Summary: With Space Shuttle Discovery safely home after a nearly 13-day flight, NASA is breathing a collective sigh of relief. STS-121 was by far the safest space shuttle flight yet (at least in terms of launch debris). Frequent Popular Mechanics contributor and four-time shuttle astronaut Thomas D. Jones joins me in the studio to chat about this most recent flight, the future of the space shuttle program, the future of the ISS and what it's like to work on a construction site that orbits the Earth once every 90 minutes. Plus, Tom provides insight into what's next on the agenda for Discovery's crew.
