The Keck Report, the product of a study by the Keck Institute for Space Studies (KISS) at CalTech/JPL in Pasadena, California constitutes a foundation stone astronautical engineering result for the asteroid exploration, mining, and science communities. http://kiss.caltech.edu/final_reports/Asteroid_final_report.pdf

What I think most important about this report is not so much the conclusions about whether retrieving an asteroid from solar orbit and placing it in lunar or Earth orbit is feasible (read it to find out for yourself) but it addresses the thorny issues around flying to an asteroid. The fundamental challenge is that all the asteroids are moving all the time, often faster than the Earth, and their orbits vary wildly out of the ecliptic plane in which the Earth orbits the Sun. What this differential means is that When you go determines where you can go. You can see many examples of this principle in the JPL Small Body Database Browser. https://ssd.jpl.nasa.gov/sbdb.cgi

[The JPL-SBB was originally called the Small Body Browser. However, the scurillous word on the street is that the bureaucrats thought that sounded too much like a porn site, so they changed the name to Small Body Database Browser, so there should be no misconception. So, now it must be data porn: All those ones and zeros!]