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> Hmm, has anyone considered moving the ISS to earth-moon L2?

This idea comes up all the time on r/space. It can't be done. The ISS is not safe out there. It does not have enough radiation shielding nor is it sturdy enough, nor would you be able to accelerate it out there, etc. Making the modifications necessary to do so would cost much more than just building a new ship.




L2 sounds like a big boondoggle to me. It's like the ISS part two. A base on the lunar surface would be able to use lunar soil for radiation shielding. Put a linear accelerator out there to launch things into orbit, and you dramatically reduce the travel costs to get there and back. (Since you won't have to haul as much fuel for return up there.) In addition, O2 can be extracted from lunar soil, which would reduce the return fuel payload to almost nothing.


The convenience of being on a giant rock versus a sitting duck in space can't be understated, either. It makes a lot of things a lot less complicated, especially supplying the base. The deceleration and coupling that ships to the ISS have to go through would be completely negated on the moon - all you have to do is land something relatively close (within a few hundred yards, maybe?) to the base and you're set. It's like threading a needle versus hitting the broad side of a barn.

Fuel costs would obviously be greater, but not all that much, and once there is a permanent mobile presence in near space, the fuel cost will really just be relegated to getting from the surface into orbit (which is most of the fuel cost anyway).

The reality (sad, unfortunate, or otherwise) is that getting into space is expensive, but it's ridiculously cheap compared to some of the other things the US wastes money on.


Fuel costs would obviously be greater, but not all that much

Fuel is just a small fraction of the cost anyhow. Also, you could build "cycler" craft using ion or plasma thrusters that could ferry crew modules from LEO to the moon and back.

The convenience of being on a giant rock versus a sitting duck in space can't be understated, either. It makes a lot of things a lot less complicated, especially supplying the base. The deceleration and coupling that ships to the ISS have to go through would be completely negated on the moon - all you have to do is land something relatively close (within a few hundred yards, maybe?) to the base and you're set. It's like threading a needle versus hitting the broad side of a barn.

There's a lot of valuable payloads you wouldn't have to actually land. You could ship frozen water up there in a projectile designed to keep it in a super-cold, super-hard state using liquid nitrogen as a boil-off coolant, and also clad it in armor and partially shield it from impact. Then a rover could go and retrieve the frozen water capsules. Even better, have a few shipments consist of frozen, dampened potting soil, which can be supplemented with lunar soil (made into a slurry with water and sloshed around to wear down the super-jagged edges) and start growing your own food up there with redirected sunlight. (There are a number of plants that are workably tolerant of 2 week sunlight cycles, like peas, provided you keep them cold between sunny periods.)


>The convenience of being on a giant rock versus a sitting duck in space can't be understated, either. It makes a lot of things a lot less complicated, especially supplying the base. The deceleration and coupling that ships to the ISS have to go through would be completely negated on the moon - all you have to do is land something relatively close (within a few hundred yards, maybe?) to the base and you're set. It's like threading a needle versus hitting the broad side of a barn.

Less complicated sure, but much more expensive. You need a whole lot more delta-V to go to the moon (and land something with a hope of staying intact) than to LEO. It actually takes less fuel to send supplies to mars (because they can use aerobraking/parachutes to slow down) than to the moon.

>Fuel costs would obviously be greater, but not all that much, and once there is a permanent mobile presence in near space, the fuel cost will really just be relegated to getting from the surface into orbit (which is most of the fuel cost anyway).

Wouldn't it be better to work on that "permanent mobile presence in near space" first?

Low Earth orbit is a pretty good place to be; it's the easiest to get to from Earth, and it's on the way to just about anywhere.


Yeah the sanest option I've heard is throwing some construction robots up (obviously not easy but far from impossible) to dig us a nice hole to live in when people get there, set up a reactor, start finding water, etc.


Construction "waldoes" are well within our capability for a year out. The Japanese have already been experimenting with on-orbit teleoperation with a synthesized lag of one full second. It sucks to work that way, but human beans are amazing, and I think there's many a talented gamer who would love to work in space from the comfort of planet Earth.

http://en.wikipedia.org/wiki/Waldo_(short_story)


Maybe that's why so many places in the US still have shitty internet - to teach the gamers to cope with lag better.


Oh the irony, if the US turned out to be the dominant power in space because of a head-start from hordes of lag tolerant gamers.


>human bean


It's a habit I have of bean cute.


Bean there ... Done that


Shush, you're spilling the...


Ok, well accelerate it very slowly. Don't have people onboard during transit, and instead park it in Earth-Sun L2 where most of the solar radiation would be blocked.

Problems solved?


Earth-Sun L2 where most of the solar radiation would be blocked.

Only it wouldn't, because the Earth's shadow doesn't extend that far out. Earth-Sun L2 is a million miles from Earth; Earth's shadow tapers to a point well before that.


Yup. You would be in the antumbra: http://en.wikipedia.org/wiki/File:Diagram_of_umbra,_penumbra...

Better than nothing I guess? Probably not by much though.


Probably not by much though.

Actually, I was somewhat pessimistic:

Angle subtended by Earth at a million miles: (8 thousand)/(1 million) = 0.008

Angle subtended by Sun at 94 million miles: (864 thousand)/(94 million) = 0.0092

Area of Sun covered by Earth: (0.008 squared)/(0.0092 squared) = 0.76

So about 76 percent of the Sun's visible area would be covered by the Earth. The Sun would be about 1/4 as bright from L2 as it is at noon on Earth. That's still very, very bright, but there is some effect due to the Earth.

Also, it's worth noting that the most dangerous radiation in interplanetary space (solar wind and cosmic rays) is not "shadowed" by the Earth in quite the same way visible light from the Sun is. The Earth's magnetosphere does have a "tail" that extends behind the Earth, but there is radiation inside it.


Hmm. Any idea how much protection being behind the earth like that would provide against solar flares?


Probably not much. Solar flares inject plasma into the magnetosphere, and because of the magnetic fields involved the motion of the plasma particles is not directly away from the Sun; they curve into the space that would otherwise be "shadowed" by the Earth.




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