Hi, this is Wayne again with a topic “Stephen Hawking’s Starshot, explained”.
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 $ 100 million into the project called “ Starshot” to see if this type of technology could actually work.. So, let’s break this idea down a bit., It’s known as laser propulsion and works exactly how it sounds. A laserbeam is used to propell a vehicle very rapidly through space., It’s kind of like using a hose to push a ball forward.. The laser’s light carries momentum like the water from the hose, though it’s no where near as powerful., But if you have a big enough laser and a small enough spacecraft, 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 make a tiny, wafer-sized sized spacecraft connected to a reflective sail that stretches a few meters wide, but is only a few atoms thick., It’s kind of like the Planetary Societies, solarsail concept, which uses the suns light to move through space.. The wafer is also meant to hold a number of miniaturized instruments, including a power supply cameras and a communications system. Once the spacecraft is positioned in orbit it’s time to turn on the laser, well, actually lasers.. First, that involves building an array of laser amplifiers on Earth that take up about one square kilometer..
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’s sail.. The lasers will be turned on for about 3-5 minutes, sending the probe through space at 1/5, 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 One spacecraft has been traveling to Alpha Centauri at 40 thousand miles per hour since 1977., And is only .005 % Of the way there. Starshot 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 never been built before, and scientists still need to figure out how to miniturize.
All of the instruments onboard the spacecraft. That includes miniturizing a communications system that can span four light years of space.. The sail also poses an engineering challenge. And needs to be made extra robust, so it can withstand the instense accelerations through space., And it must be as reflective as possible..
If it absorbs too much laser light, then the sail could 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 the 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 redundency 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 $ 100 million for Yuri Milner will help jumpstart some of the research and development needed to prove this technology actually works.. But a project like this is comperable 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 this spacecraft even start. It’S journey to Alpha Centauri. Interested in a much slower form of space transportation Check out of 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, .