Rotary Rocket will use a low-risk conventional engine for its Roton flight demonstrator, rather than the original RocketJet engine, "so that the development programme can be concluded more rapidly and with less technical risk". The move is believed to be in response to investor concern about the use of new technology in the project.

The Roton will use a cluster of NASA Fastrac engines to provide the necessary thrust. Both the "customer base and the investment community have shown their early support for the new engine choice", says Rotary. Development of the RocketJet has been deferred, although there is still the option to use the engine on future vehicles.

The company says that it has secured low and higher earth orbit satellite delivery contracts, which, if fully exercised, would be worth $900 million over 10 years. The company is still seeking $120 million funding for its activities, however, and has been forced to cut its workforce. Rotary has not disclosed the extent of the lay-offs, but it is believed that only a skeleton staff will remain.

Source: Flight International