This is how humans might finally reach another star system.
Beeld: Breakthrough Starshot
Last year, Russian billionaire Yuri Milner and physicist Stephen Hawking announced the Breakthrough Starshot initiative, a $100 million program to develop technologies for small robotic nanoprobes and light beams with the power to accelerate to 20 percent of the speed of light—fast enough to reach the nearest star system within a generation. When Breakthrough Starshot was first announced, even Facebook's co-founder and CEO Mark Zuckerberg joined the exciting project and became a member of the board.
The goal is to accelerate these ultralight nanocrafts, which are about the size of a postage stamp, to speeds up to 100 million miles an hour. At that velocity, they'll have the capability to reach the neighboring star system Alpha Centauri (located about four light years for Earth) relatively quickly. There, these tiny space probes could reach Proxima b, the closest known Earth-like exoplanet, about 20 years after they're launched.
One day, these miniature spacecraft should also carry astronauts.
- A centimeter-scale space probe on a wafer dubbed StarChip, with cameras, photon thrusters, power supply, navigation, and communication equipment;
- A meter-scale lightsail that propels the StarChip forward; and
- A light beamer, with an array of high-power (100 gigawatt) lasers, capable of accelerating a StarChip and its lightsail—both weighing only a few grams—to 20 percent the speed of light.
There is no room for a deceleration system, so the mission would be a high-speed flyby with the goal of returning data and images. (The spacecraft would never return to Earth.)
Every element of the Starshot system presents significant engineering challenges. Keeping the lightsail intact and the advanced automation needed to self-operate the probes without time lag are just a few. These and other challenges are explored by engineers and citizen scientists on the Breakthrough website. Though clearly a momentous task, building the Starshot system is conservatively estimated to be feasible within a few decades.
"The beauty of the Starshot initiative is that it works on an inspirational, tough, but likely doable engineering problem where we are unlikely to have to invent an entirely new technology," Anders Sandberg, a researcher at Oxford University's Future of Humanity Institute (FHI) told me in an email. "[Surprises] may well come in the next decades and could change what we can and want to achieve with the Starshot, but even the most basic version would transform our place in the universe from a single solar system species to one that is reaching out and touching other stars."
Earlier this year, a number of prototype "Sprites"—the world's smallest fully functional space probes built on a single circuit board—were deployed in low Earth orbit. These Sprites provided the first proof of concept for highly miniaturized spacecraft, and are a stepping stone toward StarChips.
The Breakthrough Starshot initiative has been endowed by Milner with $100 million initial funding, which is significantly more than most visionary science projects receive, and will support top class research, prototyping work, and small scale pilot projects.
But a mere $100 million is hardly sufficient to see the project through. Milner's estimate for the total cost of Breakthrough Starshot is $5-10 billion, which is a typical order of magnitude for large-scale global science projects such as the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN). Just like the LHC was built and is now operational, Starshot could one day be launched and used to send images back from the stars, as long as it receives enough funding.
Images of what, exactly? The recently discovered exoplanet Proxima b, which orbits the red dwarf Proxima Centauri in the three-star Alpha Centauri system, has been chosen as the primary target of the first Starshot interstellar mission. Breakthrough Initiatives is now funding European Southern Observatory (ESO)'s campaign to search for other planets near Alpha Centauri.
Proxima b or other nearby planets could be—or could be made—habitable, and may become a second home for a spacefaring humanity expanding to the stars. "Our ingenuity will get us to Proxima b," Stephen Hawking told BBC. "Colonising Proxima b will challenge our species like nothing before."
Our first trip to the stars may be made by highly miniaturized robotic probes equipped with the best our planet can produce. Too bad the nanoprobes themselves, while able to capture images and data, will be dumb, unthinking, and unfeeling hardware. Or will they? Perhaps the universe deserves thinking and feeling ambassadors.
It seems likely that the first swarms of Starshot probes would—at the earliest—be launched well into the second half of the century. By that time, we may have have operational implementations, or at least research prototypes, of:
- Sentient, human-like Artificial Intelligence;
- Human mind uploads, and;
- Powerful nanocomputers and/or quantum computers able to run consciousness within the size, weight, and power of a StarChip (or a swarm of StarChips).
Therefore, it might be possible to send the first sentient ambassadors (AIs, uploads, or hybrids) to the stars.
The first two possibilities—AI and uploads—are linked. In fact, sentient AIs will likely be based on generic "mindware" able to support human-like consciousness. Mindware will permit building a new conscious AI from scratch, or a software personality modeled after a specific human being, which (or, better, who) thinks and feels like a continuation of the original.
The emulation of a specific person could be achieved by augmenting the underlying mindware with personalized data acquired by scanning the person's brain, or by training the mindware until it behaves like the original, which is the "sideloading" technique described by writer Greg Egan in the science fiction novel Zendegi. Given current trends in miniaturization and quantum computing, the third requirement—availability of suitable hardware—seems likely to be achieved before the end of the century.
In the future, we won't need to send wetware human bodies to the stars, because we'll be able to send software minds. I am persuaded that it's up to our post-biological descendants to colonize the universe. In the meantime, of course, we need to go on with "old fashioned" space exploration to stay energetic and mentally healthy as a species. It would be great if flesh-and-blood humans spread to other planets in this century, but then, the first Starshot launch could mark the beginning of our transition to post-biological life.
Sandberg, the Oxford researcher, who co-authored FHI's seminal "Whole Brain Emulation Roadmap" (2008), is cautiously optimistic. "Making timing estimates for future technology is hard: the order of arrival of advanced low-power computing, AI, brain emulations, atomically precise manufacturing, and a working Starshot could be arbitrary," he said. "So we might end up with constellations of dumb chips (still tremendously useful), very capable probes that can plan and act on their own, or even posthuman ambassadors. But we do not know which yet."
Time will tell. If all required technologies materialize in this century, I would certainly volunteer for a copy of my mind to be sent to the stars on the first Starshot mission. I'm sure I would have good company, because many people want to go. Billionaire space and biotech entrepreneur Martine Rothblatt made a bold proposal: Let's just invite everyone onboard the first starship.
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