NASA has announced that it is participating in an effort initiated by British astrophysicist Professor Stephen Hawking and venture capitalist Yuri Milner to build a tiny spacecraft or nanocraft that can reach Alpha Centauri — the nearest star system to Earth — in 20 years, traveling at about one-fifth the speed of light.
Breakthrough Starshot, a plan to build a fleet of self-repairing spacecraft to find a new habitable planet for humanity, was initiated by a team of scientists, including Stephen Hawking.
Hawking’s participation in Breakthrough Starshot is informed by a view he has stated publicly on multiple occasions — that humanity has only about a thousand years left to find a new habitable planet before we destroy Earth.
The team of scientists hopes to be able to launch a tiny “StarChip” to planet Proxima b, a rocky Earth-like exoplanet orbiting in the habitable zone of our Sun’s closest stellar neighbor, the dwarf star Proxima Centauri, about 4.22 light years away.
Proxima b was discovered in August by the European Southern Observatory (ESO) using NASA’s Kepler Telescope. Its parent star, the dwarf star Proxima Centauri, is part of the star system Alpha Centauri, consisting of two other stars, Alpha Centauri A and Alpha Centauri B, about 4.22 light years away.
Although Proxima b is nearer to its parent star Proxima Centauri than the Earth is to the Sun, it still lies in the “Goldilocks” or “habitable zone” of its star, where temperatures are neither too hot nor too cold for life-supporting liquid water and other conditions necessary for life as we know it on Earth to thrive.
The team of scientists involved in Breakthrough Starshot plan to reach the Proxima Centauri system within 20 years by accelerating their tiny “StarChip” to one-fifth (20 percent) of the speed of light. They plan to achieve the incredible speed by shooting lasers at the nanocraft from beamers located on Earth.
The scientists hope that successful launch of a tiny probe to our nearest star system would pave the way for the launch of a fleet of spacecraft to search other nearby star systems for habitable planets. They hope that the fleet of spacecraft will find an atmosphere potentially capable of supporting human settlers on Proxima b or elsewhere.
“If further research concludes that the conditions of its [Proxima b] atmosphere are suitable to support life, this is arguably one of the most important scientific discoveries we will ever make,” commented Dr John Barnes in a study published in the journal Nature.
NASA’s participation in Breakthrough Starshot is to help solve one of the major problems facing the project: how to protect the spacecraft from the intense cosmic radiation it will encounter during interstellar flight.
According to scientists, an ordinary spacecraft could not survive damaging cosmic radiation during a 4.37 light-year journey (25 trillion miles) that could take up to 30 years.
The obvious solution to the problem is to provide adequate radiation shielding for the sensitive electronic components of the spacecraft. However, the approach is not feasible because the plan to accelerate the spacecraft to 134 million mph — about 1,000 times faster than an ordinary spacecraft — means that it has to be a very lightweight nanocraft.
Radiation shielding would involve using heavy materials that add significantly to the size and weight of the craft and slow down the speed of the craft.
Another suggestion, one of several presented at the International Electron Devices Meeting in San Francisco last week, would involve charting a course to Alpha Centauri that avoids high-radiation space regions. But experts rejected the suggestion, pointing out that the best route possible would still not reduce overall radiation exposure sufficiently to prevent damage to the craft. It would only add years to the voyage.
NASA and researchers from the Korea Institute of Science and Technology (KAIST) eventually suggested equipping the spacecraft with “self-healing” transistors or silicon chips, according to Engadget.
After researchers at KAIST conducted preliminary tests using lightweight nanowire transistors with the capability to self-repair following radiation damage, they recommended the suggestion as a possible way to overcome the problem of damaging interstellar radiation.
However, a lot of research and development is still needed to demonstrate the feasibly of the plan conclusively. But scientists are optimistic that it is the best and most promising option available.
“Today, we commit to this next great leap into the cosmos because we are human, and our nature is to fly.”
“The limit that confronts us now is the great void between us and the stars. But now we can transcend it,” Hawking said when project Breakthrough StarShot was first announced in April. “With light beams, light sails, and the lightest spacecraft ever built, we can launch a mission to Alpha Centauri within a generation.”
[Featured image by Dennis Van Tine/STAR MAX/AP Images]