Well, that didn’t take as long we thought.
A concept I first heard introduced at the 100-Year Starship symposium last fall proposed a stream of postage stamp-sized probes with light sails propelled by a 10-minute burst of laser beams that accelerates the probes to 20 percent light speed. At that speed, the probes could reach Alpha Centauri in 20 years. It was the only proposal presented on star travel at the symposium that didn’t violate known physics, take multiple generations to reach the stars, or require exotic forms of energy that may or may not exist. It was an intriguing plan for those involved with 100 YSS, an organization that still had 96 years to find the technology to reach the stars.
Dr. Philip Lubin, professor of physics at the University of California Santa Barbara, did have one major hurdle to clear before we started sending his WaferSats to Alpha Centauri and beyond. While the basic technology already exists, it was going to take a great deal of development and a massive amount of funding to build the 100-gigawatt phased-laser array needed to send the tiny probes on their way.
Then last week, a trio of big names in philanthropy, cosmology and social media announced Breakthrough Starshot. The bold plan is a $100 million research and engineering program (which comes to about $1 for each mile per hour of the WaferSats velocity) to begin on the road map that Lubin laid out to reach the stars. There’s still plenty of work to do and even more money to spend to make Starshot a reality.
But until the announcement, no one was sure we had a realistic chance of reaching 100 years within 100 years. Now we have a viable plan that sends multiple, albeit tiny, probes to the nearest stars and send information back to us in about 45 years – 20 years to develop and build the system, 20 years to get to Alpha Centauri, and 4.4 years for the probes’ data to get back to Earth. If the timeline holds, that’s 41 years ahead of 100 YSS’ schedule.
Big money for a big ideas
Lubin last year made the round of several science seminars and conventions besides the 100 YSS symposium, and received a reasonable amount of press for the ideas he presented. Yet when Breakthrough Starshot was announced last week, none of the news articles I read about it even mentioned Lubin.
Instead, the press reported Starshot as an idea created by two of the project’s star-studded board of directors who announced the project: Russian philanthropist and Internet entrepreneur Yuri Milner, and cosmologist Stephen Hawking. They’ll be joined on the board by Facebook founder Mark Zuckerberg.
The sudden glare of the spotlight on the stars with deep pockets and name recognition, while leaving in the shadows Lubin and other researchers who did the grunt work in developing the concept, reads much like the plot from the late Carl Sagan’s novel and subsequent movie, Contact. It’s a somewhat ironic twist since Jill Tarter, a pioneer in SETI research and a member of the management and advisory committee for Breakthrough Starshot, is said to be Sagan’s model for his novel’s lead character.
While the news articles seemed to miss Lubin, he was on the stage in New York for the StarShot announcement. Dig deeper on the breakthroughinitiatives.org website and you do find Lubin’s name serving on the same StarShot committee as Tarter. His paper, “A Roadmap to Interstellar Flight,” is also the lead listing in Starshot’s research web page. But as is typical for the news media, it reported on the names the reporters and the public knows.
It happens. Give credit to Lubin and fellow researchers at UCSB for coming up with the idea and the plan to make it work in the first place. But if their concept was ever to become reality, Lubin had to make the rounds of science conferences, putting the roadmap for sending the wafer-sized explorers in a position to be noticed by people with money and vision.
Give credit to Milner, Hawking and Zuckerberg for recognizing the importance and potential of the work by Lubin and fellow researchers, and to provide enough seed money to get the project off the ground. But it appears the only new ideas revealed during last week’s announcement was a much cooler name for Lubin’s “WaverSats,” now to be called “StarChips,” and the placement of that 100-gigawatt laser array on Earth rather than in Earth orbit as Lubin initially described his roadmap.
Watch where you point that thing
Placing the laser array on Earth, however, seems a questionable idea, though it resolves a significant issue. The laser array would be a permanent structure that could be used repeatedly to send the StarChips on five-year missions or longer to Alpha Centauri and other stars, while spending probes and even crewed ships to Mars over much shorter times than can be accomplished now (though getting them back would require another laser array at Mars, I would think).
The laser array can even be used for planetary defense against errant asteroids on a collision course with us. That’s undoubtedly useful for a population not anxious to follow the way of the dinosaurs, but it also shows the problem of a 10-gigawatt laser stationed in Earth orbit. It can be turned around to incinerate a suspected terrorist base, destroy a North Korean missile launch site, or raze the capital of a country we just don’t like.
While the laser array would likely be run by an international scientific consortium, that doesn’t exempt it from international treaties banning weapons of mass destruction in orbit. Operation Starshot’s answer is to build the laser array in the dry, mountain desert of Chile. But even in the thin air of the Andes Mountains, atmospheric interference can make the laser beams less effective. Placing it in on the planet also limits its targeting capabilities, a good thing for anyone who fears they may become one of those targets, not so good if you want to explore the Solar System and the Milky Way.
When I heard Lubin talk in fall, several attendees raised the treaty violation issue, but suggested the array be parked at the Lagrange point above the far side of the moon, L2. In that way, the Moon lies constantly between the lasers and any theoretical target on Earth. It also seems plausible to build the array on the Moon’s surface, again on the far side. Either way, such positioning wold seem to increase the laser’s efficiency in space exploration while eliminating its use as a weapon, except for defending against marauding asteroids.
If Breaktrhough Starshot keeps to its timetable, its researchers and engineers still have 20 years or so to decide where to put the phased laser array. We already know where the StarChips are going.