retrieving material from asteroids


Most studies of O'Neill type colonies assume that we would get the millions
of tons of material from the moon via a catapult. However, there are some
Near Earth Asteroids where the return dV to the earth-moon space is
astonishingly small. For Nereus, 1982 DB, it is about 60 m/s, or 135 mph.
This opens the possibility of bringing back enormous payloads
on the order of 100,000 tons at a time relatively cheaply.

For example, a small mass driver with a specific impulse of 200 (approx.
2000 m/sec) would need to expend only 3000 tons of material to move it
to the earth-moon space.

However, I don't know enough orbital mechanics to know if we would need
short impulses for part of the return, as I believe it uses lunar gravity
assist. So does anyone know if the low-g acceleration of a small mass
driver would be sufficient, or do we also need higher gee thrust for
part of the mission?

-- Larry Gales
.

Relevant Pages

  • Re: retrieving material from asteroids
    ... Lawrence Gales wrote: ... Near Earth Asteroids where the return dV to the earth-moon space is ... on the order of 100,000 tons at a time relatively cheaply. ... a small mass driver with a specific impulse of 200 (approx. ...
    (sci.space.policy)
  • Re: retrieving material from asteroids
    ... Near Earth Asteroids where the return dV to the earth-moon space is ... on the order of 100,000 tons at a time relatively cheaply. ... shatter the asteroid first in it's own heliocentric orbit into smaller ... fragments, and then to transport the resulting fragments individually ...
    (sci.space.tech)