Hawking and Russian Billionaire Milner want to explore Alpha Centari

For some reason, I find this really fascinating. I'm not usually into the space travel stuff, but this just seems wicked cool.

http://gizmodo.com/a-russian-billionaire-and-stephen-hawking-want-to-build-1770467186

From the article: said: The technology behind the billionaire’s ambitious proposal—of which prototypes were revealed today—includes a “Starchip,” a gram scale wafer carrying cameras, photon thrusters, power supply, navigation, and communication equipment. Propelling that miniature science laboratory is a “Lightsail,” a meter-sized sail that’s only a few hundred atoms thick and weighs a couple of grams. The light sail will be launched away from the Earth by a phased array of lasers, which Milner envisions carrying a combined power of over 100 Gigawatts, similar to the power needed to lift the Space Shuttle off Earth. By directing that much energy at an object weighing just a few grams, we can theoretically accelerate said object up to 100,000,000 miles per hour—a thousand times faster than the fastest spacecraft today. The idea is to launch a small fleet of craft toward Alpha Centauri, allowing us to perform many, many New Horizon-like flybys of our nearest neighbor’s potentially habitable real-estate.

-Rob

totally awesome.

It makes so much more sense than pushing a ton of mass that far. I wonder what kind of attrition rate they're expecting? I would imagine the trade off is reduced radiation/damage resiliency, but I could be wrong. Even if it was high (which I doubt) a small fleet as they put it would give plenty of data. I guess the biggest risk is just making it past all the junk orbiting Earth and then it's smooth sailing. Pun intended.

By my calculations, it will take about 30 years for it to get there at that speed, and then we have to wait another 4.4 years to hear back. (I didn't see this info in the article.)

Matt B wrote: It makes so much more sense than pushing a ton of mass that far. I wonder what kind of attrition rate they're expecting? I would imagine the trade off is reduced radiation/damage resiliency, but I could be wrong. Even if it was high (which I doubt) a small fleet as they put it would give plenty of data. I guess the biggest risk is just making it past all the junk orbiting Earth and then it's smooth sailing. Pun intended.

Not just all the junk orbiting Earth but any junk in the way at all...at 0.25C, no impact with any solid particle, no matter how tiny, would be survivable.

I curious how something that small will have enough transmission power to phone home.

I'll be curious to see how they get a "gram wafer" sized item to broadcast a signal across 4.6 light years. That seems to be the sticking point IMO.

edit: Toyman types faster than me

GameboyRMH wrote:

Matt B wrote: It makes so much more sense than pushing a ton of mass that far. I wonder what kind of attrition rate they're expecting? I would imagine the trade off is reduced radiation/damage resiliency, but I could be wrong. Even if it was high (which I doubt) a small fleet as they put it would give plenty of data. I guess the biggest risk is just making it past all the junk orbiting Earth and then it's smooth sailing. Pun intended.

Not just all the junk orbiting Earth but any junk in the way at all...at 0.25C, no impact with any solid particle, no matter how tiny, would be survivable.

I have read that at relativistic speeds, mass does funky things as well. Your gram size craft, at .2C could punch right through a star or planet. That could be a bad thing.

GameboyRMH wrote:

Matt B wrote: It makes so much more sense than pushing a ton of mass that far. I wonder what kind of attrition rate they're expecting? I would imagine the trade off is reduced radiation/damage resiliency, but I could be wrong. Even if it was high (which I doubt) a small fleet as they put it would give plenty of data. I guess the biggest risk is just making it past all the junk orbiting Earth and then it's smooth sailing. Pun intended.

Not just all the junk orbiting Earth but any junk in the way at all...at 0.25C, no impact with any solid particle, no matter how tiny, would be survivable.

Good point. Even by Mr. Adams's definition there's a lot of "stuff" flying around out there.

Douglas wrote: Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

Regarding the speed and space junk, I would imagine a wafer size craft hitting anything at that speed would be bad. Something larger than two atoms would do serious damage. I wonder if the sail would somehow be expected to deflect something like that?

I would assume power would come from nuclear like many (all?) of our other crafts. I would imagine you could create tiny power with a tiny reactor of some sort. I would assume the thruster would only be for initial launch/setup and that component would detach once the sail deploys and we zap it with the laser. Thereby, only traveling on sail power the rest of the way.

Even if they didn't reach AC or overshot it, imagine the data it would be able to transmit back during the journey.

-Rob

While I'm on an Adams kick, this also seems thinly relevant and meaninglessly tangential to the conversation...

Douglas wrote: In those days spirits were brave, the stakes were high, men were real men, women were real women and small furry creatures from Alpha Centauri were real small furry creatures from Alpha Centauri.

You're welcome.

rob_lewis wrote: I would assume power would come from nuclear like many (all?) of our other crafts. I would imagine you could create tiny power with a tiny reactor of some sort. I would assume the thruster would only be for initial launch/setup and that component would detach once the sail deploys and we zap it with the laser. Thereby, only traveling on sail power the rest of the way. Even if they didn't reach AC or overshot it, imagine the data it would be able to transmit back during the journey. -Rob

Not with a tiny reactor but maybe with a tiny RITEG or optoelectric nuclear battery...although that won't really solve the problem of packing enough energy to transmit a signal back. I'm thinking something like the mother of all RC plane batteries combined with supercaps hooked up to a tiny RITEG for maintenance charge might be the best bet.

I suspect the residents of inhabited planets around alpha centauri will perceive the craft as litter much like a bunch of blowing plastic grocery bags. They will react with anger. Retaliation will be swift and deadly.

In reply to 1988RedT2:

1988RedT2 wrote: I suspect the residents of inhabited planets around alpha centauri will perceive the craft as litter much like a bunch of blowing plastic grocery bags. They will react with anger. Retaliation will be swift and deadly.

Nah, they will make a terrible miscalculation of scale and their entire invasion fleet will be swallowed by a small dog...

We keep finding stuff further and further out that’s gravitationally bound to our solar system….so much so that the best current definition of our edge is where you start finding more AC stuff than our stuff. So, we’re actually just planning a visit to our sister star rather than venturing out into the abyss.

BTW, we get far more asteroids and comets whizzing towards us than any of the models predict based on how much material there should be left over from our system’s formation and the prevailing explanation is that AC is destabilizing material in our Oort cloud and sending it our way causing havoc.

I think those Starchips need to weaponized and deliver an earth style a$$ whipping for taking out our dinosaurs.

The_Jed wrote: In reply to 1988RedT2:

Toyman01 wrote: I curious how something that small will have enough transmission power to phone home.

Check Verizon's coverage map. It's shaded in red.