The ambitious Breakthrough Starshot initiative has revealed its groundbreaking plan to explore Alpha Centauri, our nearest star system, using an innovative spacecraft propulsion method. The project aims to develop a tiny probe attached to a lightsail powered by a laser array located on Earth. If successful, this spacecraft could traverse the 40 trillion kilometers to Alpha Centauri in just 20 years—an incredible leap compared to current technologies.

The ANU team, a key partner in this international effort, detailed the concept in a recent research paper. The lightsail would harness millions of high-powered laser beams focused on it, propelling the lightweight probe to unprecedented speeds. For comparison, NASA’s ion thruster—the fastest existing propulsion system—would take around 18,000 years to cover the same distance.

Achieving this bold vision requires advancing multiple technologies. Lightsails, a propulsion system driven by photons, have already shown promise. For example, the LightSail 2 project in 2019 successfully raised its orbit around Earth by 3.2 kilometers using sunlight. Breakthrough Starshot aims to take this further by leveraging a laser array with an estimated power of 100 GW, 100 times greater than the capacity of the world’s largest battery.

Precision is critical. To ensure the laser array accurately focuses on the lightsail during the journey, the ANU team proposes using a ‘guide laser’ satellite in orbit. This satellite will coordinate millions of lasers on Earth, supported by advanced algorithms to correct for atmospheric distortions. According to Dr. Robert Ward of the ANU Research School of Physics, the system requires around 100 million lasers to generate the necessary power.

Once launched, the probe will travel for 20 years before reaching Alpha Centauri. During its brief flyby, it will capture images and gather data on planets within the system, transmitting this information back to Earth.

Breakthrough Starshot is one of the Breakthrough Initiatives, a suite of programs founded by Yuri Milner to advance space exploration and the search for extraterrestrial life. The ANU team emphasizes that their role focuses on laser array development, while other global collaborators contribute to different aspects of the mission.

If successful, this project would mark humanity’s first step toward interstellar travel. The ability to send a probe to another star system could redefine our understanding of the universe and elevate humans to an interstellar species. The dream of exploring distant worlds and discovering whether life exists beyond Earth might soon become a reality.