The initiative of Stephen Hawking and Yuri Milner regarding the flight to the Alpha Centauri system may face new difficulties that follow from Einstein's theory of relativity.
The Breakthrough Starshot project, proposed by British theoretical physicist Stephen Hawking and Russian entrepreneur Yuri Milner, involves sending a whole photo of miniature spaceships to the triple star Alpha Centauri, which will be accelerated to 20% of the speed of light using powerful ground lasers. The largest part of the craft will be the sail, where the beam will be directed. Despite the seeming fantasy, the Breakthrough Starshot project is the most realistic way to reach the closest star system to us. The devices will arrive at a distance of 4.36 sv. years to the system approximately 20 years after the start of the mission.
However, the now famous British planetary scientist David M. Kipping has come to the conclusion that the mission will face new, previously unexplored difficulties. The fact is that the properties of matter and light change during the transition to near-light speeds - in this case, they begin to be influenced by the effects that were predicted by Einstein's special theory of relativity. So, the length of the object begins to decrease, and the mass - to increase. All this can negatively affect the work of space "sailing ships".
Relativistic effects will reduce laser power by 10%. So you will need to either increase the latter, or make the laser work longer. But in this case the second problem is aggravated - the heating of the sail. The latter can lead to failure of the electronics, and in addition, part of the laser energy will be spent on heating the environment, i.e., wasted. In addition to all this, once reaching 20% of the speed of light, it becomes difficult to stabilize the beam and it will be more difficult to aim it at the spacecraft.
Kipping himself, however, does not consider these problems insoluble. The creation of new materials in the future may allow the Breakthrough Starshot project to be realized.
Ilya Vedmedenko