Since the 1960s, the market for commercial space operations has been limited almost entirely to communications satellites and commercial rocket launchers, with some tentative ventures in the areas of remote sensing and weather observation. Because of the value of the information they carry—television signals, some telephone links, and all sorts of digital data—communication satellites have been able to support a fleet of costly launch vehicles. Some time around the year 2007, the available radio frequency spectrum for communication satellites will be saturated. After that, the industry will consist only of maintenance and upgrades to the existing infrastructure.

Over the next few decades, the most lucrative industry in space will probably be tourism. On Earth in the early twenty-first century, tourism is the second largest export industry. (The largest is energy, in the form of oil.) A tourist industry in space will reduce the cost of getting into...