One of the things that makes space travel unfeasible is the huge cost (and added weight) that comes with powering rockets with solid or liquid fuel. The faster a rocket will eventually go, the more fuel it needs, which adds to the weight that needs to be launched into space, and the size that the spacecraft needs to be to carry the fuel.

Scientists and science-fiction writers have toyed with the idea of a spaceship that could be fueled by laser beams of light. Now, this idea is closer to becoming a reality. Yuri Rezunkov, a physicist at the Institute of Optoelectronic Instrument Engineering in Russia, and Alexander Schmidt, a physicist at the Ioffe Physical Technical Institute in Saint Petersburg, Russia, have developed one of the steps necessary for fueling a rocket by lasers. This new process combines another process that already existed, called laser ablation, with the gas nozzles on a spacecraft.  Their research paper was published on October 29 in the Optical Society's (OSA) journal, Applied Optics.

Laser ablation is a process through which a pulsating laser beam is directed at a surface. It would burn some of the gas, creating a plasma plume, which acts like exhaust, which would create added thrust to the rocket.

The researchers theorize that by integrating laser ablation into the ship's gas burning process, they can make gas flow out of the nozzle even faster, allowing the spacecraft to reach much faster speeds, while simultaneously burning less fuel. This could allow gas to flow out of nozzles at supersonic speeds.

There are some potential shortcomings to this process, including that the supersonic gases might be unstable as they flow through the nozzle, and that this process might generate shock waves that could stop up the nozzle and reduce the speed. However, the researchers expect that this can be minimized through the use of a laser ablation plasma plume that flows through the nozzle's interior walls.

"Summarizing the data obtained, we can forecast the application of the supersonic laser propulsion techniques not only for launching small satellites to Earth orbits but also for additional acceleration of supersonic aircrafts to achieve Mach 10 and more," Rezunkov said.