Since the first space object was launched into orbit in 1957, humankind has been engaged in a constant effort to realise ever more ambitious plans for space travel. Probably the single most important element in this ongoing evolution is the development of technology capable of transporting large numbers of passengers into outer space on a commercial basis. Within the foreseeable future, space will no longer be the sole domain of professionally trained astronauts or the exceptionally wealthy. The prospects for both suborbital and orbital private human access to space give rise to some interesting and difficult legal questions. It also opens up an exciting opportunity to develop an adequate system of legal regulation to deal with these activities. The existing international legal regimes covering air and space activities are not well suited to large-scale commercial access to space, largely because they were developed at a time when such activities were not a principal consideration in the mind of the drafters. The lack of legal clarity represents a major challenge and must be addressed as soon as possible, to provide for appropriate standards and further encourage (not discourage) such activities. This article will examine some of the more pressing legal issues associated with the regulation of space transportation of passengers on a commercial basis, seen in the light of Article 1 of the Outer Space Treaty of 1967, which states that the 'exploration and use of outer space [...] shall be carried out for the benefit and in the interests of all countries [...] and shall be the province of all mankind'. An appropriate balance must be found between the commercial and technological opportunities that will arise and the principles upon which the development of international space law have thus far been based.