The dream of making space travel available to the masses is one that continues to excite and inspire more than 40 years after Yuri Gagarin became the first man to orbit the Earth. Since then, progress has been much slower than expected. Indeed, it has been almost non-existent. Governments have monopolised the hugely expensive and highly risky business of manned space flight - until this week, that is. On Monday, a chubby white spacecraft resembling a child's toy aeroplane completed a brief trip into space and safely returned to earth. It marks the beginning of a new era. The flight by SpaceShipOne and its single astronaut Michael Melvill is the first privately developed mission to send a man into space. It cost a mere US$20 million, provided by a billionaire. And in one dramatic step, the flight has brought the prospect of affordable space travel much closer to becoming reality. It is justifiably being compared to the pioneering days of aviation. The same spirit of adventure, technical expertise and determination to succeed are there for all to see. But the aim is also to inspire others to pursue a commercial route into space and to succeed where governments have failed - by creating a new tourism industry. The flight was partly motivated by a competition launched in 1996 which offers a US$10 million prize to the first privately backed team to propel three people (or one person and the equivalent weight of two more passengers) into space twice within two weeks. It is too early to start talking of package tours to the moon. The trip made by SpaceShipOne would not appeal to anyone who harbours even the slightest fear of flying. A key piece of equipment failed, the ship spun around 90 degrees, and there was also a loud bang when part of the spacecraft buckled. Melvill might have been putting it mildly when he said: 'I was pretty scared.' But the flight from California into sub-orbital space is, nonetheless, a very important milestone. There have only been two space tourists in the past - and both piggy-backed on missions launched by the Russian government. Each of them paid the princely sum of US$20 million for the privilege. The aim of Monday's mission, and similar flights in the pipeline, is to make space travel rather more, well, down-to-earth. Momentum is building. Last week, a presidential commission in the US recommended that Nasa rely more heavily on commercial enterprise. And there is talk of new competitions being launched with prizes as tempting as US$200 million. The excitement generated by space travel has been reignited by the historic flight. Perhaps the day when almost everyone can experience it is finally on the way.