Scientists at the Australian National University have proposed a way to launch a space sailing ship to the nearest star as part of the Breakthrough Starshot project. According to their idea, the photon engine – a system that in total includes up to 100 million lasers – will help to give the device the necessary speed. Their calculations, researchers reported in the Journal of the Optical Society of America.
The Breakthrough Starshot project is a Breakthrough Initiatives project aiming to prove the possibility of interstellar flight in a single generation. For this, the concept of the space sailing ship ‘StarChip’ was chosen.
In it, a nanoprobe measuring 3.5 by 3.5 centimeters and weighing about a gram, equipped with sensors, a camera, a radio antenna and accelerators, will be connected to a solar sail measuring four by four meters, 100 nanometers thick and weighing one gram.
The idea of such a sail was theoretically substantiated by one of the pioneers of rocketry, Friedrich Zander. Such devices already exist: in 2010, the Japanese IKAROS was launched , the United States sent LightSail-1 and LightSail-2 into space.
Now Australian scientists have proposed a way to accelerate the space sailing ship from geostationary orbit using a giant network of laser systems.
“The Breakthrough Starshot program assumes that the required optical power, for the device to gain the required speed, is about 100 gigawatts,” Robert Ward, one of the researchers said.
It will not be easy to come close to such numbers, he said – currently, the largest batteries have 100 times less energy.
Each complex will consist of a thousand sectors with a thousand modules, each of which will have 100 lasers. Each of these lasers with a wavelength of 1064 nanometers will emit a kilowatt of optical energy.
According to preliminary estimates made earlier, the cost of such a system could reach eight billion dollars, and the cost of the acceleration operation itself – about six.
However, when operating such a laser facility, it is necessary to take into account the influence of the earth’s atmosphere.
“The atmosphere distorts the outgoing laser beam, causing it to deviate from the desired direction,” another researcher, Professor Michael Ireland said. – Our solution involves the use of a laser guide star. In it, a small satellite will direct a laser to the array from Earth’s orbit. As the light from the guide star travels towards Earth, it will help measure atmospheric-induced distortion. We have developed an algorithm that will allow us to use this information for early adjustments.”
In addition, it is necessary to take into account the deflection of the laser beams themselves.
“We use a random digital signal to encode the measurements of each of the lasers and then decode them. This allows us to choose from a huge pile of information only those dimensions that we need. Then we can narrow the problem down to small complexes,” Paul Sibley said, another member of the research group.
Traveling to Alpha Centauri using conventional travel methods will take about 100 years. Getting to Alpha Centauri using a space sailboat powered by a photon engine is expected to take 20 years at a speed of 20% of light.
“During the flyby of Alpha Centauri, the sailboat will take pictures and take measurements, which will then be transmitted to Earth,” the lead author of the study, Chatura Bandutunga, said.
It is assumed that five years after the measurements, astronomers will receive data on the satellite of Proxima Centauri – Proxima Centauri b, as well as other exoplanets in the system, if they are detected.
However, scientists emphasize, their development, like the sailboat itself, is still only a concept.
“Despite the fact that we are confident in the design of our development, it has yet to be tested. The next step will be to test the main structural elements in a controlled laboratory environment. Among them are concepts for combining small laser systems and algorithms for atmospheric correction,” Bandutunga said.
