Chapter 1: The Allure of the Stars

The cosmos beckons astronomers with its myriad of stars and the profound beauty they embody, enticing us to venture into the vast unknown. Yet, the majority of what we observe lies far beyond our reach.

Among the brightest celestial bodies are Alpha and Beta Centauri, two of the nearest stars to our planet. Historically, the prospect of reaching them seemed far-fetched — until now. Image credit: Zden?k Bardon/ESO.

Our attempts to explore the universe are well-documented. Since the beginning of the space age, we have dispatched probes that have successfully traversed much of our solar system. We have landed on the Moon, observed Jupiter's grandeur up close, navigated through Saturn's rings, and journeyed to the frigid outskirts of interstellar space.

Despite these remarkable achievements, the stars have always remained tantalizingly out of reach, existing primarily in our dreams. Visionaries have proposed various methods to reach Alpha Centauri, the closest star to our solar system. Some envision starships embarking on millennia-long voyages through the cosmos, while others speculate about bending the very fabric of space-time to travel at light speed.

These aspirations may seem impractical for the time being. Even if we were to launch a probe toward Alpha Centauri tomorrow utilizing the latest technological advancements, it would likely become outdated long before it arrived. Other probes powered by futuristic propulsion systems would almost certainly surpass it on its millennium-long journey. It might be wiser to wait for technology to evolve and leave the stars to our imaginations for now.

However, one billionaire holds a different perspective. Yuri Milner is convinced that we stand on the brink of technological breakthroughs that could make nearby stars accessible. So confident is he in this vision that he has allocated a significant portion of his wealth to realize it. His initiative, Breakthrough Starshot, may sound like the fanciful dreams of a wealthy tech mogul, but it is worth considering. Milner has an impressive track record.

Having grown up in the USSR, Milner began his career as a physicist at a prestigious Soviet research institution. Eventually, he shifted his focus to business, first studying at the Wharton School in the U.S. and later working at the World Bank.

During his absence, Russia underwent significant changes. The collapse of the Soviet Union and the end of communism opened new doors for those willing to seize opportunities. Concurrently, America experienced a revolution of its own — the rise of the Internet. Upon returning to Russia, Milner saw his future intertwined with both revolutions.

A decade and several successful startups later, Milner returned to the U.S. as a wealthy individual. He made significant investments in emerging companies like Facebook and GroupOn, further increasing his fortune. This newfound wealth enabled him to pursue his passion for fundamental science, culminating in the establishment of the Breakthrough Prize in 2012, which rewards groundbreaking research.

Unlike the formal ceremonies of the Nobel Prize, the Breakthrough Prize events resemble glamorous Hollywood galas, attracting numerous billionaires and celebrities. With millions of dollars in awards, they have become some of the most prestigious scientific recognitions globally.

Three years after launching the Breakthrough Prize, Milner initiated the Breakthrough Initiatives. This project, featuring notable figures like Stephen Hawking, introduced three programs: Listen, Message, and Starshot, all focusing on humanity's role in the universe.

The Listen and Message programs concentrate on searching for signs of extraterrestrial civilizations and establishing contact with them. As part of Breakthrough Listen, Milner has invested $100 million in new astronomical observatories designed to detect alien signals, akin to previous SETI efforts.

Traditional searches for alien signals have primarily focused on identifying deliberate radio transmissions from extraterrestrial sources. However, this method faces numerous challenges. For instance, the vastness of space means signals could originate from any direction, transmitted on any frequency at any time, making serendipitous discovery exceedingly unlikely. Despite decades of searching, no verified alien signal has been detected.

To address these challenges, Breakthrough Listen has adopted a novel approach. Rather than solely relying on radio waves, the initiative is also examining laser signals that an advanced civilization might favor for communication. The project aims to capture non-deliberate signals, such as flashes from spacecraft engines or signs of large-scale engineering projects that may reshape entire solar systems.

Two recent phenomena have piqued the interest of those searching for extraterrestrial life: unusual light patterns from Boyajian's Star and the brief appearance of Oumuamua, an interstellar asteroid passing through our solar system. Breakthrough Listen allocated resources to investigate both occurrences, focusing on potential artificial signals, either laser-based or radio. Thus far, no significant findings have emerged, but Milner is already preparing for the next extraordinary discovery.

With this impressive background, Milner's ambitions to explore the stars seem less far-fetched. Nonetheless, the scale of his aspirations is undeniably impressive. Starshot, the third component of the Breakthrough Initiatives, aims to achieve nothing less than interstellar travel.

Milner's strategy involves creating a fleet of miniature spacecraft, each measuring less than an inch in size and weighing only a few ounces. These probes would be propelled by powerful lasers to one-fifth the speed of light, allowing access to a dozen stars within a 50-year journey from Earth.

The small size of the proposed spacecraft is crucial. Lightweight probes require significantly less time and energy to accelerate to high speeds, making them more cost-effective to produce. In theory, Milner could manufacture thousands of these tiny spacecraft for the price of a conventional Mars-bound probe.

This mass production is essential because high-speed interstellar travel poses considerable risks. At nearly the speed of light, even a collision with a tiny speck of dust could result in catastrophic damage. By deploying a sufficiently large fleet, Breakthrough Starshot hopes that at least one probe will survive the journey.

Typically, spacecraft must carry hefty fuel supplies, as opportunities for refueling in space are limited. Thus, probes need to ensure they possess enough fuel before launch. This presents a challenge for nanoships, which can only carry minimal fuel. Instead, Milner proposes equipping them with solar sails that harness sunlight as a power source.

A solar sail functions as a large reflective surface. Once placed in space, it gradually moves away from the Sun due to the pressure exerted by sunlight bouncing off its surface. While several experimental missions have successfully demonstrated this concept, the force of sunlight is relatively weak, limiting practical applications.

Milner's vision is to replace sunlight with much more powerful lasers. Studies suggest that sails a few feet in size could achieve speeds of up to one-fifth the speed of light when powered by intense lasers. Additionally, these solar sails could double as antennas for transmitting signals back to Earth.

While this concept appears feasible in theory, much of the necessary technology is still under development. Significant advancements are needed in areas such as solar sails, communication systems, laser technology, and miniaturization.

Even if the technology is viable, the engineering challenges are monumental. The lasers required to propel the nanoships would be the largest ever constructed, each requiring its own power station and consuming as much electricity as a small city.

The obstacles do not end there. The sails must be exceptionally reflective; otherwise, the intense laser beams could vaporize the small crafts. Currently, we lack materials capable of achieving this, and our understanding of physics is insufficient to determine if such materials can even exist.

The powerful lasers pose another concern. If built, these intense lasers could become dangerous weapons, capable of devastating entire cities. It is inevitable that military powers would monitor them closely. If such technology were to fall into the wrong hands, the consequences could be catastrophic.

These issues are largely challenges for the future. Milner's primary goal is to stimulate research and inspire innovative thinkers to explore what might be achievable. To this end, he is contemplating additional exploration projects that could yield valuable data.

One area of interest is the various water worlds discovered in the outer Solar System in recent years. Scientists speculate that some of these celestial bodies, particularly Europa and Enceladus, may harbor primitive life forms. Historically, missions to these locations have been funded by national agencies like NASA or ESA. Milner believes he can personally finance a cost-effective scientific mission to one of these worlds, potentially Enceladus.

This type of mission exemplifies the real benefits of Breakthrough Starshot. Even if the science and engineering required to propel tiny spacecraft to nearby stars prove impractical, the technology could be adapted for more feasible missions. Smaller lasers and less sophisticated probes might be utilized to explore the outer solar system. Currently, reaching distant planets like Neptune can take decades, but laser-powered solar sails could significantly reduce travel times.

The landscape of space exploration is already evolving. Space agencies are developing a new generation of missions that utilize smaller satellites. Could the next phase witness a full embrace of miniaturization? Might we soon populate the solar system with fleets of laser-powered nanoships? If this comes to pass, we may gain unprecedented insights into our neighboring worlds, and perhaps, just perhaps, uncover signs of extraterrestrial life.

The first video, "TANGERINE DREAM - Alpha Centauri [1971] - YouTube," provides an auditory journey through space, evoking the mystery and allure of the stars, reminiscent of our quest for Alpha Centauri.

The second video, "Warp Drive to Alpha Centauri - Lucid Dreaming Space Music - YouTube," takes viewers on an ethereal journey through space, blending music with visuals to inspire thoughts of exploration beyond our solar system.