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:
Business tourism government or non-profit organizations engage in similar activities, this is still categorized as business tourism (travel). Historically, business tourism takes the form of traveling to, spending money and staying abroad, being away for some time, and has a history as long as that of international trade. In late 20th century, business tourism was seen as a major industry. According to the 1998 data from the British Tourist Authority and National Tourist Boards, business tourism accounted for about 14% of all trips to or within the UK, and 15% of the tourist market within the UK. A 2005 estimate suggested that