Russian billionaire Yuri Milner, and others from the assembled team, announced a $100 million plan for interstellar flight using “nanocraft” filled with sensors traveling at 20% the speed of light in order to reach the closest stars to Earth by sailing on laser energy provided by a massive Earth-based laser.
“Starshot” starts with science fiction
Flanked by Stephen Hawking and other scientific scientific luminaries in New York earlier this week. Yuri Milner announced that the group he’s assembled and will be funding a program to build spacecraft about the size of postage stamps, that will be loaded in an Earth-orbiting mothership to be released into an orbit of their own. Once they are ready, the nanocraft will deploy sails that will be targeted by a laser in order to send them hurtling towards distant stars at 134 million miles per hour within minutes of catching their waves.
With existing technologies and Moore’s Law, the group believes that they will be able to miniaturize what they need in the “one generation” timetable laid out by the space-loving astronomical philanthropist. If NASA could take back many of the probes they launched in the last decade, they would be able to fill them with additional sensors as technology and computing power gets exponentially more powerful while at the same time getting smaller.
The “sailing of a laser” idea, strangely, isn’t that big of an ask. On paper it’s already feasible, if only when compared to what would be required to make teeny tiny nanocraft with even smaller fusion reactors for propulsion. Unlike sailing on laser beams, little fusion reactors would require nothing less than a massive technological leap.
But, this idea isn’t without challenges of it’s own as explained by Jonathan McDowell, a scientist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. McDowell is not on the “Starshot” team, but believes that these “nanocraft” could simply be melted by the laser pulses if the light isn’t shone correctly.
“You’re pumping a lot of energy into this object,” he told Space.com, referring to the Starshot nanocraft. “You’d better hope 99.9 percent of it gets reflected.”
Space isn’t empty
Even the often careless Han Solo, took the time to calculate the course taken prior to jumping to light speed as he explained to Luke in the first film in the Star Wars franchise. You can’t just go to light speed and not hit anything. “The interstellar medium isn’t zero,” McDowell said referring to the possible obstacles the nanocraft could hit on their way to our closest stars.
At 134 million miles per hour and the size of a postage stamp, the nanocraft would struggle with a collision with dust.
McDowell pointed out on Tuesday, the day after Milner and his team introduced the initiative, that a bit of space dust the size of a grain of sand would essentially act like a pound of dynamite in the event of a collision with a nanocraft moving at 20% light speed.
McDowell isn’t completely rubbishing the “Starshot” team’s ideas, just looking at the inherent difficulties at present. Acceleration poses a problem as the nanocraft would go from 0 to over a 100 million miles an hour and minutes and that means “pulling Gs.”
Additionally, the laser array that would be required to provide the “wind beneath the sails” of the nanocraft, would require a phased laser array (sticking with the Star Wars reference, a la the Death Star) where multiple lasers come together into a single combined beam.
That’s tricky, but doable. What might not be possible is powering a phased array laser that would be comprised of thousands of optical elements spread over square miles sufficiently.
McDowell made it clear, he’s not hating on the project. In fact, it’s just the opposite in his mind.
“When physicists start to pick it apart, it’s a way we show the love,” he said.
$100 million goes a long ways
Breakthrough Starshot is why geniuses go into the sciences. When initiatives like this get private funding, all the better. Fighting with governments for this type of money for something that sounds so out of the box is nearly impossible and securing funding year in and year out is also near impossible.
Tangible results are the measuring stick for most projects like this, but with Mr. Milner’s interest, this is a hurdle that has already been cleared.
With a sizable budget and 20 years’ time, a lot can happen. Hell, just look at your phone and compare it to your phone of five years ago. Now, put some of the brightest minds in the world on it and well….anything is possible?