Exploring our nearest stellar neighbor with really tiny little probes
Back in April, a group called “Breakthrough Initiatives” announced a plan to send a probe across interstellar space to visit Alpha Centauri and send back pictures and other data. All within the next 50 years or so.
Now, on the surface, this sounds kind of crazy. I mean, Alpha Centauri is the closest star system to us, but it’s still 4.39 light-years away! (That’s 4.153×10^13 km, in case you were wondering.)
That’s a hell of a long way away.
In fact, it’s so far away that the fastest spacecraft we’ve ever sent out, New Horizons, would take almost 80,000 years to get there. (If it were even aimed at Alpha Centauri, which it isn’t.)
But, the Breakthrough Initiatives folks aren’t planning on sending a (relatively) slow and bulky old-school probe to Alpha Centauri. Instead, they want to send a swarm of about 1,000 nano-probes on a fly-by mission that would hurtle towards our nearest stellar neighbor at 20 percent the speed of light.
When I say “nano” probes, I’m not kidding. Each probe would have a mass of about 1 gram. (That’s about the mass of a paper-clip!) While it might seem impossible to get any sort of decent sensors in a 1g probe, consider that today’s biggest iPhone (the 6S Plus) only weighs 192g! So, cramming a camera (or two) and a radio into that space shouldn’t be much trouble at all. And if different probes in the swarm have different types of sensors (spectrometers, infra-red, etc.), getting a wide range of data back shouldn’t be any trouble at all.
So, okay. A swarm of tiny probes. That seems doable. But, how do they get there?
Well, obviously, they’ll get there using giant freaking lasers! (GFLs)
You see, rather than carry a propulsion system of its own, each tiny probe will incorporate a reflective surface, called a “solar” or “light” sail. After being placed into local interplanetary space (probably just outside the orbit of the Moon) by a conventional rocket, the nano-probes will be targeted by an array of 100 gigawatt lasers. When the laser pulses strike the probes, the force of the pulse will make the probes the fastest objects ever made by man. In fact, the folks at Breakthrough Initiatives estimate that the entire swarm will quickly accelerate to almost 20 percent the speed of light! At that velocity, it should take the probes about 20 years to arrive at Alpha Centauri!
If that sounds like a long time, remember that it took New Horizons nine years to get to Pluto, and it took Voyager about 36 years just to leave the solar system. Reaching another entire star system in just 20 years would be absolutely incredible!
So, what kind of data might we get back? Well, that depends on the sensors, of course. But, we should expect to at least get back some high resolution images of the three stars that make up the Alpha Centauri system. Hopefully, we’d also get back some photos of the planet that’s believed to be there as well.
Of course, there are a lot of technical issues to resolve before this mission can move forward. First is the creation of the probes themselves. But, that’s probably the least problematic part. Creating the super-powerful lasers, and the tracking systems needed to target the probes over interstellar distances will be another huge issue.
Beyond the technical issues, there’s also the fact that space is filled with things that want to kill you. When you are traveling at 20 percent the speed of light, running into even a tiny dust particle can ruin your whole day. And space is full of dust.
Still, it’s an amazingly ambitious, and tantalizingly plausible plan. We’ve spent the last 70 years or so with our toes in the cosmic ocean. Time, I think, to wade out a little farther.
Steven Disbrow is a computer programmer who specializes in e-commerce and mobile systems development, an entrepreneur, comic-book nerd, writer, improviser, actor, sometime television personality and parent of two human children.
Image courtesy Breathrough Initiatives