Colonization Order: Moon , then Mars, or direct to Mars

[CultureCitizen]

Apparently, SpaceX is planning missions directly to Mars.
While our moon seems a barren place there are a handful of elements that can be mined:
- Oxygen - used as an oxidant for regular rockets
- Iron - Can be used to produce steel
- Aluminum - Can be used to produce light equipment.

The moon has the advantage of being close, so it is relatively easy to set an industrial base using robots that can be remotely operated and has the lowest delta-v to several points: low earth orbit, the geostationary orbit, and Lagrange points.
Since gravity is lower, the equipment can be put into orbit using a kinetic catapult or a railgun.

On the downside, we have to find a way to deal with regolith that is extremely destructive and find spots that are not exposed to the moon's extreme temperatures ( polar craters are good candidates).

In spite of all the disadvantages setting a robotic base in the Moon should come before trying a manned expedition

 

[Wayne Mack]

While I favor the idea of robotic exploration over manned exploration, I don't see the economic viability of an off-planet mining operation. Assuming that the ore is to be returned to Earth, then there needs to be a constant stream of rockets and fuel. I also suspect that the ore would likely be smelted before shipping to reduce bulk and weight, and that would add another fuel need.

 

[Swank]

While I favor the idea of robotic exploration over manned exploration, I don't see the economic viability of an off-planet mining operation. Assuming that the ore is to be returned to Earth, then there needs to be a constant stream of rockets and fuel. I also suspect that the ore would likely be smelted before shipping to reduce bulk and weight, and that would add another fuel need.

Why would the ore be returned to earth, and why would that take any fuel from the airless moon?


I don't understand the interest in living on Mars. It is not a particularly good place for that. The moon is easy - it already has caves and is nearby. Mine the moon and make rotating habitats with perfect environments for earth life.

 

[CultureCitizen]

While I favor the idea of robotic exploration over manned exploration, I don't see the economic viability of an off-planet mining operation. Assuming that the ore is to be returned to Earth, then there needs to be a constant stream of rockets and fuel. I also suspect that the ore would likely be smelted before shipping to reduce bulk and weight, and that would add another fuel need.

You can just launch a package ( or a module ) to lunar orbit , then a spaceship can pick up the package ( parts, modules, or oxygen) from there.
No fuel is needed as long as you have electricity; you can use something like the spin launcher to put them into the moon's orbit.
It would be a stepping stone to explore other parts of the solar system.

 

[Wayne Mack]

Why would the ore be returned to earth, and why would that take any fuel from the airless moon?

Returning the ore to Earth was the presumption in the original post.

 

[Wayne Mack]

You can just launch a package ( or a module ) to lunar orbit , then a spaceship can pick up the package ( parts, modules, or oxygen) from there.
No fuel is needed as long as you have electricity; you can use something like the spin launcher to put them into the moon's orbit.
It would be a stepping stone to explore other parts of the solar system.

How would electricity for the spin launcher be generated? How large a solar array would be needed to power it? What of the fuel needs for the spaceships that come to collect the ore, either in Lunar orbit or near Earth orbit? Most the fuel consumption for the spaceship would be in escaping Earth. It becomes even greater when one presumes a controlled reentry.

 

[CultureCitizen]

How would electricity for the spin launcher be generated? How large a solar array would be needed to power it? What of the fuel needs for the spaceships that come to collect the ore, either in Lunar orbit or near Earth orbit? Most the fuel consumption for the spaceship would be in escaping Earth. It becomes even greater when one presumes a controlled reentry.

It would have to be a large array of panels or... a nuclear reactor, a small one.
The ships that collect the ore and oxigen would still need fuel .
Now, imagine you want to ship that ore to mars. The ship could cycle between mars and earth without having to spend fuel going deep into Earth's gravity well ( or launching the ship from Earth).

 

[Wayne Mack]

Now, imagine you want to ship that ore to mars. The ship could cycle between mars and earth without having to spend fuel going deep into Earth's gravity well ( or launching the ship from Earth).

I am afraid that I am having a hard time picturing an orbit between Earth and Mars. The other question is, what is the purpose for the mined ore if it never is brought to the Earth's surface? Unless one adds a whole off-Earth infrastructure to refine and use the mined ore, there doesn't seem to be a reason for the mining. If one adds in a space station as being the final destination for the refined ores, then the Moon becomes most plausible due to having the space station near Earth and having a smaller gravity well to escape. I also suspect that it would likely be more efficient to refine the ore on surface rather than having to lift a lot of waste rock into space for refinement.

 

[Venusian Broon]

While I favor the idea of robotic exploration over manned exploration, I don't see the economic viability of an off-planet mining operation. Assuming that the ore is to be returned to Earth, then there needs to be a constant stream of rockets and fuel. I also suspect that the ore would likely be smelted before shipping to reduce bulk and weight, and that would add another fuel need.

I have seen figures....but can't find them again....but I think asteroid mining is, on paper, a cheaper option than any mining in large gravity wells, such as the moon. And definitely Mars. (although you will, of course be needed to mine and exploit materials in both cases to make any sort of permanent base, robotic or biological, unless we make some sort of god-like improvement in the economics and power of our space travel technology)

However there is still a long way to go before we can really say how viable even the asteroid approach really is.

I think I would prefer such technology rather than moon mining however, because, say you want to build infrastructure in another part of the solar system, like Jupiter or Mercury, if you could build tech in situ using a random asteroid (either exactly where you want to set up a base, or perhaps propel a suitable asteroid that is reasonably close by) then you don't have to go to the hassle/energy/extra cost of constructing everything on/near Earth/Moon and then flying all that weight over to the spot you want.

On the other hand, from a perspective of science, the dark side of the moon would be the ideal place to put loads of robotic observatories, of all sorts.

 

[Swank]

Returning the ore to Earth was the presumption in the original post.

I missed that being mentioned. The most valuable use of moon materials would be anything you want in orbit because of the high cost of leaving the earth, making orbital power stations or habitats expensive.

And getting it back to earth only requires free electricity and a heat shield for reentry.

 

[Swank]

Lunar aluminum and oxygen are fuel.

Solar on the moon is very efficient.

 

[AllanR]

I am afraid that I am having a hard time picturing an orbit between Earth and Mars.

Mars cycler - Wikipedia

en.wikipedia.org

 

[CultureCitizen]

I am afraid that I am having a hard time picturing an orbit between Earth and Mars. The other question is, what is the purpose for the mined ore if it never is brought to the Earth's surface? Unless one adds a whole off-Earth infrastructure to refine and use the mined ore, there doesn't seem to be a reason for the mining. If one adds in a space station as being the final destination for the refined ores, then the Moon becomes most plausible due to having the space station near Earth and having a smaller gravity well to escape. I also suspect that it would likely be more efficient to refine the ore on surface rather than having to lift a lot of waste rock into space for refinement.

The sole purpose would be space colonization. Sending down the ore is possible, but without a space elevator or some very clever aerodynamics it would be extremely costly.
Space stations would probably benefit from the oxygen: the delta-v from lunar orbit to any earth orbit are lower than from the Earth's surface.
And indeed, refining the minerals in the moon and assembling parts or structures would be ideal.

 

[Ambrose]

The US (2015), Luxembourg (2017), the UAE (2019) and Japan (2021) have adopted legislation on Moon/space mining, and a number of states hav signed up to the US Artemis Accords which reinterpret the Outer Space Treaty to get round its prohibition on acquisition of title to parts of outer space.

 

[Swank]

Sending down the ore is possible, but without a space elevator or some very clever aerodynamics it would be extremely costly.

What's costly about a heat shield?

 

[CultureCitizen]

What's costly about a heat shield?

You still have to decelerate from moon orbit to atmospheric entry: a delta-v of 5 km/s.
I am not sure that the ore or finished product has a good cost after spending all that fuel/energy on deceleration.
A lunar spin launcher capable of speeds of 6.6 km/s could do the trick ( 1.6 for lunar orbit plus 5 km/s for atmospheric entry)
Surprisingly, the delta-v from the Moon to Mars LMO is 7.2 km/s

 

[Swank]

On the other hand, from a perspective of science, the dark side of the moon would be the ideal place to put loads of robotic observatories, of all sorts.

There is no dark side of the moon.

 

[CultureCitizen]

There is no dark side of the moon.

Only dark "spots": polar craters.

 

[Swank]

You still have to decelerate from moon orbit to atmospheric entry: a delta-v of 5 km/s.
I am not sure that the ore or finished product has a good cost after spending all that fuel/energy on deceleration.
A lunar spin launcher capable of speeds of 6.6 km/s could do the trick ( 1.6 for lunar orbit plus 5 km/s for atmospheric entry)
Surprisingly, the delta-v from the Moon to Mars LMO is 7.2 km/s

Here's the thing about moving refined ore off the moon:
1. There is no time frame for the crossing. Power and life support aren't a factor.
2. You have to expend something to decelerate, but that might simply be allowing some of the ore to ablate in the upper atmosphere. And if one pass would be too extreme, you can bounce it off the upper several times since #1 applies. Eventually it will slow down.
3. If you need a reaction engine, the moon is full of O2 and aluminum, the ingredients of the Shuttle's solid rocket boosters.
4. The lack of air on the moon and in space means that manipulating metals in low or zero gravity becomes relatively easy. You can heat metals with focused sunlight without fear of damaging oxidation without any sort of crucible and then blow large metallic bubbles that have lower densities to assist in aerobraking. That can be done before launch or in transit.
5. Since your escape velocity comes from solar electricity, there is no real fuel debt. Payload size and number are limited only by the size of the mass driver and the amount of solar available.
6. Since the material to be refined is on the surface and can be done entirely with solar power, the "fuel" to slow reentry to earth is essentially just more mining material. If you boil off 30% of the iron you send to earth, the remain chunk is still very cheap and can be delivered almost anywhere there's water or wasteland.

All of our usual thinking about space travel comes from the need to move quickly and conserve mass because it is the hardest thing to put in orbit. But the moon landings required a Saturn V to get there and just a command module to get home - and that was without using anything on the moon to assist. The moon's gravity is relatively negligible in the face of it having no atmospheric friction losses. The right kind of orbit may take a year to get a delivery from the moon to earth, but it would be a steady flow of them.

But more likely the point of mining the moon or anywhere else is to build large things in space. If you're going to build habitats, there is no particular reason to send them elsewhere in the solar system - high earth orbit is safe and roomy. If you feel a need to live near some other planet, then asteroid refining become more appealing - especially if you can do the work on the way with a well chosen asteroid orbit.


Even if you are building an interstellar vessel, there is still an argument to be made for just building it (or most of its components) and using the moon as a launcher because you need a decent counter-mass to get something large moving at high velocities via magnetics. With no atmosphere, your primary energy loss in doing that would be the initial levitation energy loss, which the curvature of the moon would take care of centrifugally once the ship got up to a decent percentage of escape velocity. And you don't have to launch the ship whole - just get the modular pieces up to speed close enough together and then lock it together under zero thrust. With differentials in launch velocity the components could practically assemble themselves as the late pieces caught up to the early ones.

 

[CultureCitizen]

Here's the thing about moving refined ore off the moon:
1. There is no time frame for the crossing. Power and life support aren't a factor.
2. You have to expend something to decelerate, but that might simply be allowing some of the ore to ablate in the upper atmosphere. And if one pass would be too extreme, you can bounce it off the upper several times since #1 applies. Eventually it will slow down.
3. If you need a reaction engine, the moon is full of O2 and aluminum, the ingredients of the Shuttle's solid rocket boosters.
4. The lack of air on the moon and in space means that manipulating metals in low or zero gravity becomes relatively easy. You can heat metals with focused sunlight without fear of damaging oxidation without any sort of crucible and then blow large metallic bubbles that have lower densities to assist in aerobraking. That can be done before launch or in transit.
5. Since your escape velocity comes from solar electricity, there is no real fuel debt. Payload size and number are limited only by the size of the mass driver and the amount of solar available.
6. Since the material to be refined is on the surface and can be done entirely with solar power, the "fuel" to slow reentry to earth is essentially just more mining material. If you boil off 30% of the iron you send to earth, the remain chunk is still very cheap and can be delivered almost anywhere there's water or wasteland.

All of our usual thinking about space travel comes from the need to move quickly and conserve mass because it is the hardest thing to put in orbit. But the moon landings required a Saturn V to get there and just a command module to get home - and that was without using anything on the moon to assist. The moon's gravity is relatively negligible in the face of it having no atmospheric friction losses. The right kind of orbit may take a year to get a delivery from the moon to earth, but it would be a steady flow of them.

But more likely the point of mining the moon or anywhere else is to build large things in space. If you're going to build habitats, there is no particular reason to send them elsewhere in the solar system - high earth orbit is safe and roomy. If you feel a need to live near some other planet, then asteroid refining become more appealing - especially if you can do the work on the way with a well chosen asteroid orbit.


Even if you are building an interstellar vessel, there is still an argument to be made for just building it (or most of its components) and using the moon as a launcher because you need a decent counter-mass to get something large moving at high velocities via magnetics. With no atmosphere, your primary energy loss in doing that would be the initial levitation energy loss, which the curvature of the moon would take care of centrifugally once the ship got up to a decent percentage of escape velocity. And you don't have to launch the ship whole - just get the modular pieces up to speed close enough together and then lock it together under zero thrust. With differentials in launch velocity the components could practically assemble themselves as the late pieces caught up to the early ones.

It is very convenient for space travel.
I'm not sure about using it to send materials to Earth, even with atmospheric breaking, it takes a lot of fuel to decelerate from low lunar orbit into low-earth orbit. With conventional fuel, the cost for one ton of material would be around 600 USD.
It could be competitive against something shipped from another continent: shipping a ton of material from China to the US costs around 2,000, so I guess it has the potential to be cheaper.