Hawking Backs $100 Million Interstellar Travel Project to Send 'Nano-Craft' To Nearest Star

At a press conference on Tuesday, Russian entrepreneur Yuri Milner, cosmologist Stephen Hawking and a group of scientists and philanthropists announced a $100 million research program to send robotic probes to nearby stars within a generation. The group believes that using a nano-spacecraft propelled by lasers, they will be able to reach Alpha Centauri in just over 20 years after launch. The nearest star system is 40 trillion km away, which using current technology would take about 30,000 years to reach there. The aforementioned group said that thanks to their research and development, they might be able to make a spacecraft that could cut down the duration to 30 years. Reuters reports: Tuesday's announcement, made with cosmologist Stephen Hawking, comes less than a year after the announcement of Breakthrough Listen. That decade-long, $100 million project, also backed by Milner, monitors radio signals for signs of intelligent life across the universe. Breakthrough Starshot involves deploying small light-propelled vehicles to carry equipment like cameras and communication equipment. Scientists hope the vehicles, known as nano-craft, will eventually fly at 20 percent of the speed of light, more than a thousand times faster than today's spacecraft. "The thing would look like the chip from your cell phone with this very thin gauzy light sail," said Pete Worden, the former director of NASA's Ames Research Center, who is leading the project. "It would be something like 10, 12 feet across."The Atlantic has just published an in-depth report on this, also explaining how this project came to being. You can also watch the live stream of the press conference.

Comments

Interesting, but..

[wbr1]

I love the idea. However with a device that small, how do we get a signal back? It will not be able to generate a strong radio or light signal to send back. Would we be able to use existing radio telescopes to pick it up, or would we need better receiving infrastructure?

Re:Interesting, but..

[wbr1]

You cannot use entanglement to communicate at least an not currently understood. A receiver reading the spin or other property of a particle cannot determine if the measurement they make is a result of taking the measurement or the particle having been changed at a distance.

Re:Interesting, but..

[tylersoze]

There wouldn't really be any commands to execute, all they are doing is basically shooting the probes towards Alpha Centauri.There wouldn't be anyway for them to manuever, it's not like they'd be able to slow down and get into orbit.

Re:Interesting, but..

[NEDHead]

If you have a continuous stream of launches, it would be simple to create a mesh network (for redundancy) that daisy-chains the length of the path to relay signals.

And by having a large cluster of detector devices you can have an arbitrarily large collective system for high resolution.

Re:Interesting, but..

[NEDHead]

Sure is. Which is why it requires creative solutions. And if they travel at 0.2C, and you launch every second then you have separation of about 60KM. That represents about 150 million units per light year to the target, or 600M to AC, spread over 20 years at, say $20 each so $600M per target per year, or one Shuttle launch per year

Re:Interesting, but..

[Rei]

The odds that a Slashdot reader will suggest quantum entanglement as a communications approach approaches 1 as a space-related thread grows ;)

There are people discussing the issue in the comments section on the Starshot page. For my two cents: given the described craft, which is to have a very flat sail and very high pointing accuracy.... it's really simple. You have a ~100GW class laser on Earth as a fundamental requirement of the proposal. Point it at your craft and fire. Even at those distances, the reflected light will be vastly more than such a tiny "chip" on the sail could ever possibly produce. As for how to modulate the signal, again, that's not tricky. Put a tiny piezoelectric vibrator in your chip. Even tiny vibrations will throw off the phase and particularly the pointing accuracy of the sail. If the vibrations aren't self-damping the you can use active damping to cancel them out.

When I first heard about this concept, my reaction was mostly "keep dreaming". But actually it's starting to sound more plausible (if they can work out the sail and nanoprobe, that is). For example, the lasers. 1TJ at 20% net system efficiency and industrial power rates of $0,05/kWh is only $70k. There's nothing unaffordable about that - even if your costs work out to be dramatically higher it would still be quite reasonable. But what about storing and then discharging such vast amounts of power? No need - use a chemical laser and store the feedstocks. Chemical lasers also give you the highest power outputs anyway because they discharge their heat in the exhaust, like rocket engines.

In particular, I'm looking at something like COIL. Discharge into water to recover the iodine as iodic acid, then recover elemental iodine from that through dehydraton followed by reaction with carbon monoxide. Elemental iodine is solid, so you can store it in a big pile if you wanted. The other side of the laser involves creating excited oxygen. COIL does it by reacting a mixture of hydrogen peroxide (produced by the anthraquinone process from hydrogen and water) and KOH with Cl2 (KOH and Cl2 produced from the resultant KCl by the chloralkali process). But alternative reactions might allow for lower capital cost storage, particularly in terms of avoiding Cl2 tankage. But if we assume that a traditional COIL approach is used, then what you need to drive the regenerative processes are carbon monoxide, hydrogen, and electricity. It just so happens that those are the three things you get from the partial oxidation of methane (aka natural gas) driving generator. Natural gas being the cheapest available fuel source in many areas.

Total stored feedstock mass for the laser should be on the order of several hundred tonnes. The most expensive chemical involved by far is elemental iodine, which is $30/kg. So no capital cost problem there. So it just comes down to the capital costs on the lasers and associated optics hardware.

Really, I'm not seeing any roadblocks in this regard.

Obligatory Fermi

[Applehu Akbar]

So why hasn't "someone" done this already?

Re:Obligatory Fermi

[Athanasius]

You can't collimate a laser beam that perfectly. When I looked into that some time recently I believe for a visible red light laser you'd see significant dispersion after less than 10km. Yes, in a vacuum. Even if you could align the internals perfectly you'd still get a small amount of diffraction where the beam leaves the apparatus.

Over lightyears you're never going to maintain beam cohesion.

This also both answers the GP's question for the period of time the such a probe is being accelerated and why it wouldn't be accelerated the whole distance. Indeed given the travel time, even if accelerated to very close to the speed of light, you'd not be aiming the laser at the destination system (it would move some by the time the probe got there).

Re:Obligatory Fermi

[Lab Rat Jason]

The write up on Ars Technica basically stated this... accelerate it to 20% speed of light within a very short span (half hour if I remember correctly), and send multiple devices for redundancy... Once the technology was built, there'd be no reason not to send thousands of them.

Starwisp

[seanellis]

Something like this was proposed many years ago by Robert L Forward, called Starwisp. See https://en.wikipedia.org/wiki/... for details.

The probe would be very light but extended, like a cobweb. Tiny processor/sensor nodes would exist where the wires touched. Some nodes and web filaments would undoubtedly be destroyed by dust collisions en route, but would be multiply redundant. On arrival, the probe would be tattered and torn but still functional.

Re:0.2C

[Rockoon]

More than a few probes have mysteriously been lost.

The fastest (relative to our sun) thing ever recorded in our solar system was only a few percent of the speed of light. We can treat all the rocks and dust in the solar system as basically standing still when talking about the relative speeds that this probe will take on.

Basically, you are talking out your ass, waving your hands about data that wouldn't apply if it were true, but isnt even true.

Re:0.2C

[Eloking]

Um, small or not, have they considered how the craft is going to be shielded against collisions at that speed? Even something as small as a grain of sand at 0.2C packs quite a wallop. Also, is radiation an issue at that velocity?

Collisions at 0.2C? Hell, even at 100 MPH (160Km/h) the probe will be pretty much destroyed.

The magic is that most of the universe is, well, empty. I didn't do the math for this particular case, but I remember one of NASA scientist that made such calculation of the probability of a collision of the voyager probe for the next millennium. It was several digit after the decimal point.