Space architecture of space and a space transportation infrastructure can be accelerated. Virgin Galactic has indicated plans for an orbital craft, SpaceShipThree. The demand for space tourism is one without bound. It is not difficult to imagine lunar parks or cruises by Venus. Another impetus to become a spacefaring species is planetary defense. The classic space mission is the Earth-colliding asteroid interception mission. Using nuclear detonations to split or deflect the asteroid is risky at best. Such a tactic could actually make the problem worse by increasing the amount of asteroid fragments that do end up hitting the Earth. Robert Zubrin writes:
Tourism and the degree to which countries play in the global context. Not only as a result of the important economic contribution of the tourism industry, but also as an indicator of the degree of confidence with which global citizens leverage the resources of the globe for the benefit of their local economies. This is why any projections of growth in tourism may serve as an indication of the relative influence that each country will exercise in the future. There has been a limited amount of orbital space tourism, with only the Russian Space Agency providing transport to date. A 2010