points out a New York Times article about one sticky wicket faced by
members of the Tripoli Rocketry Association, whose members are some of the private citizens trying to bust into the space-launch business (or just having fun) by financing and building their own rockets.
An excerpt: "On Tuesday, lawyers representing Tripoli and the National Association of Rocketry and officials of the firearms bureau will head to Federal District Court in Washington to resolve the seven-year-old dispute over the hobbyists' use of a flammable propellant, ammonium perchlorate composite, or APCP. The chemical is the main ingredient on the space shuttle's solid rocket boosters. ... The firearms bureau classifies APCP as an explosive and, amid post-Sept. 11 security concerns, requires that anyone who uses more than two ounces of propellant undergo federal background checks."