necro81 (917438) | about 2 years ago | (#41462729)

There's been a lot of research into how humans deal with the psychological effects of long-duration spaceflight. The months-long cruise phase of a Mars mission, when neither Earth nor Mars is visible, and all you are doing is waiting for the light-minutes to pass, is supposed to be particularly difficult. Can we speculate on the effects of building spacecraft out at L2, where the Earth will be perpetually obscured by the Moon? You are close enough for near real-time communications, but won't have much to see out the window. For a week or two out of every month, there will be near total darkness. Other times there will be the unfamiliar face of the Moon's far side. It seems like a rather difficult setting to be in.

L2 - How does it work? (1)

bluesky74656 (625291) | about 2 years ago | (#41462739)

I am not a physics major, but maybe one can help me out. I'm having a hard time picturing how the L2 point exists, or the L3 for that matter. It seems to me that at those two points the Earth's gravity and the moon's are pulling in the same direction. Where is the force working against the moon's gravity for the L2 point or the Earth's for the L3 coming from?

Re:L2 - How does it work? (1)

Barryke (772876) | about 2 years ago | (#41462965)

IANAE (i am not an expert) but.. yes Earth+Moon gravity are pulling in the same direction. And this combined vector is canceling the centrifugal force of orbiting earth+moon.

I guess that L2 is where the sling (centrifugal force) and gravity of earth+moon combined cancel eachother.
L3 is the same, but sideways. It rotates around the earth in step with the moon.

Re:L2 - How does it work? (1)

Framboise (521772) | about 2 years ago | (#41463037)

The Earth-Moon system is approximately stationnary in a particular rotating frame, not an inertial frame. In such a non-inertial frame the centrifugal and Coriolis forces must be added to gravitational force. At the Lagrange stationnary points velocity is zero so the Coriolis force vanishes, and only the centrifugal force adds a contribution to the force balance opposed to the gravity force.

Re:L2 - How does it work? (2)

Arancaytar (966377) | about 2 years ago | (#41463215)

It's the same force that holds up the moon - centripetal force. The L2 point orbits Earth at the same period (same angular velocity) that the moon does, but further out. That means it moves faster than the moon does.

If the Moon weren't there, a satellite at L2 wouldn't by in a stable orbit: Its centripetal force would be too great.

However, as you said, at that point Earth and Moon pull in the same direction. That means the combined force acts like the gravity of a single more massive body, creating a point further out along the "Earth->Moon->" line where the increased centripetal force is exactly balanced by the increased pull. That sweet spot is L2.

L3 works by the same principle, on the opposite side.

Re:L2 - How does it work? (2)

mbone (558574) | about 2 years ago | (#41463371)

L1, L2 and L3 are pretty easy. The Moon (or whatever secondary body you want, such as the Earth for Earth-Sun Lagrange points) is in some orbit, with some period, about the primary (Earth, in this case). Are there other orbits that have the exact same period ? If the Moon had no mass, the answer would be, no, except for exactly the same mean distance (AKA semi-major axis) from the Earth. With the Moon having a significant mass, things are not quite so simple, but they are not very much harder.

Suppose you are inside the Moon's orbit, on the Earth Moon line. On that line, inside the Moon's orbit, the Moon's gravitational acceleration subtracts from the Earth's, so you feel a little less acceleration towards the Earth, and so your circular orbital period is a little less than it would be in the absence of the Moon. If you go up and down that line, you can find the point where the orbital period (for a circular orbit, with the Moon reducing the Earth's gravity) exactly matches the Moon's original orbital period. That point is the L1 Lagrange point. If you are there, in a circular orbit, you are rotating with the Moon. (It's not stable, but that's another matter.)

Now, suppose you are outside the Moon's orbit on the Earth-Moon line. In that case, the Moon's gravitational acceleration increases the pull of the Earth, so your orbital velocity (for a circular orbit) must be a little faster than it would be without the Moon being present. Again, imagine going up and down the Earth-Moon line until the orbital period (increased by the Moon's gravity) exactly matches that of the Moon. That is the L2 Lagrange point (again, not stable).

L3 is just as easily conceptually - if you are on the opposite side of the Moon, again on the Earth-Moon line, the Moon's gravity again increases the pull of the Earth (by a smidgen, due to its distance), and there is a place on the E-M line, just a smidgen inside the Moon's orbit, where your orbital period is the same as the Moon's. That's the L3 point.

Iron Sky (3, Informative)

Barryke (772876) | about 2 years ago | (#41462909)

I'm surprised that i saw no Iron Sky comments yet.
http://www.ironsky.net/ [ironsky.net] its a B movie made on a budget with remarkable Hollywood quality. Sequal and prequal are in the works, i've heared.

Relevant because its recent (mid 2012), about the dark side of the moon and an US astronaut.
If you want a good laugh about WW2 germans, watch this.

Re:Iron Sky (-1)

Anonymous Coward | about 2 years ago | (#41463759)

Awesome movie. And no, the Nazis will not appreciate us building a station right over their base.

Far side! (1)

mbone (558574) | about 2 years ago | (#41463157)

it would be a space station at the Earth-Moon L2 Lagrange point about 60000 km from the surface of the dark side of the moon.

Please. It's the far side of the Moon. It goes through day-night cycles just like the near side.

L2 is occupied (1)

Zdzicho00 (912806) | about 2 years ago | (#41463495)

ESA Planck space observatory is stationing there already, so buzz off NASA!!

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