JP Aerospace is a volunteer organization practicing a concept I've only ever fantasized about with my friends: airships are launch platforms. And these discussions never really go beyond "well, lets put a rocket on a balloon and see what happens." However, what JP Aerospace envisions is a series of blimps and otherwise inflatable aircraft as stepping stones, eventually floating all the way to orbit. This offers a low-cost, bulk access to space that is scalable from small satellites, to people, to heavy lifting, that is safer than traditional rocket launch vehicles. Most importantly, their Airship To Orbit project is over twenty years old. While the information pdf they have is undated, they state they'll be testing their orbital ion engine in the next five months, testing a crewed vehicle in the next eighteen, and are seven years from completion. Did I mention they were volunteers?
Visit their website and blog for more information
