Originally posted by twhitehead
Nice idea although I foresee the military stealing it for taking out satellites.
Technology is ALWAYS a two edged sword. You could also use those megawatts of energy to crash fighter jets in combat too. But I wonder if enough power can be concentrated on a craft to actually lift it off the ground. My guess is the first generation would be a hybrid, smaller rocket than usual adding some lift but not enough to get off the ground augmented by megawatts of RF and between the two, the craft launches.
Later generations would probably have enough RF energy to launch with no augmentation rocket.
Also, the higher frequency you use the smaller the dish you need to get the proper focus at X distance.
But the higher frequency you use, the harder it is to generate high RF power, technologically speaking.
I bet they would love to use 100 ghz but try getting 100 megawatts at that frequency.
1 ghz, it would obviously be a lot easier, but the wavelength of 1 Ghz is 330 mm so you would need a really large dish to concentrate 100 megawatts at say, 100 miles up.
100 Ghz has a wavelength of about 3 mm or an area of about 7 mm^2 so you can see a dish of 70 mm^2 would concentrate 10 complete wavelengths at that frequency but at 1 ghz, the wave would occupy about 85,000 mm^2 so to concentrate 10 wavelengths would require 850,000 mm^2 or a dish of 500 odd mm diameter verses 10 wavelengths at 100 Ghz needing a dish of only 5 mm diameter.
Of course the real dishes would be many times bigger but you see the ratio involved.