A team at California Institute of Technology the researchers of implementing the Breakthrough Starshot project.
In the Perspective article published in the journal Nature Materials, researchers outlined the obstacles and possible solutions that project engineers still face.
Breakthrough Starshot was a project initiated by supporter Yuri Milner two years ago – its goal was to send spacecraft from the solar system to Alpha Centauri before the middle of this century.
Most of these spacecraft designs revolve around the idea of light sails and micro-devices to communicate.
The process will be powered by a laser array located on the earth. In order to reach the Alpha Centaur in a reasonable amount of time, the aircraft will need to travel at a very fast speed, approaching 20% of the speed of light.
After all, Alpha Centauri is 4.37 light years away. Although this concept is relatively simple, the design poses a severe challenge, as the team emphasizes.
The $100 million breakthrough Starshot program announced in 2016 plans to use powerful lasers to launch a series of small spacecraft to our own recent star system, Alpha Centauri.
Although the use of laser cannons to propel spacecraft may sound like science fiction, previous studies have shown that “light sailboats” may be one of the only technically feasible methods to explore another star in human life.
The researchers pointed out that due to the momentum carried by the photons, the light beam can be pushed by the laser beam.
But in order to work, sails must be reflective. It must also be very thin (perhaps just a few atoms), light weight, and less than a gram.
So far, engineers have seen graphene, but it is not reflective, which means it needs a certain kind of coating. On the other hand, reflective materials such as metal are too heavy. The research team reported that no suitable material has been found yet.
Another challenge the team will face is how to maintain the stability and focus of multiple laser beams while passing through the Earth’s atmosphere.
This may mean using a low-near-infrared beam, which means that the sail must be able to reflect this wavelength of light. But subsequent weight and fever problems will work.
The team pointed out that these issues mean that engineers must balance many factors in order to find the right combination of materials.
The team had to consider the shape of the sail – it couldn’t be a simple flat plate because its surface flaws would bring the craft to space. Instead, engineers will have to develop a design that allows self-correction.