Brian M
Seems quite plausible for short 'commuter' hops say to Mars - but not really suitable for longer distances. Perhaps energy harvesting along the way is the way for future interstellar ships
NotoevmsAdmin
how do you come back?
Tommo
This would also be ideal for deflecting the odd errant asteroid that may be coming our way.
Gizmowiz
I think being able to contain anti-matter would solve a lot of the fuel problems since the power contained in that is many orders of magnitude higher than nuclear power of the sun itself.
piperTom
Philip Lubin is an optimist... or perhaps just a nerd. Any laser big enough to generate usable thrust is just a software change away from being a weapon. 70GW is plenty to burn a city. What country is going to sit idle while another country builds such a thing?
Talk of wafer scale probes also misses an hard requirement for any probe: it must be able to send data home. Even for the closest stars, and even allowing for the invention of very short wave length lasers, this means a BIG aperture, several meters.
c2cam
@Brian M - I agree with you on this. Taking advantage of your surroundings and harvesting energy as you go seems logical to me. Relying on an ever increasing distant and volatile source to power a spacecraft seems rudimentary. Having a small, powerful, safe, and as yet undiscovered power source you could take with would be ideal, but outside that, the ultimate would be manipulating your current environment as a means of propulsion.
And piperTom brings up a very good point.
08bd1b6f62e64e09a2621e9f7f3b3c8e
How do you stop it? At the speeds indicated, it would not orbit Mars when it got there. The trajectory might be slightly bent by Mars' gravity but the probe/craft would just keep shooting out into interstellar space. The idea actually seems whacky. Even putting a huge laser array in orbit around Mars to slow the craft down would mean halving the overall speed--accelerate halfway, then turn on the Mars array to decelerate the remaining distance.
sgdeluxedoc
As others have said here.. Mars.. sure at 2% we could even send instructions to the ship in a reasonable amounbt oif time.. less than a one day wait for confirmation., MUCH better than radio waves! But heading to the stars.. even reaching something only 20 light years away at 25% the speed of light would take 100 years MIINIMUM to get any information from.. if the info was sent bac AT the speed of light. A noble venture, sure, but I wonder if the math *really* properly takes into account the huge increase of mass of the ship at those speeds. Would lasers really have the ability to propel what would eventually become a near infinitely massive ship.. or perhaps the momentum is what they're factoring in. Fine.. but what about braking at those speeds? I can't even fathom their math.. it's way beyond my capabilities to program.. However.. if they believe they can do it.. they probably can!
James Donohue
This work was formerly being led by Leik N. Myrabo, who has since retired: http://www.lightcrafttechnologies.com/rpi_www/personnel/myrabo.html
attoman
This a very old idea although I'm sure the Santa Barbara crowd has refined it somewhat. It was always an idea that met hard science criteria. This author dismisses it as Science Fiction and implies that some magical discovery has transformed the idea into possibility, best to dismiss the author.
It's happened more then once that a good idea is recast by a member of academia. As truly great idea men like Leo Szilard can attest it requires will and resources to get proper credit for your creations.