Guest: Robert Zimmerman returned for this Space Show program. In addition to our discussion, we talked about Bob's new book about Hubble, "The Universe in a Mirror," and his terrific older book, "Leaving Earth." We started the interview by discussing a recent Washington Post article in which the author suggested the ISS be used as a spaceship for going someplace interesting rather than just hanging out in LEO. Mr. Zimmerman wrote about this idea years ago in his famous book, "Leaving Earth," so we talked about the feasibility of actually doing something like this with the station.