Rapid-reaction shuttle gets nod

An inexpensive mini space shuttle that can take off from a normal runway at a moment’s notice has received demonstration programme funding.

America’s Defence Advanced Research Projects Agency (DARPA) is giving six teams up to $2m (£1.37m) each to submit designs for the vehicle, known as the Responsive Access, Small Cargo and Affordable Launch system, or RASCAL.

The basic concept is of a turbojet-powered reusable first stage for flying towards the stratosphere, with at least one expendable hybrid-fuel rocket stage to blast it into space.

The fact that this project has received funding represents a milestone in the development of reusable spaceplane technology. While NASA has put its efforts into the manned Shuttle missions, previous attempts at cheaper unmanned craft have failed to bear fruit.

These included BAe’s Hotol (Horizontal Take Off and Landing) concept that would have used an air-breathing jet to take off, but an internal rocket to reach orbit. The project was cancelled in 1992 but some of the engineers are still working on the pre-cooled jet engines required (The Engineer 2 November 2001).

DARPA wants RASCAL to be able to take small pay-loads of up to 75kg into orbit just 24 hours after they are delivered to satisfy ‘changing national security needs’. This could mean deploying extra surveillance satellites in response to regional tension.

The price per launch must be $750,000 (£515m), a fifth of current costs, and the shuttle will need to use a 2,500m runway rather than massive launch facilities such as Cape Canaveral.

The president of one of the companies competing for RASCAL told The Engineer that this ushered in ‘a new way of thinking’ for the US space programme. ‘DARPA’s solicitation is a visionary statement,’ he said. ‘It really lays out a challenge. The transition from the launch vehicles that have gone before is like comparing hot air balloons with the Wright brothers’ first plane.’

After the nine-month feasibility phase DARPA will pick two teams to develop their designs for another year before selecting a winner in 2004. Flight demonstrations are scheduled for 2006.

DARPA envisages commercial as well as military uses for the spacecraft. There is understood to be UK involvement, for example from BAE Systems Flight Systems, in at least one of the competing teams.

The following corporations lead the teams: Coleman Research, Northrop Grumman, Pioneer Rocketplane, Space Launch, Space Access-LLC and Delta Velocity.

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