As part of the Breakthrough Starshot project, researchers tried to improve the design of a galaxy photonic sail. For this, they had to take into account the barrier of photonic pressure in the structure and the possibility of a tear in the boat. Such photonic sails would propel the spacecraft to 20% faster than the speed of light, traveling at about 20 years (instead of several thousand years) to Alpha Centauri (the nearest star and planetary system).
The idea of propelling itself into space using a light-guided boat is not new. Breakthrough Starshot Project The ambition was already to send small ships (driven by photowheeling) to nearby stars, but more research was needed to understand how to sustain these models throughout the voyage.
While the choice may seem surprising, the use of photon shocks and light-reflecting boats may be the only chance to reach another star in human life. Thanks to the thin material of a few nanometers and the array of powerful lasers, the sails make it possible to carry the spacecraft (20% of the speed of light) to the alpha centauri (alpha centauri, star system and planet). In about twenty years (instead of several thousand years).
Designing static objects
” Reaching another star in our lifetime will require a relative speed, i.e. a speed close to the speed of light “, To explain In a press release Igor Barkatin is a mechanical engineer and professor of research at the University of Pennsylvania. As part of the project, his team works on the design of the boat’s materials, its size and its shape, in order to find a sustainable solution before it is planned in space.
Other research suggests that the sun may provide all the energy needed to move light boats. But the intensity of the light must be very high to achieve the relative speed induced by burgundy. To capture more light, one can increase the size of the boat or direct a greater number of ground rays towards it. But in the first case, the weight of the boat will be heavier, so it will be more difficult to move; And by reducing the mass of the sail, it becomes less strong and more tearable.
Two studies published in the journal Nano letters Describe the basic properties of sails to be fabricated from very thin sheets of aluminum oxide and molybdenum disulfide.
First study: Obtaining the curve of a parachute
In the first paper, researchers point out that light boats. who Are rapidly accelerated to relative speeds by lasers and must be bent dramatically [et non plates comme supposé précédemment] To reduce their mechanical stresses and to avoid tearing “.
” The implication here is that the thinner the sail, the more likely it is to tear, whether in a sailing boat or in space. , Barclays explains. ” It is a relatively easy concept to understand, but we had to do some complex calculations to show how these products work on this scale. “.
Second study: withstands thermal stress
The second study is led by Ashwat Raman, an assistant professor in the Department of Materials Science and Engineering at UCLA. It provides insight into how nanoscale shapes inside a boat can scatter heat scattered by a laser beam a million times more powerful than the sun (based on the light emitted, which is much denser in the case of a laser). Thermal management is the main goal of photonic sail design because it requires intense laser forces, but is often considered secondary to acceleration performance.
” If the sails absorb even a small fraction of the laser light, they will reach very high temperatures. “Says Raman.” To ensure that they do not rot, they must increase their heat radiation capacity, which is the only heat transfer mode available in space. “.
The newly discovered optical properties allow a good balance between the minimum absorption and emission of light. The sail will withstand even stronger initial momentum, reducing the time it takes for the lasers to stay at their target.
” A few years ago, thinking or doing theoretical work in this kind of concept was considered far-fetched. Professor Deep Jariwala concludes. ” Today, we have an opinion, but this opinion is based on real materials available in our labs. Our plan for the future is to develop such structures on a small scale and test them with high-powered lasers. “.