The Triple Helix @ UChicago

Spring 2016

"Breakthrough Starshot & The Past, Present, and Future of Interstellar Travel" by Tom Klosterman

 

In March, the scientific community was buzzing with excitement over “Starshot” - the new project initiated by billionaire Yuri Milner’s Breakthrough Foundation: “Starshot.” Starshot aims to demonstrate the possibility of ultra-fast spacecrafts that could achieve interstellar travel within a single generation. For decades, voyages between our solar system and the trillions of other star systems in our galaxy have endured only in the dreams of futurists and sci-fi writers. But now, even Stephen Hawking himself has backed Starshot, joining the ranks of dozens of other expert physicists, astronomers, and astronauts affiliated with the promising venture. 

The celestial target for the glamorous new project is Alpha Centauri, the star system nearest to us. This system likely features Earth-like terrestrial planets, making it a good locale for exploring extra-terrestrial life, and a potential backup plan for humans if we need to flee Earth. 

While traveling through Alpha Centauri, the Starshot mission intends to employ thousands of “Nanocrafts" to record data. Each tiny spacecrafts will weigh only a few grams and carry cameras, thrusters, power supplies, and navigation and communication equipment. Attached to each Nanocraft will be a thin “Lightsail," also only weighing a few grams, which will measure several square meters in area but only hundreds of atoms thick. Both pieces of equipment present monumental engineering challenges, but once achieved, the miniature probes will be able to reach Alpha Centauri in merely 20 years. With current technology, the same journey would span 30,000 years. 

The miniature size of Starshot’s probes is a radical departure from previous interstellar craft designs. One of the earliest serious enterprises was a British study named “Project Daedalus.” During its 5 year life span in the 1970s, the developers proposed a humongous spaceship designed to carry 50,000 tons of fuel, measuring nearly as large as the Empire State Building. For obvious reasons, the ship was never built and the project scrapped. However, the central idea that ‘bigger is better’ has persisted to this day in pop science and science fiction (Think Interstellar), which is why Starshot is so revolutionary. 

In the decades since Daedalus, several other projects have been proposed, both manned and unmanned. In recent years, the most influential group has been “Project Icarus.” Their proposed elegant spacecraft would draw its power from the nuclear fusion of heavy water. It attracted attention for its readily available fuel source and its flashy design; it was even nicknamed “Firefly” for its colorful tail. No doubt, many different designs will be proposed in the years to come, but its may be difficult to imagine a design as promising as Breakthrough Starshot. 

Starshot appears more reasonable than these previous projects because due to its innovative yet practical technologies. Once designed, the Nanocrafts would require few raw materials and each launch would only cost several thousand dollars. 

But not all stages of the project are low scale. After being rocketed into space, an array of lasers on Earth would put the “wind” in the light sails, with “wind” in this case meaning 100 Gigawatts worth of energy, the same amount of power in France’s entire electrical grid — or, the power output of fifteen nuclear power plants. 

The ridiculous amount of energy in the proposed laser array is just one earthly obstacle that Starshot is facing. Even if the international community would permit such a potentially dangerous laser to exist, it would cost billions of dollars. Also, as 20 years would pass before the projected arrival at Alpha Centauri, scientists involved in the early stages of the project might not still be around to see its termination. Another concern is exactly how such minimalist spacecrafts would be able to communicate intelligible information back to Earth. And as there would be a 4-year delay before the information would reach Earth, any errors that the Nanocrafts make in the transmission process would be difficult and time-consuming to detect and correct. But perhaps the most important question is "Why even bother?" 

The most monumental difficulties of interstellar travel proposals are not just the engineering and financial hurdles. The scientific community must be convinced that the journey is worth the time and resources. Every prospective project includes seemingly unattainable levels of technology and cannot promise quick enough results to make the money and effort spent seem immediately worthwhile. However, as Paul Gilster, an expert in the field, says: “History shows that humans are a visionary and exploring species. We will move into the cosmos if we can because it is in our nature”. Momentous scientific pushes often produce advances relevant to everyday life on Earth, and an interstellar mission would be no different. The possibility remains that we may one day have to leave this planet, and Breakthrough Starshot seems to be our best current option to investigate options for our uncertain future.

References

[1] Breakthrough Starshot. "Breakthrough Initiatives." Breakthrough Initiatives. April 12, 2016. 
[2] Brumfiel, Geoff. "Stephen Hawking's Plan For Interstellar Travel Has Some Earthly Obstacles." NPR. April 14, 2016. 
[3] Discovery News. "Sizing Up the Daedalus Interstellar Spacecraft : Slide Show : DNews." DNews. December 12, 2012. 
[4] Gilster, Paul. "Defending the Interstellar Vision." Centauri Dreams. July 27, 2012. 
[5] Ghosh, Pallab. "Hawking Backs Interstellar Travel Project." BBC News. April 12, 2016. 
[6] Lamontagne, Michel. "'Firefly' Starship to Blaze a Trail to Alpha Centauri? : DNews." DNews. February 20, 2015.

 
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