Well, you assume that whoever made the MS06-049 patch actually took the time to understand the code he was patching and/or contacted the person who origionally wrote the code in question.
There's two possible reasons behind this particular lawsuit. One is because the SCO execs want to go after IBM for extortion. The other reason is because Microsoft is trying to go after Linux.
If the second is true, any actions from here may be oriented towards preventing Microsoft from being revealed as the Man Behind The Curtain, rather than winning.
Well, that, and it probably wasn't given the detail work necessary to have it examined at such large magnification.
I couldn't deal with the only IMAX blowup I've ever seen because the animator's lines were swimming in space instead of clean-looking like they were in the 35mm distribution print.
If you want an IMAX film, you need to shoot it as such.
No, as you launch more missions, there is necessarily a shorter gap between them.
Plus, you forget about pad time vs. stacking time. If we are using LC-39, there are three mobile launch platforms, two pads, and four bays in the VAB without doing major modifications or construction. Without building extra pads in LC-39 (which, if NASA does manage to actually launch the new launch vehicles often, is almost required, given that there are two different types of launcher), that still lets you begin a launch campaign with 3 fully stacked vehicles and room to start stacking a fourth after the first launch.
And there's always building a fourth mobile launch platform and/or using LC 34 for one of the launches, giving five launches in quick succession.
With the CLV as-is, the same upmass could as the heavy lift booster be carried in about four flights. With an upraded "universal" booster, you could easily do it with three launches.
Remember how short the time was between Gemini 6 and 7? That was with them both launching from the same pad.
Also, if you boot 'em up to a higher parking orbit, atmospheric drag decreases.
Fully autonomous docking is not necessary. The lightspeed delay to orbit is sufficently small that some people on the ground can bang them together just fine.
Sure there's not much left on the market, although that's mostly because of the problems that NASA has already created for itself in combination with the defense biz.
Also, there's not even much incentive for the teams to deliver the actual cheapest system. They just have to write the best proposal. Were they to have flown demonstrators of the two designs, NASA wouldn't need to start a bidding and design process all over again to switch systems, they'd just need to give the other team a year or two of lead time to dust off the design.
Man-rating is a myth. NASA has traditionally invented arbitrary standards to justify their own empire-building that the commercial competition just happens to not be able to meet... and then giving their own projects exemptions to the standards once they are partway through and are almost out of money.
Remember, none of the parts of the SdLVs are currently man-rated. The SRBs have an extra segment, so they will need to be certified again because they've never flown in that configuration. The ET wasn't designed to have thrust on that vector, so you can't just duct-tape engines to the bottom of it and re-use it. The EDS and CLV second stage are completely new stages.
Oh, and they'll need to build at least one more complete launchpad at KSC.
There were plenty of proposals for clustering EELV first stages together. Just because the Atlas V only has launched with one CCB and the Delva IV has launched with three CBCs doesn't mean that's all they can handle.
Oh, and there's not any need for a heavy lift booster anyway. It's going to be far cheaper per pound to launch more missions with less payload per mission and means that you could have three singly-redundant EDS modules instead of one tripply redundant EDS module.
NASA is going through the trouble of building all of this new infrastructure primarily because if any of the shuttle-related factories are closed down, congresscritters will be unhappy and NASA managers may have nothing to do, not because it is the cheapest, best, or safest way to go.
The need for a large booster is based around flawed assumptions.
The heavy lift booster flies twice a year, the light booster flies maybe 6 times a year. It would be far cheaper to fly a single medium booster 12 flights a year. Same, if not more upmass will be flown. Remember, the more of the same thing you build, the cheaper it gets, because you can use more economical manufacturing techniques.
Also, think about the difference between sending two or three smaller earth departure stages into a parking orbit instead of sending a single larger earth departure stage. The larger departure stage MUST work, so you'll make it doubly or tripply redundant. The smaller stages have lowered requirements for working because there's two or three of them, so you don't need to add as much redundancy, therefore the individual stages contain more fuel and less redundant hardware. Both the Americans and the Russians have ample experience bumping two modules into each other at the correct spot to build a larger module... that's not a huge problem at all.
DART was not doing in-space docking. It was doing autonomous in-space inspection and maintenence, which is much much harder, especially because the goal was to not need to design the target to be maintained.
There's a huge difference between bumping two modules together at a socket-recepticle connector and manuvering around a vehicle autonomously.
The US has been bumping socket-recepticle connectors together since the days of Gemini and the Russians have been mostly-automatically bumping androgynous connectors together since the days of Salyut.
I'm more thinking about the Elektron module's endless troubles, which is really the part that's been getting in the way and acting up so far.
Oh, and there's also the whole reaction wheel thing, that's bad on the US side.
Much of the hardware on the US side that would have been nice to use long-term in space so that future designs could rely on it hasn't been launched yet (like the US version of Elektron) or has been canceled altogther (like the US Propulsion module).
Really, the problem I see isn't that the Russian hardware is any more or less reliable than the US hardware (Remember, the Russians have a better track record with the Soyuz not being grounded than the US has with the shuttle not being grounded) but that unless NASA wants to go through the trouble of dealing with the Russian space program again, it doesn't help if the Russian hardware works just fine because that doesn't give the NASA-specified hardware suppliers much space experience.
Sure, a sunshade cover would be great. Were NASA to not have been asleep at the wheel, an astronaut would have climbed into their zero-prebreathe suit and exited the minimal-atmospheric-loss airlock, and banged on it with a NASA Standard Hammer. But, given that NASA hasn't spend much money on improved spacesuits since the Apollo days, EVAs are scarry things and require much preparations.
There aren't any alternatives funded for the CEV. It's about as competitive as the shuttle's procurement was. NASA was going to make the two leading teams do a fly-off, but that was removed from the plan. So, one CEV booster that's intended to last us all the way to the Mars shot, and no alternatives.
We don't need two new boosters. We don't even need two boosters at all. It would have been far cheaper to just source either Delta or Atlas EELV stages. (and leave open the option for SpaceX to sell a Falcon 9 when they get that one ready) Or, if they had wanted to build a new booster that bad, to make something that was somewhat bigger than the CEV's booster stage and then distribute the pieces of any lunar exploration missions into a series of launches. But, instead, NASA builds *two* new boosters at the same time and gets to deal with two sets of development problems with increasing amounts of divergence between the two designs.
That NASA still cannot just source lift capability on the open market demonstrates just how they haven't learned their lessons.
An effective prototype would be able to survive for several years between resupply missions.
Remember, the only "on orbit repair" work that's been done is swapping out parts. If the crew was able to take soldering iron and diagonal cutters to the hardware and fix things, or actually put on a spacesuit and check out why a thruster wasn't firing properly, then it would be a realistic prototype for a Mars mission.
The CEV's going to be just as much of a clusterfuck as the shuttle. All of the same contractors are going to do to it the same thing they managed to do with the shuttle.
Look at the proposal. The SRB first stage on the CEV's booster.... so that Thikol doesn't complain to their congresscritter. The cargo vehicle with the external tank so that you don't lose that factory. No effort to make the CEV work on anybody else's launcher, like the EELV Atlas and Deltas or maybe let SpaceX try to undercut things. The CEV proposals being geared towards the big aerospace contractors. Etc.
Nope, the only thing NASA is doing right is the COTS program. And you can bet that if it starts to look really good, it'll get canned, sidelined, or otherwise disrupted so as to not end up working out.
Well, the storage room wouldn't be so expensive if they were to use some modules like the TransHab module..... oops, canceled that.
I was very excited about the possibilities of the Centerfuge Accomidation Module. Finally they could put up some rodents or fish or other small-enough-to-work-on-the-centerfuge research animals and make them run through the entire reproductive cycle in space repeatedly at different levels of gravity, so if a few Blessed Events accidentally happen some day up there, they'll know what to do..... oops, but that got canned to.
It would be useful for on-orbit checkout of large spacecraft.... but the 51 degree inclanation orbit is going to cost you enough in payload and reduced opportunities for launch that there's no point... you might as well launch something sized like the FGB into the right orbit and you'll come out ahead.
It would be great for researching viruses and such because you can crystalize proteins in space easier than on the ground.... except that between the 1980s when they were going on about it and now, they instead developed improved analytical machines that don't require the sort of perfect large crystals that space is good for.
Oh! Right! We can test out space systems that would be useful for the real missions later on. Except that the station STILL relies on a bunch of Russian hardware that we already know is a smidge clunky.
The station makes perfect sense when you realize that it's a bunch of repackaged hardware built around assumptions from the 70s that we knew to be untrue around 85. The problem is that they didn't take a big step backwards at any point between 1985 and 2000 and really reassess things.
For example, the only time that the option of launching some of the American modules on an expendable booster was considered, they wanted to make the Shuttle-C, not just buy a quiver of Atlas or Titan rockets.
Get a flatbed scanner with a negative holder, find the negatives, and scan those.
It will look much better than the faded colors of an old print.
You can only fit 2-3 prints on a flatbed at the same time, but you can usually fit at least two strips of negatives -- between 8 and 12 pictures -- at the same time on a flatbed.
*However* no matter how you dice it, it'll take a long time to properly go through them. But then again, going through old pictures is kinda fun.:)
When you have alt-tab'd out and have something else covering up the bud lite girls, you are still listening and therefore having your subconscious subverted.
As far as I'm concerned, there's no real reason why the stations need to be screwed over. Just make an approximate guess as to your geographical location via your IP address and splice in the local used car dealership threatening to club a baby seal if you don't buy a car from him.
I'm almost picturing some sort of combined heater/spool such that you could generate a blob of hot solder in zero-G, apply it to the board, and then start the workpiece rotating to "suck" the solder into the right position.
However, the atmosphere of mars is such that the insulation methods used for the Shuttle and Apollo EV suits won't work and they'll have to use heavier insulation.
So, to make a good moonsuit, you have to fix the seals.
To make a good mars suit, you have to fix the seals, make it lighter weight, fix the insulation, etc.
Re:Less challenges on the moon?
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US Plans Lunar Motel
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· Score: 5, Insightful
Ah, but convection doesn't work, so you increase the possibility of any fluxes not properly floating to the top. You also have to wory about the flux evaporating and causing the solder to be propelled away from the workpiece. Also, some soldering and welding processes are designed to work inside the atmosphere, others are designed to work outside of the atmosphere.
But, no, nothing on the ISS is being welded in space. It is sent up in large chunks and is bolted together, often times with motorized screws so that the astronauts just have to manuver the pieces towards each other and then command the berthing mechanism to grip. They have been doing some limited soldering experiments in the ISS, but never as repair work, just as tests for eventually doing repair work.
The biggest problem is that a spacewalk takes too much effort to set up. You have to plan it out. You have to pre-breathe oxygen. You have to replace all of the relevant consumables. The people doing them are scientists, not bridge workers.
You can only get so far with merely bolting stuff together. Eventually, you need to start doing fabrication work. Sure, it's easier to send up 1 ton of easy-to-fab raw materials, but it's even easier to grab a 100 ton iron asteroid and not bother calling back to Earth at all.:) Remember that some of the iron asteroids are basicly steel with sufficent levels of purity that you could slice 'em up with a cutter and use them as building materials with nay but a quick metalurgical assay.
Some things will be much much easier in space. Ovens for example. A nice parabolic reflector to focus the sun's heat on a lump of metal can be made out of aluminised mylar and (titanium) chickenwire. You can use a refractory blowpipe to blow a bubble out of the lump once it's melted. Taking this to a logical extension, I could see large structures being manufactured using something akin to a glassblower's lathe.
But the problem is, on both the how-do-we-repair-things-and-build-new-things-in-sp ace front and the how-much-gravity-do-we-need-to-not-die-young-in-sp ace front, we've done... ehrm... almost nothing since the 60s.
Re:Less challenges on the moon?
on
US Plans Lunar Motel
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· Score: 5, Informative
Take a welding class sometime. There is much much much more to welding than the standard oxy-acetelyne torch.
Oxygen is not required. There are certain high-strength welding processes that even require a vacuum to work.
They already need to deal with the problem of oxygen, hydrogen, and nitrogen getting into the welds, which is why stick welders have a thick coating of flux on the rods and MIG and TIG welders cover the weldment with a variety of inert or mostly-inert gasses.
If you build the spacecraft on the moon and only send up fuel, you may come out ahead.
If you build a mass driver on the moon for launch, you come out ahead.
If you were to use nuclear propulsion, the amount of fuel required might be sufficently small to outweigh the disadvantages. Remember, you can use a nuclear powered craft to escape the gravity well, it would just cause cancer in a lot of folks if you ever tried it on Earth.
But... ehrm... yeah, it's probably still better to assemble and launch from L4 or L5.
Re:Less challenges on the moon?
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US Plans Lunar Motel
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· Score: 4, Interesting
Well, it depends on your point of view.
If you suffer from a power/oxygen/water/etc. system failure, all you need is a few weeks supplies in the shelter on the moon. Wheras, you need to ensure that at all points in time, you've got 2 years worth of shelter supplies on Mars.
Also, the lowered gravity and nearly-nonexistent atmosphere means that a moonsuit from the 60s still works out well enough.
Also, given that you have only 3 days outside of the earth's magnetosphere to get there, you'll accumulate a lot less radiation on the way there than you would going to Mars.
Of course, that also would require piling lunar soil and rocks on top of whatever the lunar base ends up being made out of to provide sufficent mass.
But, still... Because of all of these things, it's easier to get a toehold sooner on the Moon.
The problem is that NASA has yet to grasp the idea of a fully independent spacecraft. It works out reasonably well to have astronauts swap out complete assemblies in LEO, where you can send up and down the stuff, if you are talking about going to Mars or Io or Titan or even near-earth-asteroids, you are going to be too far to pull stunts like that. We barely know how to weld and solder in space and nobody's ever tried to make a set of machine shop tools for space like lathes and mills. The moon would be a great place to research such things, but that also depends on NASA breaking with tradition and not blowing a good chance yet again.
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Many of the Epson Flatbeds will take 4x5s just fine.
Well, you assume that whoever made the MS06-049 patch actually took the time to understand the code he was patching and/or contacted the person who origionally wrote the code in question.
pffft.
You ain't seen a beautiful show till you see a RP-1/LOX booster launch. That's a good show. RS-68's are better, but F-1's still rule.
Well, here's the big question...
There's two possible reasons behind this particular lawsuit. One is because the SCO execs want to go after IBM for extortion. The other reason is because Microsoft is trying to go after Linux.
If the second is true, any actions from here may be oriented towards preventing Microsoft from being revealed as the Man Behind The Curtain, rather than winning.
You forget one thing.
These are static images. A static image can be printed huge and the viewer can concentrate on small portions of the image by getting up close to it.
Well, that, and it probably wasn't given the detail work necessary to have it examined at such large magnification.
I couldn't deal with the only IMAX blowup I've ever seen because the animator's lines were swimming in space instead of clean-looking like they were in the 35mm distribution print.
If you want an IMAX film, you need to shoot it as such.
No, as you launch more missions, there is necessarily a shorter gap between them.
Plus, you forget about pad time vs. stacking time. If we are using LC-39, there are three mobile launch platforms, two pads, and four bays in the VAB without doing major modifications or construction. Without building extra pads in LC-39 (which, if NASA does manage to actually launch the new launch vehicles often, is almost required, given that there are two different types of launcher), that still lets you begin a launch campaign with 3 fully stacked vehicles and room to start stacking a fourth after the first launch.
And there's always building a fourth mobile launch platform and/or using LC 34 for one of the launches, giving five launches in quick succession.
With the CLV as-is, the same upmass could as the heavy lift booster be carried in about four flights. With an upraded "universal" booster, you could easily do it with three launches.
Remember how short the time was between Gemini 6 and 7? That was with them both launching from the same pad.
Also, if you boot 'em up to a higher parking orbit, atmospheric drag decreases.
So?
Fully autonomous docking is not necessary. The lightspeed delay to orbit is sufficently small that some people on the ground can bang them together just fine.
Sure there's not much left on the market, although that's mostly because of the problems that NASA has already created for itself in combination with the defense biz.
Also, there's not even much incentive for the teams to deliver the actual cheapest system. They just have to write the best proposal. Were they to have flown demonstrators of the two designs, NASA wouldn't need to start a bidding and design process all over again to switch systems, they'd just need to give the other team a year or two of lead time to dust off the design.
Man-rating is a myth. NASA has traditionally invented arbitrary standards to justify their own empire-building that the commercial competition just happens to not be able to meet... and then giving their own projects exemptions to the standards once they are partway through and are almost out of money.
Remember, none of the parts of the SdLVs are currently man-rated. The SRBs have an extra segment, so they will need to be certified again because they've never flown in that configuration. The ET wasn't designed to have thrust on that vector, so you can't just duct-tape engines to the bottom of it and re-use it. The EDS and CLV second stage are completely new stages.
Oh, and they'll need to build at least one more complete launchpad at KSC.
There were plenty of proposals for clustering EELV first stages together. Just because the Atlas V only has launched with one CCB and the Delva IV has launched with three CBCs doesn't mean that's all they can handle.
Oh, and there's not any need for a heavy lift booster anyway. It's going to be far cheaper per pound to launch more missions with less payload per mission and means that you could have three singly-redundant EDS modules instead of one tripply redundant EDS module.
NASA is going through the trouble of building all of this new infrastructure primarily because if any of the shuttle-related factories are closed down, congresscritters will be unhappy and NASA managers may have nothing to do, not because it is the cheapest, best, or safest way to go.
The need for a large booster is based around flawed assumptions.
The heavy lift booster flies twice a year, the light booster flies maybe 6 times a year. It would be far cheaper to fly a single medium booster 12 flights a year. Same, if not more upmass will be flown. Remember, the more of the same thing you build, the cheaper it gets, because you can use more economical manufacturing techniques.
Also, think about the difference between sending two or three smaller earth departure stages into a parking orbit instead of sending a single larger earth departure stage. The larger departure stage MUST work, so you'll make it doubly or tripply redundant. The smaller stages have lowered requirements for working because there's two or three of them, so you don't need to add as much redundancy, therefore the individual stages contain more fuel and less redundant hardware. Both the Americans and the Russians have ample experience bumping two modules into each other at the correct spot to build a larger module... that's not a huge problem at all.
DART was not doing in-space docking. It was doing autonomous in-space inspection and maintenence, which is much much harder, especially because the goal was to not need to design the target to be maintained.
There's a huge difference between bumping two modules together at a socket-recepticle connector and manuvering around a vehicle autonomously.
The US has been bumping socket-recepticle connectors together since the days of Gemini and the Russians have been mostly-automatically bumping androgynous connectors together since the days of Salyut.
I'm more thinking about the Elektron module's endless troubles, which is really the part that's been getting in the way and acting up so far.
Oh, and there's also the whole reaction wheel thing, that's bad on the US side.
Much of the hardware on the US side that would have been nice to use long-term in space so that future designs could rely on it hasn't been launched yet (like the US version of Elektron) or has been canceled altogther (like the US Propulsion module).
Really, the problem I see isn't that the Russian hardware is any more or less reliable than the US hardware (Remember, the Russians have a better track record with the Soyuz not being grounded than the US has with the shuttle not being grounded) but that unless NASA wants to go through the trouble of dealing with the Russian space program again, it doesn't help if the Russian hardware works just fine because that doesn't give the NASA-specified hardware suppliers much space experience.
Sure, a sunshade cover would be great. Were NASA to not have been asleep at the wheel, an astronaut would have climbed into their zero-prebreathe suit and exited the minimal-atmospheric-loss airlock, and banged on it with a NASA Standard Hammer. But, given that NASA hasn't spend much money on improved spacesuits since the Apollo days, EVAs are scarry things and require much preparations.
Um.
There aren't any alternatives funded for the CEV. It's about as competitive as the shuttle's procurement was. NASA was going to make the two leading teams do a fly-off, but that was removed from the plan. So, one CEV booster that's intended to last us all the way to the Mars shot, and no alternatives.
We don't need two new boosters. We don't even need two boosters at all. It would have been far cheaper to just source either Delta or Atlas EELV stages. (and leave open the option for SpaceX to sell a Falcon 9 when they get that one ready) Or, if they had wanted to build a new booster that bad, to make something that was somewhat bigger than the CEV's booster stage and then distribute the pieces of any lunar exploration missions into a series of launches. But, instead, NASA builds *two* new boosters at the same time and gets to deal with two sets of development problems with increasing amounts of divergence between the two designs.
That NASA still cannot just source lift capability on the open market demonstrates just how they haven't learned their lessons.
Not really.
An effective prototype would be able to survive for several years between resupply missions.
Remember, the only "on orbit repair" work that's been done is swapping out parts. If the crew was able to take soldering iron and diagonal cutters to the hardware and fix things, or actually put on a spacesuit and check out why a thruster wasn't firing properly, then it would be a realistic prototype for a Mars mission.
Um.
The CEV's going to be just as much of a clusterfuck as the shuttle. All of the same contractors are going to do to it the same thing they managed to do with the shuttle.
Look at the proposal. The SRB first stage on the CEV's booster.... so that Thikol doesn't complain to their congresscritter. The cargo vehicle with the external tank so that you don't lose that factory. No effort to make the CEV work on anybody else's launcher, like the EELV Atlas and Deltas or maybe let SpaceX try to undercut things. The CEV proposals being geared towards the big aerospace contractors. Etc.
Nope, the only thing NASA is doing right is the COTS program. And you can bet that if it starts to look really good, it'll get canned, sidelined, or otherwise disrupted so as to not end up working out.
Well, the storage room wouldn't be so expensive if they were to use some modules like the TransHab module..... oops, canceled that.
I was very excited about the possibilities of the Centerfuge Accomidation Module. Finally they could put up some rodents or fish or other small-enough-to-work-on-the-centerfuge research animals and make them run through the entire reproductive cycle in space repeatedly at different levels of gravity, so if a few Blessed Events accidentally happen some day up there, they'll know what to do..... oops, but that got canned to.
It would be useful for on-orbit checkout of large spacecraft.... but the 51 degree inclanation orbit is going to cost you enough in payload and reduced opportunities for launch that there's no point... you might as well launch something sized like the FGB into the right orbit and you'll come out ahead.
It would be great for researching viruses and such because you can crystalize proteins in space easier than on the ground.... except that between the 1980s when they were going on about it and now, they instead developed improved analytical machines that don't require the sort of perfect large crystals that space is good for.
Oh! Right! We can test out space systems that would be useful for the real missions later on. Except that the station STILL relies on a bunch of Russian hardware that we already know is a smidge clunky.
The station makes perfect sense when you realize that it's a bunch of repackaged hardware built around assumptions from the 70s that we knew to be untrue around 85. The problem is that they didn't take a big step backwards at any point between 1985 and 2000 and really reassess things.
For example, the only time that the option of launching some of the American modules on an expendable booster was considered, they wanted to make the Shuttle-C, not just buy a quiver of Atlas or Titan rockets.
Get a flatbed scanner with a negative holder, find the negatives, and scan those.
:)
It will look much better than the faded colors of an old print.
You can only fit 2-3 prints on a flatbed at the same time, but you can usually fit at least two strips of negatives -- between 8 and 12 pictures -- at the same time on a flatbed.
*However* no matter how you dice it, it'll take a long time to properly go through them. But then again, going through old pictures is kinda fun.
Consider this, however....
When you have alt-tab'd out and have something else covering up the bud lite girls, you are still listening and therefore having your subconscious subverted.
As far as I'm concerned, there's no real reason why the stations need to be screwed over. Just make an approximate guess as to your geographical location via your IP address and splice in the local used car dealership threatening to club a baby seal if you don't buy a car from him.
Oh, that's an interesting idea.
I'm almost picturing some sort of combined heater/spool such that you could generate a blob of hot solder in zero-G, apply it to the board, and then start the workpiece rotating to "suck" the solder into the right position.
Yeah, they completely forgot about the Apple ///, which was the first true failure.
:)
At least the Lisa stuff got reused as bits of the Mac.
Yes.
However, the atmosphere of mars is such that the insulation methods used for the Shuttle and Apollo EV suits won't work and they'll have to use heavier insulation.
So, to make a good moonsuit, you have to fix the seals.
To make a good mars suit, you have to fix the seals, make it lighter weight, fix the insulation, etc.
Ah, but convection doesn't work, so you increase the possibility of any fluxes not properly floating to the top. You also have to wory about the flux evaporating and causing the solder to be propelled away from the workpiece. Also, some soldering and welding processes are designed to work inside the atmosphere, others are designed to work outside of the atmosphere.
:) Remember that some of the iron asteroids are basicly steel with sufficent levels of purity that you could slice 'em up with a cutter and use them as building materials with nay but a quick metalurgical assay.
p ace front and the how-much-gravity-do-we-need-to-not-die-young-in-sp ace front, we've done... ehrm... almost nothing since the 60s.
But, no, nothing on the ISS is being welded in space. It is sent up in large chunks and is bolted together, often times with motorized screws so that the astronauts just have to manuver the pieces towards each other and then command the berthing mechanism to grip. They have been doing some limited soldering experiments in the ISS, but never as repair work, just as tests for eventually doing repair work.
The biggest problem is that a spacewalk takes too much effort to set up. You have to plan it out. You have to pre-breathe oxygen. You have to replace all of the relevant consumables. The people doing them are scientists, not bridge workers.
You can only get so far with merely bolting stuff together. Eventually, you need to start doing fabrication work. Sure, it's easier to send up 1 ton of easy-to-fab raw materials, but it's even easier to grab a 100 ton iron asteroid and not bother calling back to Earth at all.
Some things will be much much easier in space. Ovens for example. A nice parabolic reflector to focus the sun's heat on a lump of metal can be made out of aluminised mylar and (titanium) chickenwire. You can use a refractory blowpipe to blow a bubble out of the lump once it's melted. Taking this to a logical extension, I could see large structures being manufactured using something akin to a glassblower's lathe.
But the problem is, on both the how-do-we-repair-things-and-build-new-things-in-s
Take a welding class sometime. There is much much much more to welding than the standard oxy-acetelyne torch.
:)
Oxygen is not required. There are certain high-strength welding processes that even require a vacuum to work.
They already need to deal with the problem of oxygen, hydrogen, and nitrogen getting into the welds, which is why stick welders have a thick coating of flux on the rods and MIG and TIG welders cover the weldment with a variety of inert or mostly-inert gasses.
There are other problems, of course.
Not necessarily.
If you build the spacecraft on the moon and only send up fuel, you may come out ahead.
If you build a mass driver on the moon for launch, you come out ahead.
If you were to use nuclear propulsion, the amount of fuel required might be sufficently small to outweigh the disadvantages. Remember, you can use a nuclear powered craft to escape the gravity well, it would just cause cancer in a lot of folks if you ever tried it on Earth.
But... ehrm... yeah, it's probably still better to assemble and launch from L4 or L5.
Well, it depends on your point of view.
If you suffer from a power/oxygen/water/etc. system failure, all you need is a few weeks supplies in the shelter on the moon. Wheras, you need to ensure that at all points in time, you've got 2 years worth of shelter supplies on Mars.
Also, the lowered gravity and nearly-nonexistent atmosphere means that a moonsuit from the 60s still works out well enough.
Also, given that you have only 3 days outside of the earth's magnetosphere to get there, you'll accumulate a lot less radiation on the way there than you would going to Mars.
Of course, that also would require piling lunar soil and rocks on top of whatever the lunar base ends up being made out of to provide sufficent mass.
But, still... Because of all of these things, it's easier to get a toehold sooner on the Moon.
The problem is that NASA has yet to grasp the idea of a fully independent spacecraft. It works out reasonably well to have astronauts swap out complete assemblies in LEO, where you can send up and down the stuff, if you are talking about going to Mars or Io or Titan or even near-earth-asteroids, you are going to be too far to pull stunts like that. We barely know how to weld and solder in space and nobody's ever tried to make a set of machine shop tools for space like lathes and mills. The moon would be a great place to research such things, but that also depends on NASA breaking with tradition and not blowing a good chance yet again.