Roton, a bizarre looking space craft developed by California’s Rotary Rocket company could be the first fully reusable, single-stage-to-orbit, commercial launch vehicle.
Piloted by a crew of two, Roton will take off like a conventional rocket, powered by a liquid-fuelled rocket engine burning oxygen and kerosene. Once the payload is delivered to orbit, Roton will return to earth via a nose-mounted rotor which will help stabilise the craft during re-entry. The surface of the vehicle will be protected by a water cooling system and, once in the atmosphere, the company claims that the vehicle will behave like a helicopter and land vertically, assisted by rotor tip thrusters.
Because no components will be discarded a massive reduction in turn-around time and flight cost is anticipated.
The rotor system was chosen over parachutes, wings and engines. As well as being lighter than other systems, rotors offer flight path control, precision landing capability and near-zero velocity touchdown; reducing the requirement for a landing infrastructure.
Another key element of the design is its lightweight airframe. Historically, launch vehicles have been fabricated from aluminium alloys and, occasionally, steel. So few have been designed recently that this trend has rarely been reversed. However, Roton takes advantage of the significant advances which have recently been made in the field of fibre-epoxy materials. Often used in the design of commercial aircraft, these structures can be as strong as steel yet a fifth of the weight.
The prototype, Roton AT, uses a centrifugally pumped rocket motor for lift and a rotor to provide lift during descent, reducing the fuel requirement and allowing the possibility of landing without fuel in an emergency.
Whilst Roton it is not yet capable of orbital or even sub-orbital flight, several of its concepts, including the rotors, have been successfully tested in the Mojave desert. Most recently, the ATV reached an altitude of 75 feet and flew at 53mph 4,300 feet along a runway.
The company boldly claims that the rocket will enter commercial service in 2001, where it will replace existing expendable rockets and serve the multi-billion dollar telecommunication satellite market.