A Russian billionaire named Yuri Milner wants to send a probe to Alpha Centauri, the nearest star system to earth. Given the crazy distance involved – Alpha Centauri is 4.37 light-years away, or 25 trillion miles – the probe would have to travel at a significant fraction of the speed of light in order to reach its destination within our lifetimes. Even traveling at 20% of the speed of light, the probe would take over 20 years to get there, and then another 4.37 years to transmit any data back to earth.
Pulling this off would require a series of technological and engineering breakthroughs, though it wouldn’t violate any known laws of physics. Milner’s team has proposed building a tiny computer chip attached to a thin reflective sail, called a light sail, that would catch the energy from a giant array of ground-based lasers to speed to its destination. Here is a good overview of the project, announced last April, and its many challenges:
Given all these hurdles, what are the odds of success? Technologically savvy people not connected to Starshot estimate they are small; several people told me flatly, “They’re not going to Alpha Centauri.” David Charbonneau of the Harvard-Smithsonian Center for Astrophysics says the project will ultimately be so expensive that “it may amount to convincing the U.S. population to put 5 percent of the national budget—the same fraction as the Apollo program—into it.”
I think it’s an awesome initiative, but in ways that are mostly hard to explain. It’s going to be tough to convince the public to get behind a project that, if successful, would take an entire generation to send us some cruddy, low-res photos of a star. A manned mission to Mars might be easier to sell, even if it turns out to be much more expensive.
However, Milner’s project is privately funded – for now. And I hope he succeeds because… interstellar probe, man.