ELON MUSK is not, to paraphrase James Watson's bon mot about Francis Crick, a man given to modest moods. Today, though, he might be forgiven a little hubris. The co-founder of PayPal, and developer of the Tesla, the first modern electric sports car, has long wanted to get into the space business as well. Now he has. The launch on June 4th of a Falcon 9 rocket, built by his company SpaceX, from Cape Canaveral, in Florida, is a turning point in the development of private space flight. Though the industry's coming of age is still some way in the future, this launch marks, if you like, its transition from childhood to adolescence.Other rockets of this class, such as Boeing's Delta IV and the Atlas V, operated jointly by Boeing and Lockheed Martin, are children of the military-industrial complex. Though built by private firms, they are the result of taxpayer-financed programmes, often on a “cost-plus” basis, that only superficially resemble anything which a real entrepreneur would recognise as free-market capitalism. By contrast SpaceX, though subsequently buoyed up by a $1.6 billion contract with NASA, America's space agency, to fly missions to the international space station, had to raise the initial development money itself—much of it from Mr Musk's back pocket.The important point about Falcon 9, so called because its lift-off is propelled by nine of SpaceX's proprietary Merlin rocket motors, is that it is powerful enough to put people into orbit. Other private space companies are either restricted to launching small, unmanned satellites (Orbital Sciences Corporation's Pegasus, for example), or—in the case of Richard Branson's Virgin Galactic—hope to take tourists on suborbital hops of the sort that NASA gave up almost 50 years ago and the Russians never bothered with in the first place. SpaceX has gone for the jugular. Though it will take many more launches and a lot of inspections before the system can be “man-rated”, as the jargon has it, prototypes of manned space capsules are already lying around in SpaceX's factory in Hawthorne, California.Just in time, too. For America's current manned system, the government-owned space-shuttle fleet, is about to be withdrawn from service. The last shuttle flight is pencilled in for November. After that, American astronauts who wish to visit the space station (largely an American-financed project, despite its “international” soubriquet) will be reduced to hitching lifts on Russian rockets. If Falcon 9 does, indeed, manage to get man-rated, they may be spared that indignity. Those astronauts that are there will, in any case, be able to have their groceries delivered by Falcon 9. The question of man-rating does not affect its ability to take supplies to the station.The vehicle itself is a two-stage affair. The heavy lifting is done by the nine-engine cluster, fuelled by kerosene and liquid oxygen. That burns for three minutes, before being jettisoned. The payload, a capsule known as Dragon, is then carried into orbit by a single-Merlin-engined second stage that burns for a further six minutes. The unmanned version of that capsule is designed to accommodate six tonnes of goodies for the inmates of the space station, or could be replaced by a heavy satellite, if that is what the client wants.The heavy-satellite-launching market is quite crowded already, though, what with Atlas, Delta, the “European” (in reality, almost exclusively French) Ariane and Russia's Proton. So Mr Musk's real bet is on the ultimate man-worthiness of the system. That will not only open up the taxi-to-the-space-station market, but will also allow him to tout for tourist business. At the moment, the Russians have this sewn up (though Space Adventures, the travel agency that actually books flights on those rockets for people who have the requisite $20m or so, is American). Who knows, a little competition might even bring the price down from something that is out of this world, to a level that is merely stratospheric.