Theoretical physics legend Stephen Hawking and Russian billionaire entrepreneur Yuri Milner propose tiny spaceships are our closest celestial neighbors.
People like to travel and explore. From walking on the Silk Road to sailing through the New World to flying through the air from Tokyo to San Francisco, people have enjoyed going to distant lands. Currently, the most distant land lies in outer space.
Arguably the only reason that we haven’t casually explored space yet is because it’s simply too hard. The vacuum of space isn’t very accommodating to life, the distances between destinations are astronomical and we don’t have the technology to overcome these hurdles easily (yet).
Still, we’ve managed to send countless satellites into orbit around the planet, human beings into the space station and numerous probes to the farthest reaches of our solar system, such as Voyager 1, which actually left the solar system.
These probes are rather large and cumbersome, the most recognizable ones (Voyager 1, Cassini, Pioneer 10, etc.) being in the 800-2400 kilogram range, and anywhere from 3 meters (9.84 feet) to 7 meters (22.97 feet) in length. Because of this, they are very costly to create, launch and maintain. While science fiction often depicts massive spaceships, Hawking and Milner propose going in the other direction: tiny spaceships.
Their idea — called Breakthrough Starshot — was conceived as a means to discover extraterrestrial life. The project focuses on using a series of laser arrays to propel a fleet of nano-spacecraft, no more than the size of a postage stamp, accelerating it to nearly 20 percent the speed of light with the goal of reaching Alpha Centauri, the closest star system to our own solar system.
The nano-craft, dubbed “Starchips,” would be attached to a large “solar sail,” which the Earth-mounted laser would then hit and accelerate through the power of light energy.
One of our faster spacecraft flies at 33,000 miles per hour, which means that it would take 20,000 years to reach Alpha Centauri. With these “Starchips” and new method of propulsion, the same journey can be done in 20 years. According to Hawking, “The limit that confronts us now is the great void between us and the stars, but now we can transcend it.”
Hawking and Milner have faith in this project for many reasons. For one, the nano-crafts are relatively cheap. While technology still has a way to go, the cost to launch each “Starchip” would be in the $100,000 range. For comparison, sending a space shuttle up costs at least $450 million, almost 1,000 times more expensive. They also believe in Moore’s Law, which states that computer power doubles every two years and can be reduced in size.
Of course, the idea has been met with skepticism. The total power of the laser array is roughly 100 gigawatts, which is equivalent to the amount of power the entire country of France consumed in 2012. This kind of power could fry anything in its path, such as an orbiting satellite.
Secondly, while the Starchips themselves will optimally only cost in the hundred thousands, the entire process, from announcement to launch, is expensive. Milner donated $100 million, but that is only a fraction of the cost it took to send New Horizons out to Pluto ($722 million).
There’s also the matter of time. Even though light is the fastest speed possible (known to us), it would still take a long time for signals to go back and forth between the probe and Earth. Assuming the Starchip probe can reach one lightyear of distance, if it runs into a problem it will take one year for that error message to reach Earth and another year for our scientists to beam a message back. By then, either the problem will have passed or the probe will have been destroyed.
“The propulsion thing is cool and all, but this is, I think, the fourth time these two have proposed something and nothing came out of the other three times,” Fletcher Porter, first-year mechanical engineering major, commented. “We haven’t seen anything remotely indicating signs of life at Alpha Centauri, so I don’t think that sending a probe would change anything, no matter how innovative.”