Brian O'Leary
I
FooD AND RAW MATF.RJAL SUPPLY FROM SPACE TO THE EARTH
hydrO'gen, which appear tO' be lacking O'n the MoO'n. DiscO'veríes O'f
several new candidate asteroids O'ver the next few years wiU aIlO'w
fO'r a selectiO'n O'f an abundance O'f materials and missiO'n pO'ssibilities.
One scenario considers tne retrieval, by a sO'Iar-pO'wered electric
mO'tO'r called a mass driver
(1,
4), O'f a lO milliO'n ton (200) meter
didmeter) asteroid thrO'ugh a small increment of energy frO'm its
prese:nt orbit tO' a dligh Earth orbit fO'r space manufacturing (6).
Material from the asteroid itself wO'uId serve as fueL Such an under–
taking was estimated tO' cO'st
$
0.10 -
$
O.~O
per kilO'gram and raises
the questiO'n of whether raw materials could be returned directly
tO' Earth from the asterO'ids.
Gaffey and McCorcl
(7)
have d'scussed the pO'ssibility O'f
retricvi'ng asteroidal materials for use rlirectly as metal resO'urces
Dn the Earth. They suggested the development Df .vacuum-fO'amed
reenlry bodies surrO'unding the astcrO'idal fragments wO'uId make
pO'ssible intact landings in the O'cean with subsequent towing ashore
by barge. With abO'ut 10
10
tO'ns O'f a metalridh asteroid landed O'n
the Earth, they prO'ject the market price of iron to be
$
0.40/kg
and nickel,
$
0.80/kg. TherefO're, wih a missiO'n energy requirement
describen here, the cO'st of transfer by mass driver O'f an irO'n-nickel
asterO'id to the Earth's surface may bewme inmediately cO'mpetitive,
It is interesting tO' nO'te that the Sudbury AstrO'blem in Ontario,
Candda, was the source O'f apprO'ximately O'ne-half the tO'tal world
production of nickel between 1961 and 1965 (8). The metal in
thi~
deposit is possibly meteoritic (9), so there may exist a precedent
in nonterrestrial mining.
Farther in the fnture, asteroidal resources could be O'btained in
even larger quantities. A two-phase program cO'uld be carried out:
first, the launch of a mass dr:ver asteroid retríeval mission which
wO'uId be cDncurrent with the development of space manufacturing
facilÍlies sized to process up to 10
7
tons of asteroidal material jnto
satellites solar power plants over a period O'f about 10 years ando
second, tIle use of one such plant to power a mass-driver supertug
(=10.000 Mw,
10'1
tons) to a 1 km diameter (10
9
tO'n) metal-rich
aste] oid which coulel provide more fhan enough material fO'r he
worId's energy supply from space sO'lar power statiO'ns, and a sizabI':!
increase in the availability of iron ami nickel
011
tlle Earth. Space
habitats, large telescope arrays and planetary explorers could alsO'
be manufactured from a single asteroid of this size or its equivalent,
pos!>ibly by the turn of the century.
,The possibility of growing fO'od in space for consumption on the
