NASA Mulling Earth-Moon L2 Point for Mars Staging Station

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.

Comments

Why not build spacecraft there?

[TheMathemagician]

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?

[Anonymous Coward]

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?

[Anonymous Coward]

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?

[Cold hard reality]

So engage in basic research. Why do it indirectly?

Re:Why not build spacecraft there?

[lessthan]

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?

[slashmydots]

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?

[flappinbooger]

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?

[jamstar7]

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?

[Yoda222]

http://en.wikipedia.org/wiki/Military_budget_of_the_United_States It seems that it's possible to throw away one trillion dollars every two years.

Re:Why not build spacecraft there?

[Joce640k]

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?

[SecurityGuy]

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?

[Thud457]

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

really?!

Re:Why not build spacecraft there?

[Yobgod Ababua]

"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?

[Grizzley9]

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

Re:Why not build spacecraft there?

[Anonymous Coward]

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

Actually, no we don't. Given the current technology and political will, it would take much more than a few Trillion to get to anything remotely like that. And for what benefit of all the voters back here? We are already a few T in debt, 5T in just the past 3 years.

While I personally would love to see more emphasis on space, it just aint gonna happen at those levels.

Re:Why not build spacecraft there?

[Anonymous Coward]

Don't worry, I hear they are going to pull a few trillion out of Uranus.

Re:Why not build spacecraft there?

[Grizzley9]

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.

Columbus didn't have to take along all of his food, air supply, fuel, and mountains of equipment. To turn a forest into useful structures, you need a simple blade of an axe and a saw, maybe a pick for the dirt and rocks (and all the req'd labor) and maybe some flint. To turn regolith and rock into simple building supplies suitable for micro-g and airless environ, you need...considerably more. That is unless you have a magic wand. You don't have a magic wand do you?!

Re:Why not build spacecraft there?

[joshuao3]

Amen.

Re:Why not build spacecraft there?

[Cold hard reality]

How many times must it be pointed out that the Americas were so hospitable to man, that they were in fact settled long before Columbus? Once you got there you could be self sustaining within a few weeks. The moon (or space) is inhospitable, there's nothing there, you have to carry everything from Earth at enormous cost. Just build the ship on earth, and assemble it in LEO if it's too large. The total number of launches will be greatly reduced.

Re:Why not build spacecraft there?

[Anonymous Coward]

Correct. The money isn't used up. Productive capacity (man-hours) is being used up instead.

The people who build the rockets could have built something else like improved roads, solar power stations, oil wells, etc. By building the rockets (and then blowing them up) you've wasted that productive capacity.

Re:Why not build spacecraft there?

[jonadab]

> before Columbus sailed to the Americas, there ...
> Wasn't a lot of anything except a lot of forest.

A forest provides substantial quantities of food, water, breathable air, nearly-ready-to-use building materials (all you gotta do is cut it to the shape you want), and a variety of other resources. You can in fact actually live in a forest, with very little in the way of imported supplies. It feels a bit like camping out at first, until you get some infrastructure built, but it isn't quite the same as camping out in the vacuum of space on the far side of the moon.

The only reason to build a spacecraft up there would be to avoid having to get it out of Earth's gravity well in one piece after construction. Admittedly, that's a salient point. There are, however, numerous drawbacks. Notably, you still have to get the entire thing out of Earth's gravity well; the only improvement is now you have the option of doing so piece by piece instead of all at once.

Re:Why not build spacecraft there?

[nedlohs]

1) No the labor and resources the money is a proxy for is instead used up and sent into space.

2) Sure, that's also labor and resources that are used up in destroying things.

Re:Why not build spacecraft there?

[ShanghaiBill]

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

You can never justify an expense just by pointing out that we spend more on something even stupider. A mission to Mars should be justified on its own merits. The fact that we squander money on other things is irrelevant.

Re:Why not build spacecraft there?

[Grishnakh]

Not to mention the coal and oil deposits discovered later.

Columbus didn't know about that stuff, and no one found out about or made use of those things until hundreds of years 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.

You don't know that. It's not like we've done any drilling there; all we've done is collect a few rock samples on the surface. There's probably lots of valuable minerals there, just like we've found many in the earth's crust. Most of our minerals on Earth came from meteorite bombardment; well, take a look at the moon. What do you think all those round things are? And without an atmosphere, the minerals won't be dispersed so much on the Moon, they'll be concentrated at the impact sites. There's probably lots of resources on the Moon we don't know about yet, because we haven't looked. We only recently discovered that there's water ice there; sending up a few astronauts in a half-hearted rock-gathering mission totally missed that important detail.

Re:Why not build spacecraft there?

[Grishnakh]

No, there's many other improvements too; any ship you build on Earth would have to withstand severe stresses in being launched out of the atmosphere. With a ship assembled in space, you don't have this problem; only the smaller assemblies need to withstand such stress, and that's much easier and cheaper. You don't have to build the ship to be as robust in this case.

The other big improvement is that if you have some space-based or lunar-based infrastructure, you can mine the moon or asteroids for materials to build your ships, instead of mining it on earth's surface in someone's backyard, and then lifting it out of the gravity well. Yes, developing that infrastructure is by no means trivial, but once it's in place, it'll pay for itself over time.

Re:Why not build spacecraft there?

[R3d M3rcury]

To turn regolith and rock into simple building supplies suitable for micro-g and airless environ, you need...considerably more.

Exactly. You need a whole infrastructure to support all that stuff and to support itself.

See, this is my minor gripe. Everybody's all about exploring. "We need to put astronauts on Mars! They'll accomplish more in a year than 50 years of Mars probes!" But, to me, this is just more of a circus.

I'd rather see us return to the Moon to stay. That means figuring out how to stay there without getting supplies every month. There's water which we can drink. There's water which we can turn into oxygen. Not sure about the nitrogen part. What will be needed to create a habitat? Above ground? Below ground? Inflatable? Solid? Some combination of the four? How will we handle electricity? Solar? Nuclear? Some combination of the two?

Can we add water to lunar soil and grow stuff in it? How will various tasty earth animals react to 1/6th G. Hell, how will human beings react to 1/6 G? Will we have more/less/the same problems we have with zero G? How can we turn lunar ores into useful metal which we could then use to build stuff?

These are all answerable questions. There's no unobtainium necessary to do any of this stuff. You build up the infrastructure on the Moon. It may take 50 years. But, in 50 years, I'd rather look up at the Moon and see a community. I think that would be much better than some flag sitting among a pile of junk on Mars.

Re:Why not build spacecraft there?

[DanielRavenNest]

Most of the Space Station was built in one crappy old NASA building - 4708 at MSFC, in Huntsville, AL (I used to work there). One side was the factory floor where the module and truss structure were fabricated, the other side was the clean room where the equipment was installed. No way that would cost a $ Trillion. We didn't even have robotics, it was almost all manual assembly. With modern robotics, and "seed factory" machine tools you can start with even less stuff. Seed machines take metallic asteroid metals and turn it into parts. Then robots and remote control and a few live humans assemble those into a wider range of finished machines. Eventually you can process most asteroid materials into fuel, water, oxygen, and whatever else you need.

The advantage, of course, is that Near Earth Asteroid orbits take about 100 times less energy to reach from the Earth-Moon L-2 point than the Earth itself. So it is way easier in the long run to get your supplies from the asteroids. That includes fuel to land on the Moon or go to Mars. EML2 is only 60% of the velocity to reach as the Moon's surface. It's on the way, so you may as well build a "Space Truck Stop" there.

One downside is it is outside the Earth's magnetic field, so humans would be exposed to radiation/solar flares. You will want to do most of the work by remote control until you haul back your first big load of asteroid rock, and can use that for shielding.

Re:Why not build spacecraft there?

[theshowmecanuck]

Most of what we consider "high tech" actually came out of WWII and the Space Race. We're in the last stages now of ideas and technologies that were originated to solve those goals. Now we need new goals.

Basic research is of course needed, but if there is no place to focus it, mankind will get bored of it. It's like making national parks but not allowing people to go to them by either telling us we're not allowed to sully their pristine nature or just plain pricing the costs to visit them too high for the average person . Eventually people will forget about the flora and fauna there and not give a shit if some toad or owl goes extinct. Out of sight, out of mind. (Sorry, no car metaphor.)

The same applies for basic research (for the most part). If people can't see it being applied somewhere eventually, they won't give a rat's ass whether funding is cut for it or not. That is what is happening now. To combat this we NEED some place to apply at least some of what we learn in a spectacular way. Then people, average people, the ones who actually pay for most of the research, can actually see some of what they are getting for the money, and how cool that stuff is; and how it is worth it. Even if only a small part is used in a new space race, it will be enough to help pull funding through for all the less glamorous areas of research.

Stop thinking rationally if you want others to pay for your stuff. They'll only do it if they get something out of it. Directly. In the U.S., national pride is huge. The more you can help fuel that, the more money people will give you. Build a space station. A real space station, not just some "let's stick our toe in the water and do a bit of research" space station. Less of a lab, and more of a one that gives meaning to the word 'station', much like train station, and begins to make space travel routine. Use the research to create that in turn to create whole new technological ecosystems (much like the Apollo series did), and help keep people interested in science so they'll pay for more. The economic benefit (if it isn't offshored by some cynical self serving idiot) is that America will have technology to sell to the rest of the world that it doesn't yet have. This in turn fuels a healthy economy which can then afford to finance basic research. But only if the economic benefits STAY in the country.

Cool sells. Space stations are cool. A nerd in some back lab is cool to many technology lovers, but even then, not all. And certainly not to most of the rest of society. Proof? People pay billions for spoiled sports stars to make millions entertaining them. This gives society a place to vent its anxieties and aggressions (even vicariously). And it is labelled cool and spectacular because it allows those human emotions in full force. Face it, some guy writing equations at a desk, or dolling out solutions from a pipette is pretty dull and boring in comparison. The science that excites is big rocket ships, robots, and risk. Give the crowds what they want, give them Orange Flavoured Tang and Space Opera and they will love you. Give them the spectator sport of science. Then you can pay for basic research. There is a grain of truth even in satire. In this case it is more like a boulder.

Re:Why not build spacecraft there?

[Anonymous Coward]

A few hundred years ago, the same could be said of Manhattan. Or anywhere else in the country.

Re:Why not build spacecraft there?

[Anonymous Coward]

The technology we have today would have looked like magic to Columbus. He was operating 600 years ago, so the technological standards have changed a bit. ...and what seems trivial to us would have been a Big Deal in 1492. Columbus' actions were probably as significant as a moon base would be for us today.

Re:Why not build spacecraft there?

[TheMathemagician]

The costs and resources to achieve this so far outweigh the benefits that I don't believe any rational analysis can justify it. There are many important projects on Earth that could be pursued for a thousandth of the cost and increase US national pride if that's important to you (I'm not American). Irrigating the Sahara? Cleaning up the Pacific Garbage Patch? Or just getting rid of some dictators (Mugabe?).

Re:Why not build spacecraft there?

[Grizzley9]

The technology we have today would have looked like magic to Columbus. He was operating 600 years ago, so the technological standards have changed a bit. ...and what seems trivial to us would have been a Big Deal in 1492. Columbus' actions were probably as significant as a moon base would be for us today.

No, just no. The axe and flint and saw had been around for hundreds if not thousands of years prior and all the tech was well known, working with earth and lumber well known, forest animals well known, etc. Not similar at all.

Re:Why not build spacecraft there?

[Anonymous Coward]

"You don't know that. It's not like we've done any drilling there;"

False.

http://www.universetoday.com/42382/moon-impact-data-and-images-from-lcross-first-glance/

Re:Why not build spacecraft there?

[theshowmecanuck]

You sir, suffer from myopia.

Re:Why not build spacecraft there?

[DirtyLiar]

So engage in basic research. Why do it indirectly?

Because:

1) Most Americans don't WANT to pay for basic research. Why? Because "basic research" has no goals other than the nebulous concept of "expanding human knowledge". The very definition of Waste in the phrase "Waste and Fraud" to most people. And if certain outcomes were promised, likely the definition of the word Fraud too.

2) You never really know what angle of "basic research" is going to pay off. So much of basic research is discovering what is unfruitful. ( Again, the very definition of Waste to the public, and so to polititions also. )

3) Since you don't know what angle of "basic research" is going to pay off, a goal helps to focus effort and avoid going down, intellectually interesting but still nonetheless, "blind alleys".

4) Even when research is directed by a goal, many discoveries are discoveries of accident, when something other than what you expected, happened. Making directed research the most fruitful type of research, as it results in both 'expected' discoveries and 'unexpected' discoveries. While undirected, or basic, research can only result in 'unexpected' discoveries.*

*Ok, that concept may be a bit weak.

Re:Why not build spacecraft there?

[DirtyLiar]

See what I mean? (not talking to themathemagician)

Basic research is seen, by the majority of people, as a waste of resources, rather than an investment in our future. (Like digging a deeper well in anticipation of drought or population growth.)

If we waited to fix all our problems before we concerned ourselves with furthering knowledge, we'd still be living in caves.

I like most of the technologies we have, so I don't want to live in a cave. (Not one without WiFi anyway!)

Besides, that there are other issues that could be addressed with the funds and manpower that goes into something, is not an argument against that thing.

Re:Why not build spacecraft there?

[DirtyLiar]

Crashing is not drilling.

And the little bit of research we have done is hardly a large enough sample to make definitive conclusions about what resources are on the moon.

That's exactly why we crashed that probe into that crater, to see if the hypothesis that there was ice in it's shadows held any water*. (Ahem) Because they / we DON'T know.

*Sorry** for the bad pun.

**Not really

Re:Why not build spacecraft there?

[Cold hard reality]

Most of what we consider "high tech" actually came out of WWII and the Space Race.

Really? Integrated circuits, LCDs, MRIs, the Internet? Digital watches?

WWII did lay a lot of the foundations, but there was a lot of development since.

We're in the last stages now of ideas and technologies that were originated to solve those goals. Now we need new goals.

People have goals just fine. Apple, Intel, Microsoft, Boeing didn't become giants out of nothing. Setting artificial goals simply leads to money being wasted where it isn't most helpful.

>

Basic research is of course needed, but if there is no place to focus it, mankind will get bored of it. It's like making national parks but not allowing people to go to them by either telling us we're not allowed to sully their pristine nature or just plain pricing the costs to visit them too high for the average person
. Eventually people will forget about the flora and fauna there and not give a shit if some toad or owl goes extinct. Out of sight, out of mind. (Sorry, no car metaphor.)

Hire a good PR firm. This huge investment just to get people to give you money for spinoffs sounds like a scam.

The same applies for basic research (for the most part). If people can't see it being applied somewhere eventually, they won't give a rat's ass whether funding is cut for it or not. That is what is happening now. To combat this we NEED some place to apply at least some of what we learn in a spectacular way. Then people, average people, the ones who actually pay for most of the research, can actually see some of what they are getting for the money, and how cool that stuff is; and how it is worth it. Even if only a small part is used in a new space race, it will be enough to help pull funding through for all the less glamorous areas of research.

Or you can have real leadership instead.

Stop thinking rationally if you want others to pay for your stuff. They'll only do it if they get something out of it. Directly. In the U.S., national pride is huge. The more you can help fuel that, the more money people will give you. Build a space station. A real space station, not just some "let's stick our toe in the water and do a bit of research" space station.

The ISS is as real as it gets. You only say it's a toy because we put it up and ... nothing happened. If you put a bigger station there, the same nothing will happen. There's no science to be done there that can't be done better by unmanned satellites and probes.

Less of a lab, and more of a one that gives meaning to the word 'station', much like train station, and begins to make space travel routine.

Routine travel where? Mars, where there's nothing, and you have a launch window every two years or so? Other planets, where it's even more impossible to go?

.Use the research to create that in turn to create whole new technological ecosystems (much like the Apollo series did),

What would we do with even more Teflon?

and help keep people interested in science so they'll pay for more. The economic benefit (if it isn't offshored by some cynical self serving idiot) is that America will have technology to sell to the rest of the world that it doesn't yet have. This in turn fuels a healthy economy which can then afford to finance basic research. But only if the economic benefits STAY in the country.

It doesn't work that way. You borrow money to pay large salaries to talented people. They spent it, some of it on imports. You have less talented people in other fields, so you need to import products to fill the gap.

Cool sells. Space stations are cool. A nerd in some back lab is cool to many technology lovers, but even then, not all.

Re:Why not build spacecraft there?

[DirtyLiar]

The technology we have today would have looked like magic to Columbus... Columbus' actions were probably as significant as a moon base would be for us today.

No, just no. The axe and flint and saw had been around for hundreds if not thousands of years prior and all the tech was well known, working with earth and lumber well known, forest animals well known, etc. Not similar at all.

Large sailing vessels capable of crossing the Atlantic was a relatively new technology (in the West, and a lost technology in the East). The construction of clocks that kept reliable time while shipboard, necessary for accurate navigation beyond sight of the shoreline, was also a new technology. During most of human maritime history, ships were only sailed within sight of land for fear of getting lost (and falling off the world's edge), and because they were not up to weathering the mildest of storms at sea.

Plus confirmation that the world was round made a pretty big splash. (Though that was lessened somewhat by the fact that Columbus did not, in fact, find China (the East) by going west.)

Re:Why not build spacecraft there?

[Cold hard reality]

Manned space _is_ waste and fraud. It will get nowhere except putting some astronaut somewhere and back. Why should taxpayers fund a handful of expensive tourists?

If you have trouble funding basic research, the real problem is lack of leadership.

Re:Why not build spacecraft there?

[DirtyLiar]

Productive capacity (man-hours) is being used up... [and] could have built something else like improved roads, solar power stations, oil wells, etc.

1) So since we're not building rockets, where are those resultant improved roads / infrastructure? They've been needed since long before the 2007 Minneapolis Bridge Collapse.

By building the rockets (and then blowing them up) you've wasted that productive capacity.

2) Only if there is no payoff / ROI from building and using those rockets.

Re:Why not build spacecraft there?

[theshowmecanuck]

I notice you selectively focused on the WWII part. As for the space race tech, yes a lot of that stuff came out of technologies developed by way of that. As for the rest, you are just showing you are another person who can find all sorts of reasons for not doing something, but you just rationalize things more than most. Boeing, Apple, MS, Intel didn't come out of nothing. They came out of a bunch of people doing something they thought was really cool, and generally pointless until a point was found later. Guy like Gates and Woz weren't thinking "next multibillion dollar software company." They were thinking build something cool and they will come. All the original airplane makers started because they like flying. I'll stick to my point of view. I'm tired of people telling me all the things that can't be done or shouldn't be done because of a lack of foresight and imagination.

Re:Why not build spacecraft there?

[Cold hard reality]

I notice you selectively focused on the WWII part.

Sure, because that's generated a lot more technology than the space race. If you want something comparable to WWII, try the cold war.

As for the space race tech, yes a lot of that stuff came out of technologies developed by way of that.

Teflon and... ? and are you sure it wouldn't have come out of other research?

As for the rest, you are just showing you are another person who can find all sorts of reasons for not doing something, but you just rationalize things more than most.

Doing something usually means not doing something else. The manned space program sucks enormous amounts of money that could have been much better spent elsewhere. Can you compare the science return from Hubble, the Voyagers, the various Mars probe up to Curiousity, the Jupiter and Saturn orbiters, the various earth and sun observers, to the ISS? Even to Apollo? Do you realize the cost difference between those programs?

Boeing, Apple, MS, Intel didn't come out of nothing. They came out of a bunch of people doing something they thought was really cool, and generally pointless until a point was found later.

They either did that on their own dime, or that of people who believed in them. That meant they did it not because it was cool, but because they thought they could make money out of it. They were right and they did. If a space station is worthwhile, found a company and build it.

Guy like Gates and Woz weren't thinking "next multibillion dollar software company." They were thinking build something cool and they will come. All the original airplane makers started because they like flying.

No, they saw a business opportunity. No doubt they did it out of love as well, but if it was just that, they wouldn't have grown into such huge businesses.

I'll stick to my point of view. I'm tired of people telling me all the things that can't be done or shouldn't be done because of a lack of foresight and imagination.

It's lack of funding, mostly. If you can convince someone that you have the imagination and ability to build a space station they'll shower you in cash and wait patiently until the return you've foreseen appears.

Re:Why not build spacecraft there?

[Grizzley9]

Plus confirmation that the world was round made a pretty big splash. (Though that was lessened somewhat by the fact that Columbus did not, in fact, find China (the East) by going west.)

2000 years of history would disagree with you: http://www.livescience.com/16468-christopher-columbus-myths-flat-earth-discovered-americas.html

Re:Why not build spacecraft there?

[DirtyLiar]

Manned space _is_ waste and fraud. It will get nowhere except putting some astronaut somewhere and back.

Not only does what you say prove my point, it is also untrue.

Why should taxpayers fund a handful of expensive tourists?

Because, oh ye of little insight, there are NUMEROUS benifits of spaceflight.

In actual fact the term “spinoff” was specifically invented to describe specific technologies developed by NASA for its missions that are transferred for commercial use or some other beneficial application.

Just off the top of my head, some of those technologies include:

Do you like computers, cell-phones, or palm-tops? Computers were a direct result of needing near instantaneous calculations using data that would be unknown until the moment it was going to be used. The invention of both the transistor, and the computer chip can be traced back to the need to make components as compact and light as possible. As was their subsequent miniaturization.

How about the convenience of microwave ovens, or freeze dried food? Both direct results of the need to heat food without the possibility of a fire, and the need to preserve food and reduce total weight.

Do you have a digital cameras? Use the Internet at all? Watch / listen / use Satellite Television / Radio / International Phone Calls?
All originally invented for use in the space program.

But let's see what a little research turns up...

NASA technologies that help society at large.

The suits of the lunar astronauts were liquid cooled and lead directly to the invention of technology (at NASA’s Johnson Space Center) used for treatment medical ailments such as burning limb syndrome, multiple sclerosis, spinal injuries and sports injuries.

Another Johnson Space Center project resulted in a lightweight breathing system for firefighters. Now widely used in breathing apparatuses of all types.

NASA research has resulted in safer, studier school busses.

Both GPS and IGDG (Internet based Glogal Differential GPS, a system designed to control real-time streaming GPS data).

NASA's Langly Research Center developed a low cost ballistic parachute system that lowers an entire aircraft to the ground in the event of an emergency. It has saved over 200 lives so far.

Using technology developed to clean up rocket-fuel spills, two NASA scientists, along with the University of Central Florida, created EZVI, a chemical effective in the environmental clean up of underground pollutiants.

The development of a medical device used in the early detection of cateracts and other eye diseases, diabetes and current research is being held to see if it could be an early warning system for Alzheimer's.

A device that has been used to restore 19th century paintings.

A food safety system that, 25 years after NASA developed it, was adopted by the FDA and Agriculture Department, and managed within a single year to halve the previously growing cases of Salmonella in the US.

Technology designed to see the surface of Mars has been used to image otherwise invisable writing on badly burned and stained Roman manuscripts.

Both the EKG and EEG, used in hospitals and emergancy rooms around the world, were developed to monitor astronauts.

Ultra-small electronic circuits that enable countless medical advances, such as bone-density measurement technology and miniaturized heart pumps.

Plastic-like metals used in jewelry and sporting goods

Aviation safety systems.

Intelligent ovens that allow you to begin dinner before you even get home.

Airbags

Insulin pumps

Olympics-caliber swimsuits, the LZR line, launched in February 2008, quickly became de rigueur for competitive swimmers: more than nine out of 10 gold-medal winners at the Beijing Olympics six months later wore them.

Memory metals that flex and recover their shape in response to heat are used in shower

Re:Why not build spacecraft there?

[DirtyLiar]

2000 years of history would disagree with you: http://www.livescience.com/16468-christopher-columbus-myths-flat-earth-discovered-americas.html

Since I never said that Columbus discovered that the earth was ,spherical (Not round as your indicated article states, a round earth would not rule out a flat earth. For instance, the quintessential wheel is both flat AND round.), for your statement to be true, the circumference of the earth would not only have to have been calculated by the Greeks, but then confirmed by them too by the circumnavigation of the world.

Or are you saying that the reaction of the mass of European people had been prognosticated some 1700 years before Columbus was born?

Re:Why not build spacecraft there?

[Cold hard reality]

You're called DirtyLiar, so probably a troll. I'll make this short.

Just off the top of my head, some of those technologies include:

Do you like computers, cell-phones, or palm-tops? Computers were a direct result of needing near instantaneous calculations using data that would be unknown until the moment it was going to be used. The invention of both the transistor, and the computer chip can be traced back to the need to make components as compact and light as possible. As was their subsequent miniaturization.

Computers were invented in WWII. Transistors were invented in 1947. Integrated circuits were invented in 1949, but not used on the Saturn V.

How about the convenience of microwave ovens,

Available since 1947.

or freeze dried food?

WWII tech. I'll stop now.

Re:Why not build spacecraft there?

[DirtyLiar]

You're called DirtyLiar, so probably a troll. I'll make this short.

Ah, I see you are easily distracted by appearances. Not a trait I'd brag about.

And it's not what "I'm called" it's what I call myself in a bit of self-deprecating humor. A trait you seem unacquainted with.

But I also see that YOU call YOURSELF the "Cold hard reality". Which is indicative of low self-worth, and low self-confidence, while at the same time being a bit (not really a bit) of a blow-hard that's trying to fool people into giving himself unearned credibility.

Otherwise, what's with the name?

Computers were invented in WWII.

Ah, you got me. It's true, they had single purpose electronic calculating machines that used thermionic valves and filled entire rooms towards the end of WWII. Even though the ENIAC is considered the first generation of modern computers.

No chance of one ever seeing the inside of a rocket, but nonetheless they existed.

Transistors were invented in 1947.

Transistor, not transistors. The first transistor was invented in 1947, but I will concede your point.

Integrated circuits were invented in 1949, but not used on the Saturn V.

Can you back that up with data? Everything I find says that they were invented in 1958.
There is mention on Wikipedia of an "integrated-circuit-like semiconductor amplifying device" from 1949, but that article also points to 1958 as the year they were invented, with a first practical demonstration on September 12th of that year. Besides, I thought you considered Wikipedia to be a bad source of information.

That NASA doesn't use a technology immediately after it's discovery is irrelevant to the question of what prompted their development.

How about the convenience of microwave ovens,

Available since 1947.

To quote you: "Wrong. Just Wrong."
In 1945 it was discovered that microwaves could heat food (A melted candy bar in a man's pocket, does not an oven make.) But the first microwave oven wasn't commercially available until 1954.

That discovery is no more a microwave oven than an open fire is an oven. Hardly "Available since 1947".

Besides, the first microwave ovens weighed 750 pounds and stood five feet, six inches. Again not likely usable in space.

or freeze dried food?

WWII tech.

They freeze-dried blood plasma and medications like penicillin. Not food. Too many nutrients were lost in the process to make it attractive in WWII.
It wasn't until 1938 that Nestle invented a viable process for Freeze Drying food, specifically for NASA.

'll stop now.

Perhaps you should, your track record (40%) isn't that good.

It is probably best that you do stop here and ignore the other 99 examples I gave. Or is it that you realize that your percentage can only go down from this point?

Let me help you out though: Apparently NASA was unrelated to the development of GPS, though that is not true for IGDG. And I was SURE you were going to nail me for international phone calls, at which time I'd point out that oceanic cables are fragile, difficult to repair, and laid over volcanicly active regions so have a short life span.

Why don't you focus on the part after the But let's see what a little research turns up.... You know, 90% of my examples?

Me, well, you've shown to me that some of the earliest things I learned about NASA are not quite true, and need to be tweaked a bit to be true, and it's time I update my knowledge about it.

Dark side, really?

[pmontra]

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?

[alex67500]

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?

[trout007]

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?

[K. S. Kyosuke]

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?

[benjfowler]

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

Re:Dark side, really?

[Hillgiant]

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?

[marsu_k]

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?

[pmontra]

https://www.youtube.com/watch?v=328WhjAXpcs 42:24, thanks

Re:Dark side, really?

[Anonymous Coward]

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

Re:Dark side, really?

[Zephyn]

Yep. And ZZ Top would have you believe there's a shack just outside of the Lagrange point already.

Re:Dark side, really?

[Bill Currie]

There's always Earthdark :)

But yeah, I too twitched when I read that bit.

Re:Dark side, really?

[Lucractius]

Which could be done really cheaply.
Comsats are pretty much off the shelf these days, and GEO comsats are already hardened to more radiation due to their increased height. Further hardening might not be necessary depending on the design and capabilities.

I still dont know why we havent built a Lunar comms and navigation satellite constellation. It would be trivially within the budget of a number of nations, companies, and could have even been incorporated into the budget of several large science missions. This doesnt need to be an irridium scale network of dozens and dozens of satellites, continuous coverage could be accomplished with just 6 sattelites like the small and cheap (by satellite standards) SN-100s from Sierra Nevada in order to keep the weight down since the lunar orbit boost would cost even more. But since they are small enough to be secondary payloads they could be bunched together on a single booster and sent to the moon together to cut down on launch costs as much as possible. And thats before exploring options like using hall effect thrusters like the SMART-1 mission did and getting to the moon the long slow way to be even more efficient for launch costs.

Re:Dark side, really?

[tzot]

Well, Pink Floyd aren't really at fault (unless one didn't listen to the lyrics, and only cared for album and song titles; even then, “Eclipse” should be enough).

I believe that everyone would agree that a more correct term would be “the hidden side of the Moon”, but it's not as catchy, so let's say “the far side of the Moon” which is as catchy (rhyme-wise) and as literal as it can be for our Earth-centered POV.

Dark side of the moon...

[Ecuador]

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...

[multi io]

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...

[Anonymous Coward]

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...

[pmontra]

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...

[Anonymous Coward]

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...

[multi io]

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...

[Megane]

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

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...

[WGFCrafty]

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

Re:Dark side of the moon...

[AliasMarlowe]

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, 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, 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...

[Anonymous Coward]

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...

[lobotomir]

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...

[Ecuador]

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...

[Tim the Gecko]

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 will be at the Earth-Sun L2 point.

Re:Dark side of the moon...

[camperdave]

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...

[mbone]

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...

[1u3hr]

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

I thought he was just an idiot. But I think he was referring to the farside at night. During those 2 weeks it indeed would be extremely dark, without any earthlight. But the nearside at night would also be pretty dark when the earth above it was full dark, once every 24 hours for an hour or so.

Re:Dark side of the moon...

[RockClimbingFool]

Stockpiling fuel at the Earth-Moon L2 makes sense if you never make propellant in orbit. Although I believe making a propellant depot at an altitude slightly higher than Earth GEO is a better investment.

I know NASA isn't in the commercial satellite repair business, but at GEO you could have your depot at a reachable location and gain valuable experience trying to revive dead satellites in your spare time. Reopening comm links could provide a small source of revenue, but the experience of doing those types of activities in orbit seems invaluable to me.

If you discover a make to make fuel or oxidizer on the moon, even if its terribly inefficient, then you have some trade studies to analyze. At several thousand dollars per lbm launching cost from the earth (due to the large gravity well and atmosphere), there is some break even point for launching inefficiently manufactured lunar propellant to either L2 or GEO from the moon (due to smaller gravity well and no atmosphere).

The ideal situation would be to have autonomous propellant manufacturing on the moon. Then have automated deliveries to the in orbit propellant depots. That would be a pretty complicated setup that would either require permanent workers (and the supporting moon base) or at least temporary ones (that would require lander, temporary habitats, etc).

Re:Dark side of the moon...

[Anonymous Coward]

You know what, you're a bit of a {insert tailored made excuse for this plausible excuse for a /.er}

You're the type of person who couldn't possibly concieve of a dark and mysterious white person I'd bet. You know, the usage of the word dark in reference to things unknown. i.e. "to be kept in the dark". Before you start to panic, no, this doesn't involve throwing a blanket over someone.

*sigh*

As you well know, the moons orbit and rotation cancel out resulting in one side constantly facing the earth and one side constantly facing away. As such it is not observable from Earth, ever. Unlike the Olympus Mons as Mars orbit/rotation means that, over time, all of it may be witnessed from Earth (provided the right tools are to hand).

This is not possible for the Moon, up until the Space Race man had never, in his entire existance, seen the otherside of the moon and hence it being commonly known as dark.

You may be up to date with your science lessons but you may wish to brush up on your English and History.

As for "you seem to be having a problem finding a name..."... seeing as I explictly stated that I wasn't certain I'm staggered you find it necessary to repeat the point. I'd accuse you of using a Straw Man but I'd hate for this to devolve into and explanation of agricultural wards.

Re:Dark side of the moon...

[Megane]

The ideal situation would be to have autonomous propellant manufacturing on the moon.

That would first require something on the moon with enough energy to be used as propellant. So far all we can get from the moon is a bunch of rock with a little bit of H2O ice at the poles. About all we could do is set up some solar panels and make 2H2+O2. But that's only a minor detail. (inb4 He3 which we won't have the technology to use as fuel for decades to come)

Re:Dark side of the moon...

[multi io]

I thought he was just an idiot. But I think he was referring to the farside at night. During those 2 weeks it indeed would be extremely dark, without any earthlight. But the nearside at night would also be pretty dark when the earth above it was full dark, once every 24 hours for an hour or so.

I don't know what you mean. When the earth as seen from the moon is fully dark, the nearside of the moon is obviously fully illuminated (unless there is a lunar eclipse going on). And when the nearside of the moon is fully dark, the earth as seen from the moon is fully illuminated (unless there is a solar eclipse going on), so the night/near side of the moon would receive a maximum amount of earthlight. And both these things don't happen once every 24 hours or so, but once every 2 weeks or so. Between those two extremes, you have a partly darkened nearside receiving earthlight from a partly illuminated earth. But to see a part of the lunar surface that's in total darkness, receiving no light from either the sun or the earth, an observer has to get away from the earth, e.g. into lunar orbit or to the L2 point. In the L2 point, since the earth is invisible all the time, any observable part of the lunar surface that's not lit by the sun would be in total darkness. Maybe I was an idiot because this is all sort of off-topic. But it just occurred to me that the moon would be a visually striking object when seen from the L2 point because of these phenomena (in addition to the fact that it would appear 6 or so times bigger in the sky than as seen from the earth).

Re:Dark side of the moon...

[1u3hr]

I don't know what you mean. When the earth as seen from the moon is fully dark, the nearside of the moon is obviously fully illuminated

Yes, I didn't think it through.

The earth is stationary in the moon's sky, and its phase would take a month to change, and be full at lunar midnight. But you'd see the continents spinning around once an earth day, I confused that with the phase.

Sorry about the "idiot" stuff, but your use of "dark side" was pretty confusing; it might have been correct literally, but the (real) idiots have made that term synonymous with farside.

Re:Dark side of the moon...

[camperdave]

The Moon's shadow on the Earth is about the size of a typical hurricane, so even during a solar eclipse, a Lunar nearside night is going to be fairly well illuminated by Earthlight.

Re:Dark side of the moon...

[Anonymous Coward]

Are you the same AC? I hope not, because the first AC goes out and declares that of course it is the dark side because there are no signals from earth - duh! Then the next AC starts about how dark = mysterious/unknown - duh!
Let's get another AC here to tell us what it is after all...

Re:Dark side of the moon...

[DirtyLiar]

You want to say FAR side of the moon

Not true. The "Dark side of the Moon" traditionally refers to the far side of the moon, which is "dark" only in the sense that you can not see it, and so neither send or receive information from it.

For something to be X miles above the DARK side of the moon, it would have to be orbiting the moon.

Not true again. An object orbiting the earth, but further away than the moon, could easily be fixed X miles over the dark / far side of the moon.

Similarly, objects locked in the correct Lagrange-Point would also be stationary as far as the moon is concerned. (The earth too, for that matter.)

But, no, you should not be editing something like slashdot causing the readers to pull their hair.

Hmmm. Something about pots and kettles springs to mind.

Re:Dark side of the moon...

[DirtyLiar]

Let's get another AC here to tell us what it is after all...

That's (apparently) your function here.

Re:Dark side of the moon...

[DirtyLiar]

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... Of course the wikipedia article is useless...

How about NASA? Is that an official and scientific enough source for you?

1) Here's the definition of "Darkside Of The Moon" provided by the High Energy Astrophysics Science Archive Research Center arm of NASA.

2) Fourth paragraph, 2nd sentence to the end (better yet, search for it.), in this educational material for young children provided by NASA.

3) From a 2010 open "Ask an Expert" chat session: "There's really no dark side of the moon, it's just the side we never see." Even when 'debunking' the term they define it as "the side we never see".

I suspect the (incorrect) usage of the term "dark side" might be older than radio signals.

I think it odd that while you claim someone else is redefining the term, you also acknowledge the historical meaning IS exactly what they claimed it to be.

And since (as we both agree it is) the traditional meaning of the "dark side of the moon" is "the side of the moon we never see", that makes "the nightside" the actual redefinition of "the dark side of the moon".

BTW, that Fox News said something does not make it false. Just highly unlikely! ^_^

Re:Dark side of the moon...

[DirtyLiar]

and you avoid risk of a colossal failure at single point in time

You do understand that this is in a total vacuum, subject to cosmic rays, soar mass ejections, x-rays, micro-meteorites, and regular sized meteorites?

And that there will be large stores of pure (and highly explosive) oxygen in near proximity to hydrogen or some other rocket fuel AND living quarters?

Your definition of "colossal failure" apparently differs greatly from mine. That such a structure would exist at all is an invitation to "colossal failure".

Re:Dark side of the moon...

[DirtyLiar]

That would first require something on the moon with enough energy to be used as propellant.

Actually, in low enough gravity (like in orbit), even dust or rocks could be used as propellant by ejecting them in the opposite direction you wish to travel in.

Just like getting in a rowboat and walking from the front to the rear will propel the boat forwards. If you then jump out, the energy (I'm tempted to call it momentum, but that's probably wrong) of your leap will propel the boat even further, even faster. In space, where there is no air or water friction to slow you down, such tactics will be even more successful.

Additionally, rail-gun technology has long been considered an option for raising objects and vessels into moon orbit, or even propelling them to earth.

Best yet, the "real" fuel in both cases is just electricity. In one case moving mass out of the ship, in the other moving the ship it'self via electromagnetism.

Re:Dark side of the moon...

[DirtyLiar]

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

Wha...huh?

Not the side facing the Sun.

Or the side facing the Earth, for that matter.

Just because the sky is black does not mean there is no light. In fact, on the side facing the sun it's glaringly bright. Except for the shadows, which are freezingly cold.

Re:Dark side of the moon...

[Anonymous Coward]

http://www.pink-floyd-lyrics.com/html/eclipse-dark-lyrics.html

Good for a lot of reasons...

[Genda]

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...

[FTWinston]

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...

[art6217]

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

Re:Good for a lot of reasons...

[Anonymous Coward]

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...

[Framboise]

>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...

[Anonymous Coward]

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...

[Anonymous Coward]

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...

[BadgerRush]

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...

[Anonymous Coward]

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...

[mbone]

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 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...

[mbone]

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).

Re:Good for a lot of reasons...

[RNLockwood]

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

I think that the energy (and mass of fuel) required to launch from L2 is a lot less than L1 since l2 is on a gravitational "tether" of about 450,000 km (more or less). launching at a particular spot in the orbit means it has a considerable initial velocity.

Re:Good for a lot of reasons...

[Grishnakh]

Seems to me that if you're going to go to all that trouble, it'd be easier to just build a base on the moon for most operations, except those things which absolutely must be done in zero-g.

save trillions

[GarretSidzaka]

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

[jkflying]

ISS isn't sufficiently shielded to be outside of LEO

Re:save trillions

[Megane]

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

[Anonymous Coward]

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.

Re:save trillions

[BadgerRush]

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

[BadgerRush]

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

[Anonymous Coward]

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

[Anonymous Coward]

No what we really need is to build a "Homeworld" type ship that can build it's own smaller ships and ore collectors, do research, and build a defense force.

Re:save trillions

[GarretSidzaka]

very good point. but at the lagrange they could mount reactor(s) to power faraday cages over some of the habitat modules

Re:save trillions

[Anonymous Coward]

It wouldn't take damage from VASMIR, but it would take damage from any thruster powerful enough to get it out of the gravity well (aka, not VASMIR).

Sounds like a Death star!

[Anonymous Coward]

I didnt know Darth Vader had been employed by NASA.

Re:Sounds like a Death star!

[nozzo]

That's no moon!

L2 Because of it's purpose

[brunes69]

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.

Deeply impressed...

[Anonymous Coward]

... 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?

[Anonymous Coward]

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

[Anonymous Coward]

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

Romney wants Florida

[Anonymous Coward]

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

[Anonymous Coward]

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

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

Re:Windows that open in jet airplanes

[mbone]

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

Re:Good for a lot of reasons.

[Anonymous Coward]

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

Why not LEO, and use the ISS?

[captainpanic]

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?

[hackertourist]

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?

[captainpanic]

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?

[Anonymous Coward]

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?

[ceoyoyo]

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?

[captainpanic]

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?

[ceoyoyo]

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.

Re:Why not LEO, and use the ISS?

[Cold hard reality]

Stages introduce complexity which means weight and more things to go wrong.

manned space stations in L2 also introduce complexity. A lot more complexity, in fact.

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.

Leave a full fuel tank where you wanted to keep your station.

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).

Think how much it would cost to keep your L2 station supplied. Launches there are much more expensive per kilogram. Nor do you really need a station, assemble the spacecraft in space and then send everyone home. Voila - no maintenance costs.

There are probably also advantages to slingshot maneuvers around the Earth and moon from L2.

A lunar slingshot isn't very worthwhile (and you could do it from LEO, too).

And you don't need to dodge space junk and other satellites.

It's not like they have to duck every five minutes. That problem almost doesn't exist.

You can also probably arrange for constant sunlight, meaning constant power.

Yes, your panels are more efficient. But they're also a lot more expensive since you launched them higher. Easier to launch more panels.

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.

So start the ship unmanned on its way and rendezvous with it later on. No need for a station.

Re:Why not LEO, and use the ISS?

[hackertourist]

You'd have to move it from its current inclination of ~51 degrees to about 23deg.
WAG and I'm not a rocket scientist: 51-23=28, sin(28)=0.47 so you'd have to do a delta-V of about 0.47x orbital velocity which is 12000 km/h applied to 100 tons. A Space Shuttle burns ~1900 tons of fuel to get 100 tons up to 25000 km/h, so call it 1000 tons of fuel to shift the ISS.

To provide a long term goal

[Anonymous Coward]

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

[ByOhTek]

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

[Cold hard reality]

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

Re:To provide a long term goal

[Cold hard reality]

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

[Anonymous Coward]

Why don't we duct tape your fingers together so you can't type? Moron.

Why not modular?

[Lumpy]

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?

[jamstar7]

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.

Re:Why not modular?

[Anonymous Coward]

Ahh I see and the ORbit is determined by the design. so Modular design forces them to use shitty orbits. Got ya.

Glad to see you are a super rocket scientist.

So what colors allow us to go faster mister rocket scientist?

Waste of money, go Mars Direct

[kbonin]

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

[Anonymous Coward]

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.

Re:Waste of money, go Mars Direct

[Mr. McGibby]

Sure, if the only goal is to get to Mars, then other plans might make more sense. What we're trying to do here is create a spacefaring society. Mars is part of that, but not the only thing. Zubrin talks a lot about gravity wells, yet he proposes that we go directly from one to another.

Re:Waste of money, go Mars Direct

[kbonin]

I understand the argument, and frankly I agree. However, given the political nature of the non private space programs, I also believe that other than a real push to Mars, the US program is destined to remain like the Shuttle and ISS - little more than jobs and pork delivery. Think of how little science has been accomplished by STS and ISS programs, and few actually reusable components other than the STS RS-25 and SRB, which are still restricted to US government program use.

If we fund a moon base or Lagrangian station, we're basically out of public money for space and stuck on this rock.

Going to Mars will not only inspire people again, it gives us somewhere we shortly place self-sufficient humans to live, which is far more important long term to the species. Publicly fund a Mars Mission and private money will quickly follow you there. You want a 'space faring society', Space X is a better program to orbit, Bigelow has something interesting to put there, and programs like VASIMR are exploring how to move us out further.

Re:Waste of money, go Mars Direct

[Grishnakh]

If you just want a place for humans to live, the Moon can do that too, and it's a lot closer. What does Mars have that the Moon doesn't? An atmosphere? Mars' atmosphere is too thin to be of any use. Gravity? Mars has 1/3g, Moon has 1/6g; BFD, they're both pretty low. A magnetosphere to protect you from radiation? Neither one has it. Resources? Maybe I'm missing something, but we don't seem to know a lot about either one as far as resources, because we haven't investigated them that much. It's not like we've done any drilling on either body, and we only recently discovered water ice on the Moon. The moon is really close by and will be much easier to travel to.

Re:Waste of money, go Mars Direct

[Anonymous Coward]

What does Mars have that the Moon doesn't?

A complete set of the volatile elements needed to support life. The moon may still have it in the subsurface regolith, since regolith has low permeability and gasses would likely be trapped, but this is unproven and it is technically difficult to set up a mine to find out. A lunar polar base will most likely need to have phosporous shipped from earth for food production (a difficult and expensive prospect since all lunar landings must be done entirely with rocket power).

Mars' atmosphere is too thin to be of any use.

You made that up. The martian atmosphere is one of the most promising parts of the planet for in-situ resource utilisation. It can be used to produce fuel, breathable gas, CO2 for food production and Argon for various laboratory and industrial purposes.

Gravity? Mars has 1/3g, Moon has 1/6g;

No-one knows how much gravity humans need to maintain health. If you have found the answer, please publish your research. BUT 1/3 is twice as high as 1/6, so don't conflate the two.

A magnetosphere to protect you from radiation? Neither one has it.

Mars does not have a global magnetic field, but it does have localised magnetic fields. These fields deflect ionising radiation away from some parts of the surface and towards others. Thus it functions much like on earth but with small spots of low and high radiation instead of our two highs and mostly low. The protection offered is lower but landing sites can be chosen appropriately.

Resources? Maybe I'm missing something, but we don't seem to know a lot about either one as far as resources, because we haven't investigated them that much.

You are. Don't make positive statements if you haven't at least taken a few minutes to research the question. ;)

It's not like we've done any drilling on either body, and we only recently discovered water ice on the Moon.

We haven't done drilling on either body, but we have a number of meteorites of known origin (but not actual location on the planet) as well as numberous samples taken from known locations on the moon. Smashing a probe into the moon and studying the plume is also a valid substitude for drilling. The lunar surface is completely devoid of volatiles such as carbon, hydrogen and phosphorous, except for a few permanently dark spots at the south pole and (theoretically, but with we're confident) the north pole. We also suspect volatiles several metres below the surface, but this is unproven and difficult to extract, as already mentioned. Mars is known to have all the needed volatiles. While martian geology is less studied than lunar geology, rovers have identified known minerals and we have a reasonable idea of what to expect. Water ice, since you mentioned it, is known to exist on mars in the polar regions and all but certainly in glaciers in Hellas Planitia. Subsurface liquid water is thought to exist near the equator where there are no glaciers. Hydrated minerals are also known to exist.

The moon is really close by and will be much easier to travel to.

Mars is easier to travel to. Because of aerobraking, the delta-v from earth for a mars landing is lower than a moon landing. The one caveat is longer travel time.

Save L2 for astronomy!

[Anonymous Coward]

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

No they won't

[Hentes]

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

[kiriath]

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

For Shame

[Anonymous Coward]

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...

[wonkey_monkey]

...that's a gateway spacecraft!

Psychological effects

[necro81]

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?

[bluesky74656]

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?

[Barryke]

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?

[Framboise]

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?

[Arancaytar]

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?

[mbone]

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.

Re:L2 - How does it work?

[Anonymous Coward]

Thanks for that. L1,L2,L3 seem reasonable to me. I can't figure out L4 and L5 tho. I've googled but haven't found an explanation that clears them up very well. Does anyone have a good link? I'd really like to learn how the forces balance out at L4 and L5.

Re:L2 - How does it work?

[thrich81]

I read all the other answers and they are accurate but not complete. L2 and L3 are not points of stability in the sense that you can put an object there and it will stay there -- they are metastable in that the forces on the object are balanced, but balanced in the sense of balancing on a knife edge. A small perturbation inward or outward from L2 or L3 will be amplified and the object leaves position. That said, there are stable trajectories of the object such that it can "orbit" L2 or L3 such that it stays nearby. Thus there is an regular motion of the object where it trades potential energy for kinetic in a repeatable pattern, sort of how an object in an elliptical orbit around the earth does the same. Sorry, I don't know the details and don't have time to go deeper -- I had to do a quick review on Wikipedia to get this far.

Re:L2 - How does it work?

[jpvlsmv]

IANAE (snip) this combined vector is canceling the centrifugal force of orbiting earth+moon.

This gravitational attraction is creating the centripetal acceleration that creates a closed orbital loop. There is no centrifugal force, only the intertial tendency to move in a straight line.

--Joe

Re:L2 - How does it work?

[cryptizard]

I'll just leave this here http://en.wikipedia.org/wiki/Centrifugal_force_(rotating_reference_frame)

Iron Sky

[Barryke]

I'm surprised that i saw no Iron Sky comments yet.
http://www.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

[Anonymous Coward]

Helium 3? Oh.... Thats ours.

Far side!

[mbone]

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.

Re:Far side!

[LanMan04]

"Dark" refers to radio-dark (from the point of view of the Earth), not absence of sunlight.

Are we sure this is a good idea?

[flappinbooger]

https://www.google.com/search?q=ingo+swann+penetration

You know, that's near the DARK side of the moon...

L2 is occupied

[Zdzicho00]

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

Re:L2 is occupied

[Hentes]

Satellites aren't put at the Lagrange points themselves but on orbits around them.

Re:L2 is occupied

[Anonymous Coward]

The Plank is in the Earth Sun L2 not the Earth Moon L2.

Re:L2 is occupied

[bitingduck]

Herschel and Planck are at Earth-Sun L2 (solar orbit), not Earth-Moon L2 (earth orbit)

Better source...

[Ecuador]

Also, instead of wikipedia we could link to an actual source. E.g. Phil Plait's excellent blog: http://www.badastronomy.com/bad/misc/dark_side.html

Re:Better source...

[Anonymous Coward]

So you admit that dark side of the moon is a common (as in lay man) way of reffering to the far side of the moon then? You also understand the differnce between dark (no light) and dark (unknown).

What's your beef again?

Re:Better source...

[Anonymous Coward]

> What's your beef again?

"Popular misconception is popular."

something diffrent

[Anonymous Coward]

Call me crazy but I would rather a Lunar cycler.

Getting to Earth-Moon L2 is cheap.

[Anonymous Coward]

Initially I thought this was a crazy idea, but I looked it up and getting to the Earth-Moon L2 point is cheaper than geostaionary orbit.

http://en.m.wikipedia.org/wiki/Delta-v_budget

While it does cost a little to stop and park there, stopping at the Earth-Moon L2 point barely adds to the cost of moons farther abroad.

Even nicer if you have a space capsule that is built to handle the areobraking speeds (like the Orion) it is nearly as cheap fuel wise to return to Earth as it is to return to Earth from near earth orbit.

So in Earth-Moon L2 we have a location that our existing rockets can get to. A awesome location for connecting with unmanned craft ( The interplantary supehighway) and a cheaper location to park than low Earth orbit.

Does it really make sense to put a station there? I don't know but putting a supply depo in the pass doesn't sound stupid.

Other Europeans had sailed to America before

[fantomas]

Why this obsession with Columbus? he wasn't the first European in recent historical times to sail to America...

Re:Other Europeans had sailed to America before

[Anonymous Coward]

Because he came here and *stayed* -- or at least triggered the ongoing settlement that led directly an inexorably to modern America.

Yes, we're all suitably impressed that you know he wasn't the first sailor to arrive here, but its ignorant (or disingenuous) to minimize his historical significance.

Re:Other Europeans had sailed to America before

[DirtyLiar]

Why this obsession with Columbus? he wasn't the first European in recent historical times to sail to America...

Not to take away from their accomplishment, but a few lucky Norse sailing the North Atlantic by island-hopping their way to Canada, in boats not designed for sailing out-of-sight of the coastline, who managed to make the trip a handful of times while avoiding being sunk or capsized mid-ocean, means that the Norse had the 'Theoretical' capacity to sail to the Americas (meaning that most trips would probably fail). But lacked the means to actually settle and trade with this "New World".

Columbus, on the other hand, proved that Europe (or at least Spain) had achieved the technology necessary to create AND trade with colonies in "The New World".

Leif Ericson and Eric the Red's children get an A+ for effort and bravery (foolhardiness?), but an F for staying power.
Columbus get's a B+ for bravery, and an A+ for staying power.

The impacts of each on humanity of both are both plain and obvious. The Norse discovery and attempted colonization of the Americas had no impact, beyond the the deaths of a few Norse. An interesting historical side-note. The 'Colombian' discovery had a huge impact on Europe, the then dominant human culture (in terms of population, and land, and trade, and wealth), and on history following this (re)discovery. A pivotal point in history with many historical repercussions, many of which are still playing themselves out today.

That's why the 'obsession' with Columbus.

Nuclear Power?

[Dripdry]

Forgive me if this has already been covered, but does this mean that if we sent up materials for it that it might be possible to build ships with nuclear-powered engines, since firing them won't be on earth?

This could be awesome news in terms of getting fuel up there.

There is no dark side of the moon.

[Anonymous Coward]

.. as a matter of fact, it's all dark.

from the surface of the dark side of the moon?

[angel'o'sphere]

The moon has no dark side ...