It seems to be a really good era for extraterrestrial exploration.
In the past few years, a lot has been happening in space, such as the successful landing of the Falcon 9 rocket by SpaceX, and the breathtaking pictures of Pluto sent by New Horizons. This is nearly the furthest distance that humans have ventured thus far.
But in terms of scale, a recently announced space exploration program could easily clinch the title for being the most ambitious: the Breakthrough Starshot Initiative.
That sounds really cool. But what is it exactly?
Breakthrough Starshot is a US$100 Million project funded by venture capitalist Yuri Milner (who apparently got his name from Yuri Gagarin, the first human being in space), and jointly founded by other big shots such as Mark Zuckerberg and Stephen W. Hawking. As its name suggests, the final goal is to send an army of spaceships to the nearest star system to our Sun – Alpha Centauri.
Alpha Centauri (left) is the closest star system to our solar system. On a clear night, it’s usually the third brightest object in the sky.
Despite being the “nearest”, Alpha Centauri is actually 4.37 light years (25 trillion miles) away from us – to put things in comparison, the furthest distance from Earth humans have ever reached, accomplished by the Voyager I spaceship, is merely 10 billion miles. And it took 38 years to reach that distance. It’s like planning a trip from Chicago to LA when the furthest distance we have reached is from the Arch to Tech.
So… how is it able to travel such a great distance?
First of all, the proposed spaceship is not your ordinary spaceship: it weighs approximately the weight of a paperclip. With this amount of mass, scientists are confident that they can propel it to a terminal speed of 0.2c — 20 percent of the speed of light, which is equivalent to 134 million miles/h. That’s like going around the world two times in one second (beat that, Phileas Fogg).
Phileas Fogg, the protagonist of Jules Verne’s 1873 novel Around the World in 80 Days, circumnavigated the globe in 80 days for a wager of £20,000 (that’s worth about $2.95 million dollars today!)
Secondly, the form of propulsion is also not your ordinary form of propulsion – instead of using chemical propulsion fuel and other forms of acceleration techniques such as gravitational slingshot, the project proposes a “light sail” propulsion system, which literally means beams of lasers blasting onto the sail of the spaceship, creating radiation pressure that propels the spacecraft forward. Think of a sailing boat: the light exerting a force on the mirrors of the spaceship is akin to a sail being blown by the wind.
A concept of the light sail propulsion system.
Lastly, the founders do not expect the project to be completed anytime soon – it has an estimated 20 years for design and build, 20 years for the spacecraft to reach Alpha Centauri (assuming no incidents along the way), and 4 more years for the first set of messages to be sent back by the spacecraft. Most of its founders may not be alive to witness the moment of its completion, and perhaps that’s why Mr. Milner is investing billions of dollars in biological research at the same time.
So near, yet so far
Being so ambitious, there are tons of obstacles for the project to go through. Commenting on the potential setbacks of the project, Professor Melville P. Ulmer from the Department of Physics and Astronomy at Northwestern said that the project is unlikely to succeed, due to the sheer number of obstacles to consider.
Professor Ulmer has been the director of Northwestern’s astrophysics program for over 30 years. (Image courtesy of Northwestern University WCAS)
“The biggest challenge is ‘blooming’, where lasers will have a great difficulty passing through the Earth’s atmosphere to reach the space probe”, Professor Ulmer said, “furthermore, if the laser beam is too strong, it may potentially vaporize the spaceship.”
Also, there is a huge challenge in data transmission – our modern signal transmission systems make use of satellite dishes to deliver messages over large distances – but it is almost impossible to install such a device onto the paperclip space probe. What’s the purpose of getting there if we can’t get any messages out from it?
FermiLab is a US Department of Energy national laboratory specializing in high energy particle physics. It’s located in Batavia, IL, about an hour west of downtown Chicago.
Lastly, moving matters to a high speed really requires massive amounts of energy – even if the probe is tiny. “So far, we are able to accelerate particles to 99% of the speed of light in Fermilab,” Professor Ulmer commented, “that’s like one-billionth the size of a strand of human hair, but the lab still has to close down for a period of time in the summer due to its power usage.”
So, there’s a long way to go, folks.
But the story doesn’t end here..
When asked about the possible implications of the Breakthrough Starshot Initiative, Professor Ulmer did mention some of the practical benefits that we can potentially tap into along with this project.
In the 2015 movie The Martian, protagonist Mark Watney had to wait months to get his backup supplies from Earth. If Breakthrough Starshot succeeds, the process would only take a few days.
For instance, although sending space probes to as far as Alpha Centauri seems to be a stretch, we can still utilize similar technology to do things that are more practical – such as sending supplies to our potential colony on Mars.
“Now it takes an average of 9 months to get to Mars, which will simply be too long for the colonization process,” he said. “Imagine we can shorten the time down to a few days – that will greatly speed up the process.”
So for now, we shall see if Mr. Elon Musk is taking this proposal seriously as a viable way to colonize Mars.