As Scaled Composites prepares to bid for the X-Prize, US Congress debate rages over definition of "suborbital vehicle"
Scaled Composites intends to bid for the $10 million Ansari X Prize in late September by launching two manned suborbital spaceflights within a two-week period.
But a debate still rages in the US Congress over how to regulate a space tourism industry that is likely to boom if Scaled Composites founder Burt Rutan's attempt is successful. The dispute centres on the definition of "suborbital vehicle". Lawmakers are trying to update the Commercial Space Launch Act of 1984 to include the then-unforeseen market for space tourism, but the effort has led to competing definitions of suborbital transport between the House and Senate.
A House-approved bill limits suborbital craft to rocket-based designs that generate more thrust than lift for most of the flight.
On 22 July, Sen James Inhofe, of Oklahoma, introduced a Senate bill, the Space Commercial Human Ascent Serving Expeditions Act, also called Space CHASE. Inhofe's legislation amends the House's definition to include hybrid designs that use both jet and rocket propulsion, which is a design being proposed by Oklahoma-based company Rocketplane.
Addressing the Senate, Inhofe said his definition will allow Rocketplane to "avoid being forced to go through a lengthy two-step licensing process formally required for launch vehicles and commercial aircraft, and will have the opportunity to be licensed to carry civilian passengers much more quickly".
But it is not clear whether lawmakers in the House will go along with the new definition. Sherwood Boehlert, House Science Committee chairman, says he looks forward to "revisiting the issue", but did not endorse Inhofe's definition.
Scaled Composites, which flew a suborbital mission with Mike Melvill at the controls on 21 June, plans to launch SpaceShipOne on 29 September and 4 October. A third flight is scheduled in case one fails to reach the required 100km (62 miles) altitude.
Rutan has suggested he might attempt to win the X-Prize by carrying two passengers. But prize organisers now say the requirement is only to carry the equivalent weight of two passengers, plus the pilot. Rutan is determined to eventually use SpaceShipOne as a commercial passenger-carrying venture, kick-starting space tourism. Rutan is backed by Microsoft co-founder Paul Allen, who has invested $20-30 million.
Canadian Ansari X-Prize contender da Vinci Project will unveil its Wild Fire balloon-lofted rocket-spacecraft on 5 August. The Toronto-based company hopes to make its first demonstration flight this year. The da Vinci project will involve sending a balloon to 80,000ft to deploy the rocketship. The craft would be cocooned during the return in an inflatable shield.
Russia's Myasishchev has also unveiled a suborbital space tourist craft, C-XX. The rocket glider, operated by ZAO Sub-Orbital, would make its flight in 2005. Tickets for tourist flights would cost $100,000.
STEPHEN TRIMBLE / WASHINGTON DC & TIM FURNISS / LONDON