Is Interstellar Travel Really Possible?

The very aspect of space that makes it so interesting—its unknown vastness—is also the biggest challenge we face when attempting to explore it. Is interstellar space exploration, even to the nearest stars, really feasible?

Sabrina Stierwalt, PhD
5-minute read
Episode #191

Is Breakthrough Starshot really possible?

But can we really build not just one but thousands of spacecraft that are so tiny as to not require a significant amount of radiation pressure to send them over such a large distance but that can also survive the high energy laser beams for several minutes? Can we really create laser beams that can be used in unison at such high powers while focused on such tiny targets that are tens of thousands of miles away?

The feasibility of such an effort is exactly what the funding announced last week hopes to address. The $100 million pledged by the team led by Yuri Milner will serve as an investment to explore the production of prototypes for both the laser array and the nanocraft themselves. Also on the Breakthrough board along side Milner are renowned theoretical physicist Stephen Hawking and Mark Zuckerberg, the man who brought us Facebook. The research will be led by the former director of the NASA AMES Research Center, Pete Worden, with the support of an advisory committee which includes Ann Druyan, an Emmy and Peabody award winning author and producer who co-wrote Cosmos with Carl Sagan who later became her husband, and Mae Jemison, the first woman of color in space and a leader in efforts to explore beyond our solar system.

However, this initial $100 million will only buy a proof of concept. Worden has already estimated that the price tag on the full project, should the initial investment prove successful, would be closer to $10 billion. Such a cost is more in line with current large scale astrophysical research endeavors like the Large Hadron Collider in Geneva.

And even though the whole idea may sound far fetched, the details of Breakthrough Starshot are based in several currently cutting edge technologies where scientists and engineers are making significant recent progress. The industry surrounding the development and manufacturing of thin, light weight materials on nanoscales, like graphene, is currently exploding thanks to their many, very practical uses including desalination.

The Planetary Society is also testing the feasibility of the light sail technology via their citizen-funded LightSail project. The nonprofit group conducted a successful test flight in June 2015 with the goal of moving toward the launch of a small spacecraft carrying large, reflective sails into orbit around the Earth. Sometime in 2016 they plan to launch a demonstration of the craft’s solar sailing capabilities, a launch that will involve the help of the Falcon Heavy rocket from the private spaceflight company SpaceX.

What can we learn from visiting Alpha Centauri?

So what can we learn from visiting Alpha Centauri? For starters, knowledge of our nearest stellar neighbors will give us insight into how alone our human-inhabitable world is in the vastness of space. One planet is already known to exist in the triple star system, and, should the larger vision of Breakthrough Starshot become a reality, Alpha Centauri is sure to become the target of extensive investigations into other possible exo-worlds.

The mission will also fundamentally alter our relationship with space travel and ultimately the universe. Given all that we already know about the cosmos, it can be easy to forget that the farthest we have ever sent probes, the extent of our solar system, is almost insignificant when placed into context of the entire observable universe. Not to mention the fact that we humans have never made it past the Moon, our nearest neighbor at 230,000 miles. Space exploration is extremely challenging, but that challenge inspires people to learn more about our relation to the cosmos and even to become scientists or engineers themselves. It’s hard to put a price tag on that.

Until next time, this is Sabrina Stierwalt with Ask Science’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Ask Science on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com

Image courtesy of the Planetary Society and NASA.


Please note that archive episodes of this podcast may include references to Ask Science. Rights of Albert Einstein are used with permission of The Hebrew University of Jerusalem. Represented exclusively by Greenlight.

About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.