Can Stephen Hawking’s Starshot Probes Really Make It To Alpha Centauri?

Astronomers have discovered a possible Earth-like world called Proxima b in the Alpha Centauri system and Stephen Hawking’s Starshot probes may go fast enough to cover the distance, but they might not survive the journey.

The Breakthrough Starshot project plans to launch a fleet of wafer-thin nanocraft capable of reaching 20 percent the speed of light, which means they would reach the Earth-like planet in about 25 years.

The problem is that when they travel that fast even a speck of dust can be a major issue.

At one-fifth the speed of light, even a single grain of space dust a hundredth of a millimeter wide could completely destroy the nanocraft, Harvard University’s Avi Loeb told New Scientist.

“Reality comes back to bite you if you try to ignore it.”

Hawking’s Starshot project aims to launch a fleet of wafer-thin nanocraft into space and accelerate them to 20 percent the speed of light using a special light sail. The sail, which would be about 12 feet across, is designed to catch light beamed from powerful ground based lasers back on Earth.

Starshot engineers plan to aim their nanocraft, dubbed wafersats because they’re basically just small circuit boards, at the newly discovered Earth-like world in the Alpha Centauri system so they can send back images of the planet.

Billionaire Yuri Milner announced a $100 million donation to fund basic research into the project, but a full interstellar mission is likely to cost many billions.

Loeb, who heads Milner’s team, has identified 20 challenges to the mission including interstellar space dust and the amount of information the tiny devices would be capable of sending back to Earth, reports New Scientist.

“We did a thorough analysis, taking all the relevant physics into consideration. We didn’t see any showstoppers.”

The team discovered that space dust would hit the probes as a collection of many atoms rather than a single particle, which means the wafersats would essentially be bombarded with tiny objects throughout the entire journey.

Passing through gas would be easier on the probes than space dust, but scientists estimate up to 30 percent of the probe could be destroyed by the time it reaches the Alpha Centauri system.

If Voyager1 left our planet when humans first left Africa 75,000y ago, it would just be arriving at Alpha Centauri pic.twitter.com/hFmcL7afyR

— ????? (@StarStuff_ivan) August 24, 2016

To help reduce the damage, the wafersats are being designed with a few millimeters of empty graphite on the front of the probe to act as shielding. The craft is also designed to be long and thin to reduce the chance of a head-on collision.

It’s also important to consider the amount of hardware that would fit on the tiny wafer-thin probes; they might only be able to carry very small instruments capable of only rudimentary examination of the Earth-like world.

Hopefully, by the time they’re launched into space, technology would have advanced enough to make the mission worth the billions of dollar the project is projected to cost. Estimates put the total mission to Alpha Centauri at $10 billion, about the amount it cost to build the Large Hadron Collider, the largest particle accelerator in the world.

Relative sizes and distances of stars: Sun, #ProximaCentauri, Alpha Centauri A & B pic.twitter.com/UdmrFLL0fo

— Dr. Bruce Betts (@RandomSpaceFact) August 24, 2016

Before any of that can happen, however, the probes must first be built. Wednesday, Pete Worden, chairman of the Breakthrough Prize Foundation, told Space.com that a committee of scientists had met and discussed plans to build a prototype of Hawking’s Starshot probes. A full interstellar mission, however, is at least 20 years away.

“We certainly hope that, within a generation, we can launch these nanoprobes. And so perhaps 20, 25 years from now, we could begin to launch them, and then they would travel for 25 years to get there.”

Once the space probes reach the Alpha Centauri system, it would take 4.22 years for any information they send to reach Earth.

Do you think it’s worth billions of dollars to send Stephen Hawking’s wafer probes towards the Alpha Centauri system?

[Image via Breakthrough Starshot/YouTube]