Design of a laser-based drive for a space yacht united physicists from Saint Petersburg, Moscow and Tokyo. Laser propulsion system has many applications except ship launching – it can clean the space from space wastes by changing orbits of its particles and protect space stations from said wastes, as well as maintain interorbital flights of space vehicles.
This spatial motion technique has one basic advantage over other means of transport – its power source is located on Earth or on Earth’s orbit, thus the ship doesn’t need to carry large amounts of rocket fuel, which is many times heavier than working load. A ship with the laser-based drive looks more like a very fast yacht, which hasn’t got any needless parts – only the mast and a light sail. Laser propulsion system has many applications except ship launching – it can clean the space from space wastes by changing orbits of its particles and protect space stations from said wastes, as well as maintain interorbital flights of space vehicles.
A possibility for traveling in space by means of laser, located on Earth, and with much higher efficiency than due to fuel combustion, was first mentioned in the 1970s. In 1972 doctor Arthur Kantorovich from American “Avco-Everett Labs” suggested using laser ablation effect (matter evaporation in an intense laser beam) for space flights. Following works of Russian eminent physicists formed a theory of thrust generation in a laser-based drive in 1976. When gas is exposed to intense pulse laser radiation, it forms local explosions, generating blast waves, which in their turn are the source for recoil impulse. First successful tests of a vehicle with laser jet engine were performed in 1997 on the White Sands missile range, New Mexico, USA.
In 2002 physicists from Japan and the USA developed a concept for using stationary lasers for traveling around earth and moon orbits. Laser stations, located on our planet, its satellite and on earth orbits, are expected to perform three main functions. They will provide eco-friendly satellite launch – when only a little oxygen is burnt, allow easy correction of orbits of artificial satellites and give spaceships a chance to travel from Earth to Moon without spending much fuel.
Generally, distances are not important at all – in space light covers enormous distances without being absorbed, however, beam diameter grows with distance, which requires an additional mirror focusing the light in the engine. Currently solar-wind sail are being tested, and laser sail will be much less in size. Since power source for lasers, located in space, is solar light turned to electricity via solar cell panels, such transport system will function steadily for unlimited time and have low maintenance costs.
Leading project scientist says that their model has two mirrors instead of one – for the ship to move towards the laser beam. First one accumulates light and reflects it to the other mirror, which concentrates the light in the special chamber with evaporable substance. Said substance evaporates and quickly leaves the chamber, thus providing jet thrust to the ship.
Scientists have spent three years choosing the evaporable substance with appropriate properties. First they tested liquid fuel, which was injected to the working chamber by means of nozzles. Solid fuels appeared to be more convenient, and polyformaldehyde showed the best results – 30% better than polyvinyl chloride and twice as better as polycarbonate, which determined the choice of this fuel for the flying model test. The model of a spaceship, able to use laser beam for flying, was small – it weighed 200 g. In laboratory this little ship showed the speed of 3-4 m/s with laser power of 5 kW.
Kizilova Anna