This New Propulsion System Will Take A Spacecraft To Alpha Centauri in Just 20 Years

Breakthrough Starshot, an international scientific effort, has revealed their plans to launch a probe to Alpha Centauri, our nearest star system, and it can reach its destination in just 20 years.

Breakthrough Starshot has plans to design and test a new form of spaceship propulsion system that uses a light sail and a laser beam array to achieve the enormous speeds necessary for interstellar travel within our lifetimes, according to a news release from the Australian National University (ANU).

Breakthrough To reach Alpha Centauri, Starshot's ultra-lightweight spaceship will have to travel four light-years. To put it another way, our nearest neighboring star system is 40,208,000,000,000 miles away.

Today's fastest and most dependable long-range space travel technology is the ion thruster, which powers NASA's DART mission to an asteroid at 15,000 mph (24,000 km/h). However, NASA claims that using an ion thruster would take 18,000 years or around 2,700 human generations to reach Alpha Centauri.

However, NASA claims that using an ion thruster would take 18,000 years or around 2,700 human generations to reach Alpha Centauri.

The Breakthrough Starshot team says their spacecraft can fly to Alpha Centauri in under 20 years with the aid of Earth-based lasers. Assuming the probe spacecraft makes it to its goal, it will return the first photographs from another solar system, providing a rare glimpse of faraway worlds similar to Earth.

The ANU researchers described their proposal in a recent research study aiming to make travel to Alpha Centauri viable. The team is building a small probe with a lightsail driven by an Earth laser array. An intergalactic laser array will focus millions of beams on the sail, allowing it to travel at astounding speeds.

In order to go between Alpha Centauri and our own solar system, we need to think outside the box, says Dr. Bandutunga of the ANU Centre for Gravitational Astrophysics' Applied Metrology Laboratories.

"Once on its way, the sail will fly through the vacuum of space for 20 years before reaching its destination. During its flyby of Alpha Centauri, it will record images and scientific measurements which it will broadcast back to Earth."

Breakthrough Starshot and the ANU team rely on the evolution of many important technologies to create their spacecraft. Lightsails, for example, have just lately been demonstrated to be a feasible mode of space travel. LightSail 2, a Carl Sagan-inspired spacecraft, successfully lifted its orbital trajectory around Earth by 3.2 kilometers in 2019 using a lightsail, or solarsail, driven by photons from the Sun.

The key obstacle will be the ANU team's cutting-edge laser array plan, which would require millions of lasers to synch. 

"The Breakthrough Starshot program estimates the total required optical power to be about 100 GW — about 100 times the capacity of the world's largest battery today," Dr. Ward, from the ANU Research School of Physics, says. "To achieve this, we estimate the number of lasers required to be approximately 100 million."

The ANU team suggests employing a 'guide laser' satellite in Earth's orbit to maintain their lasers aiming exactly at the lightsail during the voyage. With an algorithm to pre-correct the array's light, this will accommodate for the atmospheric distortion that the other Earth-bound lasers would endure.

According to Dr. Bandutunga, "the next step is to start testing some of the basic building blocks in a controlled laboratory setting. This includes the concepts for combining small arrays to make larger arrays and the atmospheric correction algorithms." 

As well as being part of a worldwide partnership, the ANU team is only focusing on one aspect of the big project.

Breakthrough Starshot is one of Yuri Milner's Breakthrough Initiatives, a set of scientific and technological efforts aimed at finding life outside our solar system. If the lightsail prototype is successful, it might reach the planets around our closest star, Alpha Centauri, during our lifetime. The project's success would thereby raise humans to the status of interstellar species. 


Breakthrough Starshot

ANU | Scientists lead ambitious study to reach infinity and beyond