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Photonic Laser Thruster Promises Earth to Mars in a Week
serutan writes "Using lasers to drive spaceships has been a subject of interest for many years, but making a photonic engine powerful enough for practical use has been elusive. Dr. Young Bae, a California physicist, has built a demonstration photonic laser thruster that produces enough thrust to micro-maneuver a satellite. This would be useful in high-precision formation flying, such as using a fleet of satellites to form a space telescope with a large virtual aperture. Scaled up, a similar engine could speed a spacecraft to Mars in less than a week."
And if scaled up, cockroaches run at 800mph and fleas could jump over a mile. However, the increase in mass and energy requirements would make it impossible.
Small scale thrusters using only lasers is a good start, but we'll have to see what else gets bigger with scale, other than just the thrust.
To send a ship to Mars in a week, Thrust should be roughly 10m/s^2 times the ship's weight, which we'll say is only ten metric tons. (Because we're getting there in a week, we can pack light... pack light, get it? I slay me.) That gives us 10^5 Newtons of thrust.
Exhaust Velocity is the speed of light, or about 3*10^8 m/s.
So our power consumption is 3*10^13 Watts.
By comparison, the USA is currently consuming less than 1*10^13 Watts on average.
In other words, if think you think it costs too much to refuel an RV now...
It's not completely implausible to use light to propel a spacecraft, but either that propulsion will be ridiculously slow (e.g. solar sails, laser sails, or the "precisely tweak your satellite's orbit a tiny bit" applications mentioned in the article), or it's going to require ridiculous "cheap antimatter" amounts of energy.
That was funny, I'll give you that one. I am an idiot.
Remember, there's a big gap between "likely untrue" and "always untrue." When someone can look at their own statement, realize what it implies about their capacities, and then confidently declare "I am an idiot," they are displaying insight that is well above average, and certainly deserving of mod points.
I, for one, welcome our new self-insight-possessing commenters.
I'm an idiot, too.Singularity: a belief in the "God" idea with the "demiurge" relation inverted.