Gadgetory

let's get this straight a bunch of scientists including Stephen Hawking want to send a tiny spacecraft to the next closest star using a giant laser Russian billionaire Yuri Milner has already invested a hundred million dollars into the project called star shot to see if this type of technology can actually work so let's break this idea down a bit it's known as laser propulsion and works exactly how it sounds a laser beam is used to propel a vehicle very rapidly through space it's kind of like using a hose to push a ball forward the lasers light carries momentum just like the water from the hose though it's nowhere near as powerful but if you have a big enough laser and a small enough space craft you can potentially transmit enough force to the probe so that it moves very very fast that's what Hawking and Milner want to do the idea is to create a tiny wafer size spacecraft connected to a reflective sail that stretches a few metres wide but is only a few atoms thick it's kind of like the Planetary Society solar sail concept which uses the sun's light to move through space the wafer is also meant to hold a number of miniaturized instruments including a power supply cameras and a communication system once the spacecraft is positioned in orbit then it's time to turn on the laser or actually lasers first that involves building an array of laser amplifiers on earth that take up about one square kilometre one laser is fed into these amplifiers which break the light apart into thousands of beams the directions of those beams can be adjusted to form one giant beam of light that travels up out of Earth's atmosphere and hits the spacecraft sail the lasers will be turned on for about three to five minutes sending the probe through space at one-fifth the speed of light at that pace the spacecraft should get to Alpha Centauri in a mere 20 years that may seem like a long time but you have to remember that Alpha Centauri is four light years away that's 25 trillion miles for comparison NASA's Voyager 1 spacecraft has been traveling to Alpha Centauri at 40,000 miles per hour since 1977 and it's only point zero zero five percent of the way their star shot sounds really cool but there's still a lot of work to be done before this idea can become a reality the array of lasers needed for propulsion has ever been built before and scientists still need to figure out how to miniaturize all the instruments onboard the spacecraft that includes miniaturizing a communication system that can span four light-years of space the sail also poses an engineering challenge it needs to be made extra robust so that it can withstand the intense accelerations through space and it must be as reflective as possible if it absorbs too much laser light the sail can melt additionally the path between Earth and Alpha Centauri isn't exactly empty the chances of hitting something big like an asteroid are small but lots of interstellar dust still stands in the way and with a spacecraft moving at 1/5 the speed of light hitting just a tiny speck of dust will pack a big punch engineers will have to build a redundancy system for the sail so that it can withstand a few high speed dust collisions along the way and of course there's always money to consider the hundred million dollars from yuri milner will help jump-start some of the research and development needed to prove this technology actually works but a project like this is comparable to cern or the apollo program it's going to need billions of dollars to succeed that means it could be many years before we see the spacecraft even start its journey to Alpha Centauri interested in a much slower form of space transportation check out our video on the ExoMars mission or if planets are more your jam we break down if there is a mysterious planet 9 at the edge of our solar system