Re: retrieving material from asteroids

"Lawrence Gales" <larryg@xxxxxxxxxxxxxxxx> wrote in message
news:Pine.WNT.4.63.0602222356280.2776@xxxxxxxxxxxxxxxxxx

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

Are you talking about flinging mass off an asteroid or moving the whole
asteroid? Lunar catapults would be designed to run every day. If an
asteroid is near Earth once every 5 years, then the catapults would have
long down times. Someone could build the O'Neill colony near the asteroid.
From there, one could either move the colony into Earth or orbit or not.


.

Relevant Pages

  • Re: retrieving material from asteroids
    ... `> on the order of 100,000 tons at a time relatively cheaply. ... ` Are you talking about flinging mass off an asteroid or moving the whole ... ` asteroid is near Earth once every 5 years, ...
    (sci.space.policy)
  • The downside of moving asteroids
    ... This asteroid is approximately the size of the object shown in the ... It masses 1 billion billion tons, ... the sun as the Earth and has a period of 4.6 years. ... We would have to impart 4.86 km/sec to Ceres to cause it to collide ...
    (sci.space.policy)
  • Re: Terraforming Venus will be easier
    ... we can figure out how much of an asteroid must be flashed away in ... million tons with a specific density of 2.8 metric tons per ... Venus rate of rotation is; ...
    (sci.physics)
  • Re: retrieving material from asteroids
    ... Why not just go to a chunk sized asteroid in the first place? ... Go to a 1 billion ton asteroid, land, and dig out 1000 tons to ... return to Earth Orbit. ...
    (sci.space.tech)
  • Re: retrieving material from asteroids
    ... Why not just go to a chunk sized asteroid in the first place? ... Go to a 1 billion ton asteroid, land, and dig out 1000 tons to ... return to Earth Orbit. ...
    (sci.space.tech)
Quantcast