The project Breakthrough STARSHOT is coordinated by Stephen Hawking , Mark Zuckerberg and the Russian billionaire Yuri Milner. Their goal is to make the first real interstellar trip by leading a fleet of robotic spacecraft, the size of a smartphone, to the vicinity of Alpha Centauri, the nearest star system to the Sun.

An incredible journey of  4.37 light years (44.5 thousand billion kilometers), which would be covered in just 20 years.  Not bad, if you consider that the object’s distance from Earth. Presently, Voyager 1, launched in 1977 in almost twenty years has traveled just 18 thousand light hours.

The details of the mission shall states that the mother ship will take off and release in space a fleet of a thousand miniaturized probes.  These tiny sails will then travel toward Alpha Centauri driven by a series of laser beams sent directly from Earth at a speed of 50 thousand kilometers per second, or about one-fifth compared to that of light.

In twenty years time, the surviving probes would arrive at the star to send precious images and measurements.  The total cost of the mission, as stated on the official website, varies between 5 and 10 billion dollars, of which Milner has pledged to cover 100 million for the first phase of research and development, leading the hunt for future investors.

Pete Worden, former director of NASA’s Ames Research Center, will handle direct operation of the project. They will rely on the collaboration of Avi Loeb, a Harvard astronomer Martin Rees, the British astronomer Saul Perlmutter, Nobel Prize for physics in 2011, Freeman Dyson, mathematician of the Institute for Advanced Study in Princeton, and others.

According to Worden even the European Space Agency was made aware of the mission for future collaborations. They will certainly be necessary, given the enormous economic and technological undertaking of the project.

The most difficult challenge is that of the construction of laser sources that should feed the sails. According to Loeb, the energy source may be a radioactive element such as americium which should generate the power of 100 gigawatts to accelerate the probes up to one-fifth the speed of light; the same power to take off a Space Shuttle and a hundred times that produced by a nuclear power plant.  Laser sources also should be perfectly aligned and synchronized: a slightest mistake would sabotage the whole mission.  But Hawking and company are convinced they can do it.