andrew@nsc.nsc.com (andrew) (04/06/89)
Recent postings have discussed the economics of asteroid mining in light
of the possible future need to "go and get some more palladium". Here is
some data which might come in handy:
1. Metals requirements
----------------------
In 1967 US produced 3e8 tons of iron, steel, rolled iron, aluminium,
copper, zinc and lead = 3e11 Kg.
Assuming 3% ore @ 3.5gm/cc, US produced an equivalent sphere 1.7 Km diameter.
At 250 million US population, US produced about 1000 Kg per capita.
To supply the whole world at this (first world) rate requires 5e12 Kg total.
Assuming 3% ore @ 3.5gm/cc, this is an equivalent sphere 4.5 Km in diameter,
weighing 5e9 tons or 5e12 Kg.
There exist at least 40,000 asteroids larger than 5 Km in diameter.
2. Asteroid mining energy considerations
----------------------------------------
The deltaV from the Belt to Earth is 7 Km/s. Moving 5e12 Kg of asteroid
needs 1e20 joules (about 1% of world's annual (1978) energy use).
Reproduced without permission from "A Step Farther Out" by Jerry Pournelle
=====
Andrew Palfreyman USENET: ...{this biomass}!nsc!logic!andrew
National Semiconductor M/S D3969, 2900 Semiconductor Dr., PO Box 58090,
Santa Clara, CA 95052-8090 ; 408-721-4788 there's many a slip
'twixt cup and lip