MnAstro Forums

The images of the little near-earth asteroid Bennu, returned by the Osiris-Rex spacecraft, are absolutely fascinating. (See https://www.asteroidmission.org/?attach ... 12182#main) It looks like a loose collection of thousands of meteoroids that have piled up throughout the history of the Solar System. If we decide to exploit these resources, maybe all we need to do is grab a few boulders and haul them back to the processing facility.

Of course Bennu is a priceless record of Solar System history and I hope that science will have priority over mineral exploitation.

The primary difficulty in asteroid mining is the literally astronomical cost of getting the mining equipment to the site, not the actual mining itself. Once there, the ore can be loaded onto a ship and a portion used as mass for a solar powered mass driver to propel the craft to its destination

Bennu is about 70,000,000,000 kg or 70,000,000 tons. This is roughly the mass of 700 aircraft carriers. Probably not worth the effort for a mission whose sole goal is mining that particular asteroid, but possibly worth it if combined with another mission that happened to be going that way. Beyond mining the asteroid for it materials, another goal could be to eliminate the tiny chance of it colliding with Earth in a century or two.