Asteroid Mining

Well, Matt, I guess it all depends on the size of the
asteroid you want to mine. If we're talking a big one
like Ceres or Vesta, there might be enough mass there
that gravity could do the securing for you; IIRC Ceres
has about 2% gee. If the asteroid is much smaller, ie
5 m diameter, then you might be able to build a
machine that swallows it whole like the Doomsday
device from Star Trek. For something in the mid
range, say 100m to 10km diameter, the securing method
would likely depend on the composition of the body; a
solid hunk of stone or metal or ice might have pitons
driven in and cables laced between them, but that
wouldn't work for a pile of rubble.