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:
Virgin Australia 11 Embraer 190 and three Embraer 170 aircraft with options for six more E-jets, which later became orders for an additional three E170s and three E190s. In February 2008 a further four E190s were ordered, leaving six options and ten purchase rights. Virgin Blue received its first Embraer 170 in early September 2007 at a special ceremony at the Embraer plant in Sao Jose dos Campos. A revised logo was introduced on the tail, bringing the Virgin Blue brand into line with the logos of other Virgin-branded companies. Like Virgin Atlantic, Virgin Australia gives the aircraft in its fleet names,