What would it take for a space mission to dirrectly make a profit?

[Seret]

It's night on earth half the time. A satellite can be dumped into an orbit that permanently has sunlight, so you can gather at least twice the energy in space simply because of that. You also cut down on atmospheric losses and the 0G environment means you can make the solar panels ultra thin without then snapping under their own weight. All those things combined can make for a pretty viable energy source.

Unfortunately the cost of lifting the equipment into orbit is high, while the cost of PV arrays themselves has nosedived. It would be cheaper to simply build a larger array on Earth to offset the reduced amount of sunlight. Space solar power stations just can't compete with Earth based ones. No reason they could beam it to something else in space though.

[Idobox]

Unfortunately the cost of lifting the equipment into orbit is high, while the cost of PV arrays themselves has nosedived. It would be cheaper to simply build a larger array on Earth to offset the reduced amount of sunlight. Space solar power stations just can't compete with Earth based ones. No reason they could beam it to something else in space though.

Hence, you need to build a mine and factory on the moon. The crust contains large amounts of aluminium, iron and silicon. I'm not sure what you need to dope the silicon to make decent solar arrays, but if it's not easy to come by, you might send a few kg of the stuff once in a while. And the main problem with solar arrays on Earth is not price, it's unreliability and lack of good storage solutions. If you convert all your power supply to solar, you better learn how to read in the dark.

The basic idea behind spaced based solar is to beam things back through microwave. People will complain that it gives them space cancer, you will need absurdly large antennas on both sides, and there's probably a way to weaponize it.

[SunJumper]

Also, taking this literally, a space mission is economically viable if it can return material that costs more than the mission itself.

For example, the Apollo program (Rockets only, not counting mission support, ground facilities, etc, things that could be reused, while the Saturn V rockets definitely could not) cost about 14.8 billion. Now, taking sample mass as purely gold, the 380.5kg would be 17,000,000 dollars. If you take the people out and pretend each mission brought back 110.3kg, that is ~1500kg, or 66,900,000. In the latter case, that is a loss of 99.548%.

[falofonos]

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

Any of those in quantity would be worth extracting. Better to keep them in LEO or lunar location to produce toys outside of the gravity money pit though.

[Seret]

Hence, you need to build a mine and factory on the moon.

Unlikely, semiconductor fab is an energy-intensive high-precision process. Setting up a facility of that complexity on the moon would require a lot of pre-existing infrastructure.

[Nuke]

If you find water, you can make LH2/LO2 and sell it to other space operators to refuel once in space. You could also sell moon rocks for novelty.

The moon is not protected by either a magnetic field or an atmosphere, and doesn't have wind or a water cycle, so the top soil accumulates particles from solar wind, like He3. That being said, He3 is worthless as a fusion fuel (more difficult to fuse than D-T or even D-D and still produces neutrons) and present in tiny concentrations only.

i kinda think the p-b11 reaction will be the pinnacle of fusion reactor design, the fuel is abundant on earth and produces no neutrons. but we will be using neutron spewing reactors for decades before we get there.

also have to agree with satellite refueling services. though i have a feeling the propellant wont be lh2/lox (especially lox which likes to boil off over time, less your tanks rupture). satellites usually use hydrazine for station keeping, and ion station keeping thrusters are replacing those rather rapidly. there are also exotic means, like feep, which are perfered on space telescopes for their control resolution, and those run on liquid metals. you will probibly need a wide variety of fuels/propellants to bring to market. and eventually radioactive materials will be desirable to refuel fission powered ships.

[Aghanim]

i kinda think the p-b11 reaction will be the pinnacle of fusion reactor design, the fuel is abundant on earth and produces no neutrons. but we will be using neutron spewing reactors for decades before we get there.

also have to agree with satellite refueling services. though i have a feeling the propellant wont be lh2/lox (especially lox which likes to boil off over time, less your tanks rupture). satellites usually use hydrazine for station keeping, and ion station keeping thrusters are replacing those rather rapidly. there are also exotic means, like feep, which are perfered on space telescopes for their control resolution, and those run on liquid metals. you will probibly need a wide variety of fuels/propellants to bring to market. and eventually radioactive materials will be desirable to refuel fission powered ships.

Unfortunately it is only abundant on earth, I have asked wikipedia ref desk before about availability of boron in asteroids and it is scarce

But seawater have a lot of boron and hydrogen

[Nuke]

i can see p-b11 only being used in terrestrial applications. in space you got to use whatever you can find. aneutronic fusion reactors would be preferable in space, since they reduce maintenance requirements and will likely have a longer operational life. it might also be easier to boost boron to orbit at this point. or we could fall back on he3-he3 reactors, not because of the qualities of the reaction but because we can refuel at the moon. he3 is still pretty rare, so it might just be an initial supply until we can find better fuel sources. p-Li7 might also be an option, lower cross section but larger output than p-b11.