Josh, what is the payload size of the railguns that achieve 'twice orbital velocity'?<br /><br />Firstly, ANY use of such velocity in atmosphere dense enough to float an airship is going to incur massive aerodynamic losses from hypersonic shock effects.<br /><br />Secondly, the length, mass and power requirements of mass drivers scale with the payload size, so an 80' long mass driver that drives a 100 gram payload is going to be monstrous to drive a 100 kg payload.<br /><br />Thirdly, how are you going to power your airship mass driver? You going to run an extension cord to the surface? How are you going to accumulate the power for the shots? You are talking some significant mass for the capacitors. I happen to know quite a bit about mass drivers, I've built a few, so I know what requirements they have.<br /><br />If I "slam" your ideas Josh, it is because you've established a reputation on this forum of making unsupported assertions without backing them up with any numbers, calculations, or references. You don't do your homework. <br /><br />You shouldn't expect any better treatment from any other objective scientific forum intent on anything other than lip flapping.