Swedish authorities planning to host flights of the Virgin Galactic suborbital space plane hope to lower the costs and regulatory barriers to the operation by having it classed as a sounding rocket and given the tax advantages of hot-air balloon flights, Swedish and Virgin Galactic officials said April 1.

London-based Virgin Galactic, whose SpaceShipTwo craft and its White Knight Two motherhip are nearing completion by Scaled Composites of Mojave, Calif., remains on schedule to begin test flights this summer, Virgin Galactic President Will Whitehorn said.

Addressing a press briefing at Sweden’s Esrange launch site, which is being prepared as Virgin Galactic’s second launch site after Sierra County, N.M., Whitehorn said Virgin Galactic is sticking with its earlier estimates of being able to field its space launch system for about $250 million. He said about $100 million has been spent so far.

Some 250 prospective customers have made $35 million in flight deposits with Virgin Galactic. The flight ticket is $200,000 per person for a two-hour flight that will include perhaps five minutes of weightlessness as the ship approaches the limits of the Earth’s atmosphere at 100 kilometers in altitude.

Sven Grahn, senior advisor to the Swedish Space Corp., which operates the Esrange launch facility in the northern Swedish town of Kiruna, said Esrange’s long history as a site for launches of suborbital rockets has established a regulatory regime in Sweden to cover third-party liability that also apply to Virgin Galactic operations.

To reduce the value-added tax that would be levied on Virgin Galactic operations, Grahn said Swedish Space Corp. is investigating whether the space-tourism activity could be fitted into the same low-tax regime that covers the operations of hot-air balloons. Value-added taxes in Sweden run as high as 25 percent.

Grahn said that while space law in Europe remains the responsibility of individual nations, aviation law authority is migrating slowly to the European Union. He said it remains unclear whether European or Swedish aviation regulations will apply to space tourism from Swedish territory.

As he has in the past, Whitehorn conceded that while the design construction using composite materials of SpaceShipTwo and White Knight Two have captured most of the attention, many of the hurdles the company needs to overcome relate to the more prosaic issues of regulatory approval and insurance coverage.

Space-tourism industry officials have said their obvious early market, high-net-worth individuals, presents the risk that, in the event of an accident, passengers’ families would seek to overturn in court the liability waivers that customers will sign. If such an action is viewed as likely, Virgin Galactic will have difficulty securing insurance coverage.

After its flight tests this summer, Virgin Galactic will need to be certified as flight-worthy by the U.S. Federal Aviation Administration. Only after certification occurs will the company have a clear idea of when its first flights will be. But Whitehorn said 2009 remains the target. For the Swedish operation, flights could begin in 2012 or 2013, he said.

As is the case in New Mexico, Virgin Galactic is not investing in the development of the Swedish spaceport.

Esrange already has a suitable airport and a large hangar that can be used by Virgin Galactic. Swedish Space Corp. officials hope to make the business case for space tourism based on revenue expected from paying customers and accompanying personnel.

The Swedish flights would feature what Kiruna Mayor Kenneth Stalnacke referred to as “surfing through the northern lights,” the Aurora Borealis, during the midsummer and mid-winter months.

Stephen Attenborough, Virgin Galactic’s commercial director, said the company’s earlier estimate that 80 percent of its prebooked passengers would pass a physical exam now looks overly cautious.

Attenborough said a sample group of 80 Virgin Galactic customers – including one 88 year old – have been put through the stresses of a centrifuge in Philadelphia to test their ability to withstand the g-force loads expected during a Virgin Galactic flight.

Only two were disqualified, with three others asked to provide supplemental medical information, Attenborough said. Based on this experience, Virgin Galactic now assumes that 90 percent or more of those reserving flight slots will pass the preflight medical exam.

Peter B. de Selding was the Paris bureau chief for SpaceNews.