Laser Sails Could Reach Alpha Centauri in 20 Years

Using new technology created by researchers at the Rochester Institute of Technology in New York, a spacecraft would be able to be launched to the closest star, Alpha Centauri, which is 437 light-years away.

Chemical reactions are used to propel standard rockets. However, the bigger the rocket is, the more propellant it needs, making the spacecraft heavy and inefficient. For long trips, this is a waste of money and resources. In 1977, NASA launched the Voyager 1 Spacecraft into interstellar space, which it reached 25 years later. If Voyager 1 had been launched to Alpha Centauri, it would have arrived there in 75,000 years. 

In 2016, a $100 million Breakthrough Starshot initiative was announced. The plan is to reach Alpha Centauri in a human lifetime by launching swarms of microchip-size spacecraft. The researchers say that they are able to make this invention through “light sailing” using the most powerful lasers ever built. This is most likely the only way to reach a star in a human lifetime. 

The plan says that the laser sails could reach Alpha Centauri in 20 years, which means that the spacecraft would be flying at about 20 percent of the speed of light. Studies have proved that light can exert pressure. If they use a big enough mirror and a lightweight spacecraft, light can be used as propulsion for “solar sails.” 

Researchers built the sails using the diffraction grating structure, which is mainly used for CDs and DVDs. A grating structure is made up of microscopic slits that are able to diffract light. 

They were able to line up liquid crystals in each grating contained in a plastic sheet. The sail is built out of two diffractive gratings placed side by side. The liquid crystals used are similar to the displays of electronic screens. These liquid crystals deflect light rays at an angle, making the sail go backward and sideways. The left side of the sail’s grating deflects light to the right side, and vice versa. This method is used so the light can be put back in the center if the sail falls to either side.

This breakthrough invention has impacted space travel and will be able to broaden scientists’ knowledge of space. The sails are going to be tested first on the International Space Station or a small satellite. 



I love learning new things. good job Devika!! – Desteny AlvarezMonona Grove High School (2020-06-04 14:36)
This is really interesting. Good work, Devika!! – Shoko MiyagiUW-Madison (2020-07-12 17:52)