The Flying Cell Phone to Alpha Centauri: Part One

Welcome ! For a little escape from the Solar System, let us take a look at the “Breakthrough Starshot” mission. The plan is to send a spacecraft to the nearest star apart from the Sun, Alpha Centauri, and to make that journey in only 20 years. This should impress you because the only objects deliberately launched from Earth that have left the Solar System, the Voyagers 1 and 2 satellites, require 200,000 years to achieve the distance of this nearest stellar neighbor, Alpha Centauri.

The actual spacecraft must be a very light one gram, or the weight of a single raisin. This feather-light construction already sounds like a tall order, but, recall that the processor of a cell phone has significant computing power yet is not much more than a factor of ten times more massive than what is required. Moving along, this “nanocraft” must also be able to travel at breakneck speeds of about one-tenth the speed of light, or 110 million km/hr (70 million mph). While no such satellite yet exists, the chosen approach for going fast is to attach a sail that “catches” a beam of laser light, rather like a sailboat mainsail that catches the wind.

On arrival to Alpha Centauri, this flying cell phone will take photos of Alpha Centauri and its planetary system and send them back to Earth. Having said that, in this case the journey will be as interesting as the destination. This is because the nanocraft may pass near to other objects along the way, such as the object in the outer Solar System that was proposed to exist by its gravitational influence on smaller icy bodies, but has not yet been detected. The most natural explanation is that this so-called “Planet 9” is, as the name implies, a massive planet. It has also recently been proposed that “Planet 9” may be a small black hole. Stay tuned for the next installment in which I will discuss this interesting second possibility that a small black hole lurks in the outer Solar System.