Russian billionaire Yuri Milner along with renowned physicist Stephen Hawking announced an ambitious galactic mission last April that involves sending a tiny spacecraft traveling at 20 percent the speed of light to the nearest neighbor star system, the Alpha Centauri. Now, scientists reveal how they can slow down this tiny spacecraft when it reaches Alpha Centauri.
Known as Breakthrough StarShot Initiative, this mission aims to send this tiny spacecraft with the help of new technology called photonic propulsion. This would mean that lasers from Earth will blast on a reflective surface such as a light sail to propel the small probe into high cosmic speeds.
Current technology can reach Alpha Centauri in 20 to 30 years since the probe is traveling at 100 million miles per hour, scientists solved the issue of slowing down the spacecraft to obtain crucial data and observations at this incredible speed.
René Heller and Michael Hippke of the Max Planck Institute for Solar System Research are now planning to not only slow down upon arriving at Alpha Centauri but also to visit the closest Earth-like planet in the system known as Proxima b.
In their proposed plan, the researchers have significantly improved their Breakthrough Starshot plan with a more feasible braking system. This means that they would have to make the probe travel slower at 4.6 percent the speed of light.
According to Hippke, the probe would probably take less than 100 years or twice as long as the Voyager probes, which have been in operations since the 1970s.
By reducing speeds, instead of a laser shot from Earth, the probe will just rely on its light sail deployed in space, as the sun's energy will propel the spacecraft towards Alpha Centauri. Heller adds, this sail will be made from graphene which will be extremely thin and light weight but still strong and highly durable due to its carbon film. This graphene should be coated in highly reflective material in order to propel the probe.
The probe should also be able to successfully send a signal back to Earth when it reaches Alpha Centauri. The launch will use solar energy when the probe arrives, it will utilize uranium-235 or plutonium-239 as its nuclear fuel source to send this signal.
Apart from this, since the light sail will be fully deployed during the journey to Alpha Centauri, particles in interstellar space can potentially damage the craft, while traveling at 4.6 percent the speed of light, which means that the sail should be able to unfurl and fold back when it is not in use.
Unfortunately, the first images of Alpha Centauri will not be seen by our generation as it can take more or less 100 years to arrive at Proxima b. A signal sent back from Alpha Centauri can also take five years to arrive back to Earth at this light speeds.