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#126 2019-11-04 17:01:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,493

Re: Colonizing / terraforming small asteroids

Make more glass for the acids seems to be some of the answer. That said processed ore in space will be used in space rather than send it to earth as its got to come up along ways to make it worth buy from the space source.

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#127 2019-11-05 04:05:34

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,130
Website

Re: Colonizing / terraforming small asteroids

Sending stuff down a gravity well is cheaper than bringing it up out of one. Particularly nickel, which can be formed into inconel heat shields and dropped off in a friendly desert (Australia?).

Doing refining in space doesn't just reduce the mass you're sending planetside, it also lets you benefit from very cheap solar power. I expect nickel to be the first metal mined, but there could be a future for aluminium smelting too.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#128 2019-11-05 04:58:17

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 143

Re: Colonizing / terraforming small asteroids

Solar power for asteroid mining and mineral processing would appear to have excellent power-weight ratio, as it can be in sunlight 100% of the time and no storage is needed.  At Earth orbit with 1350W/m2 insolation, a thin film space solar panel weighing 0.1kg/m2 would deliver 2-3kW/kg.

The only downside is that it does limit operations to asteroids that have relatively circular orbits with apogee not too far beyond Earth orbit around the sun.  Many candidate NEOs have highly elliptical orbits that go beyond the orbit of Mars.  But these wouldn't be our first choice anyway, as the dV requirements to match orbit with them from Earth would be much higher.

We could cast nickel into hollow spheres, sputter it with some sort of molten oxide as a re-entry shield, and drop them either onto land or into the ocean.  Ideally, we want the terminal velocity on impact to be low enough that they survive intact.  Aluminium might be a more profitable asset for building space based structures, at least initially.  It takes 20kWh of electric power to produce 1kg of aluminium.  So a 10m2 solar panel, weighing 1kg, could produce about 8766 times its own weight in aluminium over a 10 year lifespan.  Even if we have to transport the solar panel from Earth, that sort of ratio could make space based aluminium production quite profitable.

Last edited by Calliban (2019-11-05 05:13:24)


Interested in space science, engineering and technology.

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#129 2019-11-05 07:38:34

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,493

Re: Colonizing / terraforming small asteroids

Or send them to mars to increase the planets mass with materials that we will need

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#130 2019-11-06 10:19:42

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,220

Re: Colonizing / terraforming small asteroids

For Calliban re topic and bags to enclose asteroids

In another topic:

A fishing technique known to and practiced by many, is to let a line into a body of water in such a way as to attract a fish.  Often, in open ocean settings, the fish which accepts the bait or other attractive element is heavier and stronger than the line can hold.  The operator of the fishing equipment allows the line to pay out against resistance, to tire the fish, always taking care to keep the tension on the line well under its maximum strength.
While the engineering challenges are daunting, the same principle could be applied in capturing incoming vessels arriving at Phobos, or with reference to Calliban's topic about asteroids, could be applied to capturing asteroids.
In both cases, whatever differences in momentum and vector exist between a given object and a vessel intending to capture it could be (in principle) managed by appropriate operation of the line management subsystem.

It occurred to me that a strategy for wrapping an interesting asteroid in one of your bags would be (could be) to allow the asteroid to move into a flat surface of material stretched out by four small automated vehicles pulling at the corners.

Depending upon the relative velocity between the object and the net, the net would be pulled smoothly around the exterior of the object, and the corners would be tied together with mechanical devices.

The attachment point, like the attachment point for deep see fishing with nets, would/could then be used to pull the object if that is desired.

This technique could also work for objects which threaten to collide with Earth.  The bag enclosure you have proposed would solve the problem of loose rubble objects scattering when manipulated.

(th)

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#131 2019-11-09 12:24:59

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 16,493

Re: Colonizing / terraforming small asteroids

Found that we have another topic for lauch in NASA rocket simulator: how to build a rocket

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