Harvesting gases from planets

[Eagle]

It would need to be outfitted with a fission reactor first.

Maybe, its doable with solar panels, but you will have to increase ISS's available power a little more than fivefold.

The only hard part is getting an engine with a specific impulse greater than ISS's orbital speed(and uses air or an air derivative as reaction mass(Nitrogen?)). Using wikipedia's number of: 7.707 km/s we NEED an ISP greater than that.

Why? Every kilogram collected needs to be accelerated up to ISS's speed. To counter the 7.707 kN force. We counter it by spewing out mass the other end. If our ISP is lower than our orbital speed we spend more than 1 kg in reaction mass.

Lets say we use all Nitrogen collected as reaction mass (~75% by mass). We need an ISP of: 10.2 km/s. If we use 90% of what we collected we only need an ISP of: 8.5 km/s

Now, people need 2.4 g of O2 a minute. Lets say the 10% we keep is all O2 and we have six crew members (2.4*10^-4 kg/s) needed. To sustain this we need to scoop 2.4*10^-3 kg/s from around us.

This means our scoop will give us a drag off: 18.5 N. Using an ISP of 8.5 km/s and 100% efficiency gives us a minimum power requirement of: 158.4 kW. Depending upon the efficiency it may be significantly higher.

ISS produces 33 kW, so you will need some more power(from some source).

But, we don't need to truck in air any more.

Anyone want to calculate how large the scoop would be?

 

[Eagle]

One more thing

If you build it well enough and pipe all of the scooped air through the cabin. The required mass and drag drop a little more than half ~12*10^-3 kg/s & 9.2 N.

The required ISP is approximately equal to your orbital speed (if using cabin air as reaction mass). Dropping minimum power requirements to: 95 kW.

Realistically you'll probably have a low efficiency that brings power requirements to around 300-900 kW but its all very doable.

 

[Lunar Pilot]

?

Exactly how does it get this ''air'', considering its orbiting at an altitude of about 220 miles? That would be far above the atmosphere. Besides, why would they put a station that had an orbit below the atmosphere? It crashing almost instantly.

 

[joiz]

the ISS is still in the atmosphere: every so often they have to rocket it up a bit higher so it doesn't come crashing down like Mir and Skylab did. a big thin-as-foil scoop could get it a load of air to keep it going forwards and get the astronauts free air and water (although it would be a huge scoop and could hinder shuttle and Soyuz rondez-vous not to mention a fission reactor that the Greenpeace fanatics would try to stop) an easier way to keep the ISS up and much lighter would be an ion engine...

 

[Lunar Pilot]

''air scoop

Now that you explain it, it sounds a lot better than the Space Shuttle speeding it up.

 

[Hartmann]

Harvest gas from venus using spacecrafts with solar sails and drop it to mars, raising with this the atmosphere pressure ...

 

[Lunar Pilot]

Mars

Ah, Hartmman, I'm afraid that even if we did do that, it would be completely worthless. Since Mars has no global magnetic field, the solar wind would erode the atmosphere that we put there, of course, this would take thousands of years, but since, as stated earlier, there is no Martian magnetic field, Mars is unhabitable, so it would be a waste of time and energy.

 

[Eagle]

Harvest gas from venus using spacecrafts with solar sails and drop it to mars, raising with this the atmosphere pressure ...

Could work. The main problem is that to make an appreciable difference you will need to move millions or trillions of tons of material. The second problem is balancing the atmospheric drag of the solar sail itself.

Several ways of doing it. The multi-ship solution (probably most efficient) is to keep a harvester in Venus orbit. Probably some eccentricity where it dips down to skim some atmosphere, then shoots up where there is less air resistance and it can recover its orbital speed. Harvesting the gas will be painfully slow.

The second ship would then take the skimmed gases from Venus to Mars orbit. The gas could be dropped on a collision course, while the sail prepares for another rendezvous with Venus. I don't know what the requirements for the dropped container would be, maybe it could be liquefied and enough would survive.

Teraforming is TOUGH and the scale will need to be HUGE just to beat atmospheric losses. It would probably be easier to crash comets onto Mars.

 

[willy88]

Ah, Hartmman, I'm afraid that even if we did do that, it would be completely worthless. Since Mars has no global magnetic field, the solar wind would erode the atmosphere that we put there, of course, this would take thousands of years, but since, as stated earlier, there is no Martian magnetic field, Mars is unhabitable, so it would be a waste of time and energy.

What about some sort of artificial magnetic field? I'm sure Dr. Evil would be interested, for some reason...

 

[Lunar Pilot]

Artificial Magnetic Field

Well, that's a very good idea, but we just can't make a field that big, the only way we could do that would be to restart the Martian core, but since it's frozen, we'd have to melt it. Besides, we don't even know exactly how the Earth produces it's magnetic field, just theories about electrical and magnetic pulses and iron in the outer core.

 

[ar81]

How about pumping the gas out of the planet? :rofl::lol:

 

[AstroCam]

Nice water bomber butt pic

Anyway, does anyone read Schlock Mercenary? A fusion rocket 'candle' burning at both ends (Either one colossal one, or squillions of little ones), lowered into a gas giants atmosphere could move the planet. The atmosphere is sucked in through the middle of the candle, compressed, and feed through fusion reactors out nozzles on either end - as there is no solid surface on the gas giant, the rocket must support itself in the atmosphere, hence the other nozzle pointing DOWN.

That said, when we finally DO invent neutronium annhilation reactors and teraports, i think terraforming a planet or acuiring fuel in the outter solar system wouldn't be a problem....